NLRP3 inflammasome activation is pivotal for cytokine secretion and pyroptosis in response to diverse stimuli,playing a crucial role in innate immunity.While extensively studied in mammals,the regulatory mechanisms go...NLRP3 inflammasome activation is pivotal for cytokine secretion and pyroptosis in response to diverse stimuli,playing a crucial role in innate immunity.While extensively studied in mammals,the regulatory mechanisms governing NLRP3 activation in non-mammalian vertebrates remain largely unexplored.Teleosts,as basal vertebrates,represent an ideal model for exploring the evolutionary trajectory of inflammasome regulation.In this study,ABE assays,confocal microscopy,and biochemical analyses were applied to systematically characterize the mechanisms underlying NLRP3 inflammasome in teleosts,using large yellow croakers(Larimichthys crocea,Lc)and zebrafish(Danio rerio,Dr)as representative models.Our findings revealed a previously unrecognized palmitoylation-dependent regulatory mechanism essential for teleost NLRP3 activation.Specifically,zDHHC18-mediated palmitoylation at a teleost-specific cysteine residue(C946 in LcNLRP3,C1037 in DrNLRP3)was required for the translocation of NLRP3 to the dispersed trans-Golgi network,facilitating its subsequent recruitment to the microtubule-organizing center.This membrane trafficking was crucial for inflammasome assembly and downstream inflammatory responses.These findings provide new insights into the distinct regulatory mechanisms of NLRP3 activation in teleosts,highlighting an evolutionary divergence that contributes to innate immunity adaptation in early vertebrates.展开更多
Sex-biased microRNAs(miRNAs)influence gonadal development in fish by directly targeting genes associated with estrogen production pathways.WW domain-binding protein 2(WBP2)functions as a crucial transcriptional co-act...Sex-biased microRNAs(miRNAs)influence gonadal development in fish by directly targeting genes associated with estrogen production pathways.WW domain-binding protein 2(WBP2)functions as a crucial transcriptional co-activator of the estrogen and progesterone receptors(PGR).This study investigates the direct modulation of a sex-biased miR-133b on wbp2 and its regulatory role in gonadal development in fish,the greater amberjack(Seriola dumerili).Using dual-luciferase reporter assays,we demonstrate that wbp2 is a direct target of miR-133b,with miR-133b-3p binding to the 3'untranslated region(3'UTR)of wbp2.In vitro,miR-133b mimic significantly downregulate wbp2 expression,while the miR-133b inhibitor increase wbp2 levels.Consistently,in vivo,wbp2 expression is upregulated following antagomir-133b treatment and downregulated following agomir-133b.RNA fluorescence in situ hybridization(RNA-FISH)results reveal miR-133b and wbp2 co-localization in ovarian interstitial cells.Notably,phylogenetic analysis indicates that miR-133b-3p and wbp2 are highly conserved among bony fish species.Additionally,dual-luciferase assays in other bony fish species including Oreochromis niloticus and Danio rerio also confirm the targeting effect of miR-133b-3p on wbp2,suggesting that this regulatory mechanism is conserved across bony fish.This research provides a theoretical foundation for further exploration of non-coding RNA-mediated regulation in gonadal development in teleost.展开更多
AIM To identify the type localization andmorphology of APUD endocrine cells in thegastroenteropancreatic(GEP)system ofstomach-containing teleosts,and study APUDendocrine system in the stomach,intestine andpancreas of ...AIM To identify the type localization andmorphology of APUD endocrine cells in thegastroenteropancreatic(GEP)system ofstomach-containing teleosts,and study APUDendocrine system in the stomach,intestine andpancreas of fish species.METHODS Two kinds of immunocytochemical(ICC)techniques of the streptavidin biotin-peroxidase complex(SABC)and streptavidin-peroxidase(S-P)method were used.Theidentification,localization and morphology ofAPUD endocrine cells scattered in the mucosa ofdigestive tract,intermuscular nerve plexus andglandular body of northern snakehead(Channaargus),ricefield eel(Monopterus albus),yellow catfish(Pelteobagrus fulvidraco),mandarinfish(Siniperca chuatsi),largemouthbass(Micropterus salmoides),orientalsheatfish(Silurus asotus),freshwater pomfret(Colossoma brachypomum)and nile tilapia(Tilapia nilotica)were investigated with 8 kindsof antisera.RESULTS The positive reaction of 5-hydroxytryptamine(5-HT)immunoreactiveendocrine(IRE)cells was found in the digestive tract and glandular body of 8 fish species indifferent degree.Only a few gastrin(GAS)-IREcells were seen in C.argus,M.albus and P.fulvidraco.Glucagon(GLU)-IRE cells were notfound in the digestive tract and glandular bodybut existed in pancreatic island of most fishspecies.The positive reaction of growthhormone(GH)-IRE cells was found only inpancreatic island of S.Chuatsi and S.Asotus,no positive reaction in the other 6 fish species.Somatostatin(SOM)-,calcitonin(CAL)-,neurofilament(NF)-and insulin(INS)-IRE cellsin the stomach,intestine and pancreas of 8 kindsof fish were different in distribution and types.The distribution of all 8 APUD cells was the mostin gastrointestinal epithelium mucosa and then indigestive glands.The positive reaction of SOM-and 5-HT-IRE cells was found in intermuscularnerve plexus of intestine of P.fulvidraco andS.chuatsi.Only GH-IRE cells were denselyscattered in the pancreatic islands of S.chuatsiand S.asotus,and odd distribution in thepancreas of S.asotus,SOM-IRE cells weredistributed in the pancreatic islands of S.asotus,C.Brachypomum and T.nilotica.There were INS-IRE cells in the pancreaticislands of S.chuatsi and S.asolus.Eightkinds of APUD cells had longer cell body andcytoplasmic process when they were located inthe gastrointestinal epithelium,and had shortercell body and cytoplasmic process in the gastricgland,and irregular shape in the esophagus andpancreatic island.CONCLUSION Eight kinds of IRE cells were identified in the GEP system of stomach-containing teleosts. These endocrine cells were scattered in gastrointestinal mucosa, intermuscular nerve plexus, gland body, pancreatic gland and islands under APUD system. CAL- and GH-IRE cells in the pancreatic islands of fishes showed functional diversity for these two hormones. Their morphological feature provides evidence of endocrine-paracrine and endocrine-exocrine acting mode. This research can morphologically prove that the GEP endocrine system of fish ( the lowest vertebrate) is almost the same as of mammal and human.展开更多
Toll-like receptors(TLRs) sit at the top of the immune system pyramid.They form a paramount family of immune sentinels capable of sensing diverse microbe-associated molecular patterns(MAPMs),danger/damage-associated m...Toll-like receptors(TLRs) sit at the top of the immune system pyramid.They form a paramount family of immune sentinels capable of sensing diverse microbe-associated molecular patterns(MAPMs),danger/damage-associated molecular patterns(DAMPs),and other signals.These perceptions trigger immediate innate immunity and instruct subsequent adaptive immunity.TLRs are highly glycosylated type I transmembrane glycoproteins that share a conserved tripartite domain architecture(LRR,TM and TIR domains),classified into six subfamilies(TLR1,TLR3,TLR4,TLR5,TLR7,TLR11) in vertebrates.Upon ligand engagement,TLRs form homodimers or heterodimers to activate immune responses via SMOCs,orchestrated by intrinsic and pathogen-directed negative regulators,glycosylation modification,etc.TLR signaling culminates in the production of inflammatory cytokines,interferons,inflammasomes,immune cell activation,apoptosis,etc.Teleosts,as the largest and most diverse group among the extant vertebrates,manifest important economic value and are crucial for understanding the evolution of vertebrate immunity.To date,teleosts contain 20 TLRs(TLR1–5,TLR7–9,TLR13,TLR14,TLR18–23,TLR25– 28) with expansions and losses in different species,and most of them possess more or less variants.Almost all teleostean TLRs localize in organelles,such as endosomes and lysosomes,sensing not only pathogens and DAMPs but also trophic factors and environmental stresses(hypoxia,temperature,microplastics,etc.).Most ligands for TLRs remain undetermined in teleosts.The adaptors consist of My D88,TIRAP,TRIF,SARM1,BCAP and SCIMP,but without TRAM;however,half of the corresponding relationships between TLRs and adaptors remain unknown in teleosts.Neofunctionalization often emerges during evolution in teleostean TLRs.Here,a systematic review of TLR signaling in teleosts,from the perspective of comparative immunology,presents the current understanding of the functions and mechanisms of teleosts.Additionally,it provides strong evidence of a divergent TLR signaling repertoire with the species-specific variation among teleosts.These are expected to benefit novel adjuvants,aquaculture,fish immunology,and comparative immunology.展开更多
Endocrine disruptors(EDs)are synthetic or natural chemical molecules occurring in environment that have the potential to impart adverse effects on homeostasis of endocrine axis leading to neurological,developmental,im...Endocrine disruptors(EDs)are synthetic or natural chemical molecules occurring in environment that have the potential to impart adverse effects on homeostasis of endocrine axis leading to neurological,developmental,immunological and reproductive disarray at organismal level.A wide range of structurally diverse EDs such as,sex-steroid hormone mimics,pesticides and fertilizers,prevail in the environment originating from waste of industries,pharmaceutics,sewage treatment plants and agriculture.In addition,some metals,such as Cu,Hg and Zn,have endocrine disrupting potency in their metallic as well as synthesized nano-particulate forms.There is an increasing concern in research for the plausible threat posed by EDs that can disrupt the endocrine system in aquatic fauna as these compounds are frequently discharged or run-off into water stream.Fishes are well known bio-indicators to understand toxicity of EDs as they are vulnerable to endocrine disruption.Furthermore,EDs have the potential to affect fish-feeding higher vertebrates including mammals and subsequently human,as they make their way up on the food web pyramid due to biomagnification.In light of this,several observations suggesting adverse effects of EDs and the mechanism contributing to endocrine disruption in fish are discussed extensively in this review.This article highlights the necessity to choose a credible model for assessing the toxic effects exerted by EDs.Furthermore,the toxic effects of EDs will be comprehensively reviewed with reference to sexual plasticity,neuroendocrine mechanisms,thyroid and immune modulation,gonadal development and maturation as well as changes in transcriptome/genome profile using fish models to imply ED-induced aquatic pollution in a larger perspective.For decades now,studies on EDs have challenged traditional concepts in toxicology to develop new molecular markers to improve methodologies and to assess the ecological risks associated with field conditions.In this regard,it is imperative to highlight the development of modern diagnostic tools including biosensors to monitor the inadvertent usage of EDs and the resultant environmental risks.Lastly,current limitations in knowledge along with future research perspectives in the field are also highlighted in this article.展开更多
The aim of the present paper was to check for the presence of cerebrovascular dystroglycan in vertebrates,because dystroglycan,which is localized in the vascular astroglial end-feet,has a pivotal function in glio-vasc...The aim of the present paper was to check for the presence of cerebrovascular dystroglycan in vertebrates,because dystroglycan,which is localized in the vascular astroglial end-feet,has a pivotal function in glio-vascular connections.In mammalian brains,the immunoreactivity ofβ-dystroglycan subunit delineates the vessels.The results of the present study demonstrate similar patterns in other vertebrates,except for anurans and the teleost groups Ostariophysi and Euteleostei.In this study,we investigated 1 or 2 representative species of the main groups of Chondrichthyes,teleost and non-teleost ray-finned fishes,urodeles,anurans,and reptiles.We also investigated 5 mammalian and 3 bird species.Animals were obtained from breeders or fishermen.The presence ofβ-dystroglycan was investigated immunohistochemically in free-floating sections.Pre-embedding electron microscopical immunohistochemistry on Heterodontus japonicus shark brains demonstrated that in Elasmobranchii,β-dystroglycan is also localized in the perivascular glial end-feet despite the different construction of their blood-brain barrier.The results indicated that the cerebrovascularβ-dystroglycan immunoreactivity disappeared separately in anurans,and in teleosts,in the latter group before its division to Ostariophysi and Euteleostei.Immunohistochemistry in muscles and western blots from brain homogenates,however,detected the presence ofβ-dystroglycan,even in anurans and all teleosts.A possible explanation is that in the glial end-feet,β-dystroglycan is masked in these animals,or disappeared during adaptation to the freshwater habitat.展开更多
Gonadal soma-derived factor(Gsdf)is a member of the transforming growth factor beta(TGF-β)superfamily and a teleost-specific gene.Early studies suggested that Gsdf promotes spermatogonial proliferation;however recent...Gonadal soma-derived factor(Gsdf)is a member of the transforming growth factor beta(TGF-β)superfamily and a teleost-specific gene.Early studies suggested that Gsdf promotes spermatogonial proliferation;however recent reports have shed light on its role in sex differentiation based on expression profiles and gain-and loss-of-function studies.This paper discusses the involvement of Gsdf in gonadal sex differentiation and sex changes in teleosts.展开更多
Regenerative capacity of the central nervous system(CNS)is unevenly distributed among vertebrates.While most mammalian species including humans elicit limited repair following CNS injury or disease,highly regenerative...Regenerative capacity of the central nervous system(CNS)is unevenly distributed among vertebrates.While most mammalian species including humans elicit limited repair following CNS injury or disease,highly regenerative vertebrates including urodele amphibians and teleost fish spontaneously reverse CNS damage.Teletost zebrafish(danio rerio)are tropical freshwater fish that proved to be an excellent vertebrate model of successful CNS regeneration.Differential neuronal,glial,and immune injury responses underlie disparate injury outcomes between highly regenerative zebrafish and poorly regenerative mammals.This article describes complications associated with neuronal repair following spinal cord injury(SCI)in poorly regenerative mammals and highlights intersecting modes of plasticity and regeneration in highly regenerative zebrafish(Figures 1 and 2).Comparative approaches evaluating immunoglial SCI responses were recently reviewed elsewhere(Reyes and Mokalled,2024).展开更多
Among vertebrates,teleosts display a wide array of sex determination and differentiation mechanisms ranging from chromosomal sex determination on one end of the spectrum to environmental sex determination on the other...Among vertebrates,teleosts display a wide array of sex determination and differentiation mechanisms ranging from chromosomal sex determination on one end of the spectrum to environmental sex determination on the other end.However,the interplay of both these mechanisms is also not uncommon.Several gonochoristic fishes exhibit gonadal plasticity often resulting in sex reversal.The major manipulation of sex differentiation in teleost is affected by sex steroids.In this context,the increasing contamination of aquatic ecosystems by estrogen-like compounds,commonly known as xenoestrogens,is of major concern.This often leads to deleterious effects on the reproductive success of fish and thereby adversely impacts aquatic biodiversity.In the present review,we have focused on impact of xenoestrogen at different levels of the reproductive system influencing not only gonadal differentiation in teleosts but also their reproductive functions.The review would also explore the mitigation strategies and regulations in place for aquatic xenoestrogen management.展开更多
Intestinal inflammation is a common challenge in intensive aquaculture,yet its pathogenesis remains unclear.While interleukin 22(IL-22)is recognized as a critical regulator of cellular homeostasis during inflammation ...Intestinal inflammation is a common challenge in intensive aquaculture,yet its pathogenesis remains unclear.While interleukin 22(IL-22)is recognized as a critical regulator of cellular homeostasis during inflammation in higher vertebrates,its roles in fish are not well understood.This study established hypoxia-induced models in intestinal tissues and primary intestinal epithelial cells of yellow catfish to investigate the involvement of IL-22 in maintaining intestinal homeostasis.Results revealed that Pelteobagrus fulvidraco IL-22(Pf_IL-22)was abundantly expressed in mucosal tissues,with the highest levels in the gill and intestine.Hypoxia induced pronounced intestinal injury,characterized by loosening of the lamina propria and extensive vacuolization,while activating hypoxia-inducible factor(HIF)signaling and markedly up-regulating IL-22 expression.IL-22 levels peaked at 24 h post-hypoxia,suggesting a role in early immune responses.Recombinant Pf_IL-22 also induced transcription of pro-inflammatory mediators,including IL-1βand tumor necrosis factorα(TNF-α),in primary intestinal epithelial cells,indicating a dual regulatory function in balancing protection and inflammation.Mechanistic analyses revealed that HIF-1αdirectly interacted with a hypoxia response element within the IL-22 promoter to drive transcription,as confirmed by dual-luciferase assays,electrophoretic mobility-shift assays,and HIF-1αknockdown.Silencing Pf_IL-22 significantly suppressed Th17 cell differentiation pathways,demonstrating its role in shaping downstream immune responses.These findings establish the HIF-1α/IL-22 axis as a key regulatory pathway modulating immune responses and alleviating intestinal inflammation,providing a basis for developing IL-22-targeted immunotherapies and selective breeding strategies in aquaculture.展开更多
Teleosts,the most diverse vertebrate group comprising over 30,000 species,exhibit the most complex sex determination systems and mechanisms among vertebrates.With the increasing availability of sequenced and assembled...Teleosts,the most diverse vertebrate group comprising over 30,000 species,exhibit the most complex sex determination systems and mechanisms among vertebrates.With the increasing availability of sequenced and assembled fish genomes,numerous sex-determining genes(SDGs)have been successfully identified.Despite the diversity of SDGs discovered in teleosts,members of the TGF-βsuperfamily are frequently and independently recruited as SDGs across divergent fish lineages.Of over 150 teleost species with identified SDGs,approximately 60%have recruited TGF-βsuperfamily members as their SDGs.Within the species utilizing TGF-βmembers as SDGs,85%use homologs of anti-Müllerian hormone(amh)and its dedicated type II receptor(amhr2)as SDGs.To date,34 teleost species have been documented to utilize amh and 43 utilize amhr2 homologs as SDGs respectively.This selection bias underscores amh/amhr2 as the current'star players'among identified teleost SDGs.However,the reasons behind the recurrent recruitment of amh/amhr2 as SDGs,along with their downstream signaling pathways and molecular mechanisms governing teleost sex determination,remain unclear.Here,we systematically summarize recent advances in understanding the recruitment of amh/amhr2 as SDGs in teleosts.We propose that this preference may stem from functional redundancy,single-copy genomic architecture,ligand-receptor binding specificity and high affinity regulatory capacity in germ cell proliferation,as well as differentiation and extensive crosstalk with downstream male and female sex determination pathways.Future research should focus on the following aspects:elucidating the specificity and conservation of components in the Amh/Amhr2 signaling pathway,systematically identifying its downstream target genes and regulatory networks,and thoroughly investigating the evolutionary driving mechanisms behind its frequent recruitment as SDG.This review enhances mechanistic insights into the repeated co-option of amh/amhr2 as SDGs and advances the exploration of their signaling cascades and molecular networks in teleost sex determination.展开更多
This study examined the effect of underground water on reproduction- and growth-related hormones in blue gourami males under non-reproductive and reproductive conditions. An increase in the percentage of males buildin...This study examined the effect of underground water on reproduction- and growth-related hormones in blue gourami males under non-reproductive and reproductive conditions. An increase in the percentage of males building nests under the highest percentage of underground water were compared to fish that maintained a lower percentage of underground water in the first two days. The % Gonado-somatic index (GSI) of males building nests was higher than non- reproductively active males in water containing the lowest concentration of underground water. In non- reproductively active males, brain gonadotropin releasing hormone 1 (GnRH1) and pituitary β subunit of gonadotropins (GtHs) and prolactin (PRL) mRNA levels were significantly higher in males maintained in underground water. In reproductively active males, mRNA levels of brain GnRH1, gonadotropin releasing hormone 3 (GnRH3) and pituitary PRL mRNA levels were significantly higher than males maintained in underground water. Thus, it is suggested that underground water with high salinity and conductivity levels affects the gene expression of repro- duction-related hormones;in reproductively active males, it shortened the duration of nest-building by blue gourami males.展开更多
AIM To study the cell types,localization,distribution density and morphology of APUDcells in the intestinal mucosa of stomachlessteleost fishes.METHOD By using the peroxidase-antiperoxidase complex(PAP)immunocytochemi...AIM To study the cell types,localization,distribution density and morphology of APUDcells in the intestinal mucosa of stomachlessteleost fishes.METHOD By using the peroxidase-antiperoxidase complex(PAP)immunocytochemical staining technique theidentification,localization and morphology ofimmunoreactive(IR)endocrine cells seattered inthe intestinal mucosa of grass carp(Cyenopharyngodon idellus),black carp(Mylopharyngodon piceus)and common carp(Cyprinus carpio)were investigated with 20kinds of antisera prepared against mammalianpeptide hormones of APUD cells,and likewise byusing avidin-biotin-peroxidase complex(ABC)method those of silver carp(Hypophthalmichthys molitrix),bighead(Aristichthys nobilis),silver crucian carp(Carassius gibelio)and bluntnose black bream(Megalobrama amblyocephala)were alsostudied with 5 different antisera.Thereplacement of the first antiserum by phosphatebuffered saline(PBS)was employed as a control.IR endocrine cells were counted with asquare-mesh ocular micrometer from 10 fieldsselected randomly in every section of each partof the intestine specimen.The average numberof IR endocrine cells per mm2 was counted toquantify their distribution density.RESULT Gastrin(GAS)-,Gastric inhibitorypeptide(GIP)-,glucagon(GLU)-,glucagon-likeimmunoreactants(GLI)-,bovine pancreaticpolypeptide(BPP)-,leucine-enkephalin(ENK)-and substance P(SP)-IR endocrine cells werefound in the gut of grass carp,black carp andcommon carp,and somatostatin(SOM)-IRendocrine cells were only seen in common carp.GAS-,GIP-and GLU-IR endocrine cells werefound in the intestinal mucosa of silver carp,bighead,silver crucian carp and bluntnose blackbream.Most of IR endocrine cells had the higherdistribution density in the foregut and midgut,and were longer in shape.They had a long apicalcytoplasmic process extended to the gut lumenand a basal process extended to adjacent cellsor basement membrane and touched with it.Sometimes,the basal cytoplasmic processformed an enlarged synapse-like structure in thecontiguous part with basement membrane.Thisphenomenon provided new morphologicalevidence for neuroendocrine and paracrinesecretory function of these enteroendocrinecells.CONCLUTION At least 8 kinds of IR endocrinecells were found in the gut of stomachlessteleost species for the first time in China.TheseIR endocrine cells scattering in the gut mucosabelong to the APUD system.Among them,thehormones secreted by SP-,ENK-,SOM-and GLU-IR endocrine cells belong to the peptides of dualdistribution in the brain and gut.This providednew evidence for the concept of brain-gutpeptide.According to the cell types,distribution density,morphologicalcharacteristics and variety in shape of APUDcells in the gut of stomachless teleost fishes,itis deemed that the digestive tract of fishes isalso an endocrine organ of great importance andcomplexity.展开更多
Macrophages exist in most tissues and play a variety of functions in vertebrates.Teleost fish species are found in most aquatic environments throughout the world and are quite diverse for a group of vertebrate animals...Macrophages exist in most tissues and play a variety of functions in vertebrates.Teleost fish species are found in most aquatic environments throughout the world and are quite diverse for a group of vertebrate animals.Due to whole genome duplication and en vironme ntal adaptati on,teleost monocytes/macrophages possess a variety of different functions and modulations compared with those of mammals.A deeper understanding of teleost monocytes/macrophages in the immune system will not only help develop teleost-specific methods of disease prevention but will also help improve our understanding of the various immune mechanisms in mammals.In this review,we summarize the differences in polarizati on and phagocytosis of teleost and mammalian macrophages to improve our understanding of the various immune mechanisms in vertebrates.展开更多
Several mammalian animal models of traumatic brain injury have been used, mostly rodents. However, reparative mechanisms in mammalian brain are very limited, and newly formed neurons do not survive for long time. The ...Several mammalian animal models of traumatic brain injury have been used, mostly rodents. However, reparative mechanisms in mammalian brain are very limited, and newly formed neurons do not survive for long time. The brain of adult zebrafish, a teleost fish widely used as vertebrate model, possesses high regenerative properties after injury due to the presence of numerous stem cells niches. The ventricular lining of the zebrafish dorsal telencephalon is the most studied neuronal stem cell niche because its dorso-lateral zone is considered the equivalent to the hippocampus of mammals which contains one of the two constitutive neurogenic niches of mammals. To mimic TBI, stab wound in the dorso-lateral telencephalon of zebrafish was used in studies devoted to fish regenerative properties. Brain-derived neurotrophic factor, which is known to play key roles in the repair process after traumatic brain lesions, persists around the lesioned area of injured telencephalon of adult zebrafish. These results are extensively compared to reparative processes in rodent brain. Considering the complete repair of the damaged area in fish, it could be tempting to consider brain-derived neurotrophic factor as a factor contributing to create a permissive environment that enables the establishment of new neuronal population in damaged brain.展开更多
Insulin is a key hormone for the regulation of metabolism in vertebrates.Insulin is produced by pancreatic islet cells in response to elevated glucose levels and leads to the uptake of glucose by tissues such as liver...Insulin is a key hormone for the regulation of metabolism in vertebrates.Insulin is produced by pancreatic islet cells in response to elevated glucose levels and leads to the uptake of glucose by tissues such as liver and adipose tissue to store energy.Insulin also has additional functions in regulating development.Previous work has shown that the proglucagon gene,which encodes hormones counter regulating insulin,is duplicated in teleost fish,and that the peptide hormones encoded by these genes have diversified in function.I sought to determine whether similar processes have occurred to insulin genes in these species.Searches of fish genomes revealed an unexpected diversity of insulin genes.A triplication of the insulin gene occurred at the origin of teleost fish,however one of these three genes,insc,has been lost in most teleost fish lineages.The two other insulin genes,insa and insb,have been retained but show differing levels of selective constraint suggesting that they might have diversified in function.Intriguingly,a duplicate copy of the insa gene,which I named insab,is found in many fish.The coding sequenee encoded by insab genes is under weak selective constraint,with its predicted protein sequences losing their potential to be processed into a two-peptide hormone.However,these sequences have retained perfectly conserved cystine residues,suggesting that they maintain insulin's three-dimensional structure and therefore might modulate the processing and secretion of insulin produced by the other genes.展开更多
Within the last several decades,the scientific community has made substantial progress in elucidating the complex pathophysiology underlying spinal cord injury.However,despite the many advances using conventional mamm...Within the last several decades,the scientific community has made substantial progress in elucidating the complex pathophysiology underlying spinal cord injury.However,despite the many advances using conventional mammalian models,both cellular and axonal regeneration following spinal cord injury have remained out of reach.In this sense,turning to non-mammalian,regenerative species presents a unique opportunity to identify pro-regenerative cues and chara cterize a spinal cord microenvironment permissive to re-growth.Among the signaling pathways hypothesized to be dysregulated during spinal cord injury is the purinergic signaling system.In addition to its well-known role as energy currency in cells,ATP and its metabolites are small molecule neurotransmitte rs that mediate many diverse cellular processes within the central nervous system.While our unde rstanding of the roles of the purinergic system following spinal cord injury is limited,this signaling pathway has been implicated in all injury-induced secondary processes,including cellular death,inflammation,reactive gliosis,and neural regeneration.Given that the purinergic system is also evolutionarily conserved between mammalian and non-mammalian species,comparisons of these roles may provide important insights into conditions responsible for recovery success.Here,we compare the secondary processes between key model species and the influence of purinergic signaling in each context.As our understanding of this signaling system and pro-regenerative conditions continues to evolve,so does the potential for the development of novel therapeutic interventions for spinal cord injury.展开更多
During adaptation to different habitat types, both morphological and behavioral traits can undergo divergent selection. Males often fight for status in dominance hierarchies and rank positions predict reproductive suc...During adaptation to different habitat types, both morphological and behavioral traits can undergo divergent selection. Males often fight for status in dominance hierarchies and rank positions predict reproductive success. Ecotypes with reduced fighting abilities should have low reproductive success when migrating into habitats that harbor ecotypes with superior fighting abilities. Livebearing fishes in the Poecilia mexicana-species complex inhabit not only regular freshwater environments, but also independently colonized sulfidic （H2S-containing） habitats in three river drainages. In the current study, we found fighting intensities in staged contests to be considerably lower in some but not all sulfidic surface ecotypes and the sulfidic cave ecotype compared with populations from non-sulfidic surface sites. This is perhaps due to selection imposed by H2S, which hampers oxygen uptake and transport, as well as cellular respiration. Furthermore, migrants from sulfidic habitats may lose fights even if they do not show overall reduced aggressiveness, as phys- iological performance is likely to be challenged in the non-sulfidic environment to which they are not adapted. To test this hypothesis, we simulated migration of H2S-adapted males into H2S-free waters, as well as H2S-adapted cave-dwelling males into sulfidic surface waters. We found that intruders established dominance less often than resident males, independent of whether or not they showed reduced aggressiveness overall. Our study shows that divergent evolution of male aggressive behavior may also contribute to the maintenance of genetic differentiation in this system and we call for more careful evaluation of male fighting abilities in studies on ecological speciation.展开更多
Within the last several decades,the scientific community has made substantial progress in elucidating the complex pathophysiology underlying spinal cord injury.However,despite the many advances using conventional mamm...Within the last several decades,the scientific community has made substantial progress in elucidating the complex pathophysiology underlying spinal cord injury.However,despite the many advances using conventional mammalian models,both cellular and axonal regeneration following spinal cord injury have remained out of reach.In this sense,turning to non-mammalian,regenerative species presents a unique opportunity to identify pro-regenerative cues and characterize a spinal cord microenvironment permissive to re-growth.Among the signaling pathways hypothesized to be dysregulated during spinal cord injury is the purinergic signaling system.In addition to its well-known role as energy currency in cells,ATP and its metabolites are small molecule neurotransmitters that mediate many diverse cellular processes within the central nervous system.While our understanding of the roles of the purinergic system following spinal cord injury is limited,this signaling pathway has been implicated in all injury-induced secondary processes,including cellular death,inflammation,reactive gliosis,and neural regeneration.Given that the purinergic system is also evolutionarily conserved between mammalian and non-mammalian species,comparisons of these roles may provide important insights into conditions responsible for recovery success.Here,we compare the secondary processes between key model species and the influence of purinergic signaling in each context.As our understanding of this signaling system and pro-regenerative conditions continues to evolve,so does the potential for the development of novel therapeutic interventions for spinal cord injury.展开更多
Horizontal gene transfer(HGT)is a common occurrence across all domains of life.However,most HGT events were reported between single-celled organisms or parasites and hosts(Van Etten and Bhattacharya 2020).A type II an...Horizontal gene transfer(HGT)is a common occurrence across all domains of life.However,most HGT events were reported between single-celled organisms or parasites and hosts(Van Etten and Bhattacharya 2020).A type II antifreeze protein(AFP)gene was the first and sole evidence of HGT direct vertebrate-to-vertebrate DNA transmission.AFP is only found in 3 widely separated branches of teleost fishes(herring,sea raven,and smelts),sharing amino acid similarity up to 80%(Graham et al.2008).展开更多
基金supported by the National Natural Science Foundation of China (32473194)Natural Science Foundation of Zhejiang Province (LY23C190002)+1 种基金Natural Science Foundation of Ningbo City (202003N4011)One Health Interdisciplinary Research Project of Ningbo University (HZ202201)。
文摘NLRP3 inflammasome activation is pivotal for cytokine secretion and pyroptosis in response to diverse stimuli,playing a crucial role in innate immunity.While extensively studied in mammals,the regulatory mechanisms governing NLRP3 activation in non-mammalian vertebrates remain largely unexplored.Teleosts,as basal vertebrates,represent an ideal model for exploring the evolutionary trajectory of inflammasome regulation.In this study,ABE assays,confocal microscopy,and biochemical analyses were applied to systematically characterize the mechanisms underlying NLRP3 inflammasome in teleosts,using large yellow croakers(Larimichthys crocea,Lc)and zebrafish(Danio rerio,Dr)as representative models.Our findings revealed a previously unrecognized palmitoylation-dependent regulatory mechanism essential for teleost NLRP3 activation.Specifically,zDHHC18-mediated palmitoylation at a teleost-specific cysteine residue(C946 in LcNLRP3,C1037 in DrNLRP3)was required for the translocation of NLRP3 to the dispersed trans-Golgi network,facilitating its subsequent recruitment to the microtubule-organizing center.This membrane trafficking was crucial for inflammasome assembly and downstream inflammatory responses.These findings provide new insights into the distinct regulatory mechanisms of NLRP3 activation in teleosts,highlighting an evolutionary divergence that contributes to innate immunity adaptation in early vertebrates.
基金The Fund of Southern Marine Science and Engineering Guangdong Laboratory(Zhanjiang)under contract No.ZJW-2023-01the Guangdong Basic and Applied Basic Research Foundation under contract Nos 2023A1515010576 and 2024A1515012859the Marine Youth Talent Project of Zhanjiang under contract No.2023E0006.
文摘Sex-biased microRNAs(miRNAs)influence gonadal development in fish by directly targeting genes associated with estrogen production pathways.WW domain-binding protein 2(WBP2)functions as a crucial transcriptional co-activator of the estrogen and progesterone receptors(PGR).This study investigates the direct modulation of a sex-biased miR-133b on wbp2 and its regulatory role in gonadal development in fish,the greater amberjack(Seriola dumerili).Using dual-luciferase reporter assays,we demonstrate that wbp2 is a direct target of miR-133b,with miR-133b-3p binding to the 3'untranslated region(3'UTR)of wbp2.In vitro,miR-133b mimic significantly downregulate wbp2 expression,while the miR-133b inhibitor increase wbp2 levels.Consistently,in vivo,wbp2 expression is upregulated following antagomir-133b treatment and downregulated following agomir-133b.RNA fluorescence in situ hybridization(RNA-FISH)results reveal miR-133b and wbp2 co-localization in ovarian interstitial cells.Notably,phylogenetic analysis indicates that miR-133b-3p and wbp2 are highly conserved among bony fish species.Additionally,dual-luciferase assays in other bony fish species including Oreochromis niloticus and Danio rerio also confirm the targeting effect of miR-133b-3p on wbp2,suggesting that this regulatory mechanism is conserved across bony fish.This research provides a theoretical foundation for further exploration of non-coding RNA-mediated regulation in gonadal development in teleost.
基金the National Natural Science Foundation of China,No.39470554
文摘AIM To identify the type localization andmorphology of APUD endocrine cells in thegastroenteropancreatic(GEP)system ofstomach-containing teleosts,and study APUDendocrine system in the stomach,intestine andpancreas of fish species.METHODS Two kinds of immunocytochemical(ICC)techniques of the streptavidin biotin-peroxidase complex(SABC)and streptavidin-peroxidase(S-P)method were used.Theidentification,localization and morphology ofAPUD endocrine cells scattered in the mucosa ofdigestive tract,intermuscular nerve plexus andglandular body of northern snakehead(Channaargus),ricefield eel(Monopterus albus),yellow catfish(Pelteobagrus fulvidraco),mandarinfish(Siniperca chuatsi),largemouthbass(Micropterus salmoides),orientalsheatfish(Silurus asotus),freshwater pomfret(Colossoma brachypomum)and nile tilapia(Tilapia nilotica)were investigated with 8 kindsof antisera.RESULTS The positive reaction of 5-hydroxytryptamine(5-HT)immunoreactiveendocrine(IRE)cells was found in the digestive tract and glandular body of 8 fish species indifferent degree.Only a few gastrin(GAS)-IREcells were seen in C.argus,M.albus and P.fulvidraco.Glucagon(GLU)-IRE cells were notfound in the digestive tract and glandular bodybut existed in pancreatic island of most fishspecies.The positive reaction of growthhormone(GH)-IRE cells was found only inpancreatic island of S.Chuatsi and S.Asotus,no positive reaction in the other 6 fish species.Somatostatin(SOM)-,calcitonin(CAL)-,neurofilament(NF)-and insulin(INS)-IRE cellsin the stomach,intestine and pancreas of 8 kindsof fish were different in distribution and types.The distribution of all 8 APUD cells was the mostin gastrointestinal epithelium mucosa and then indigestive glands.The positive reaction of SOM-and 5-HT-IRE cells was found in intermuscularnerve plexus of intestine of P.fulvidraco andS.chuatsi.Only GH-IRE cells were denselyscattered in the pancreatic islands of S.chuatsiand S.asotus,and odd distribution in thepancreas of S.asotus,SOM-IRE cells weredistributed in the pancreatic islands of S.asotus,C.Brachypomum and T.nilotica.There were INS-IRE cells in the pancreaticislands of S.chuatsi and S.asolus.Eightkinds of APUD cells had longer cell body andcytoplasmic process when they were located inthe gastrointestinal epithelium,and had shortercell body and cytoplasmic process in the gastricgland,and irregular shape in the esophagus andpancreatic island.CONCLUSION Eight kinds of IRE cells were identified in the GEP system of stomach-containing teleosts. These endocrine cells were scattered in gastrointestinal mucosa, intermuscular nerve plexus, gland body, pancreatic gland and islands under APUD system. CAL- and GH-IRE cells in the pancreatic islands of fishes showed functional diversity for these two hormones. Their morphological feature provides evidence of endocrine-paracrine and endocrine-exocrine acting mode. This research can morphologically prove that the GEP endocrine system of fish ( the lowest vertebrate) is almost the same as of mammal and human.
基金supported by the National Natural Science Foundation of China (32373164)。
文摘Toll-like receptors(TLRs) sit at the top of the immune system pyramid.They form a paramount family of immune sentinels capable of sensing diverse microbe-associated molecular patterns(MAPMs),danger/damage-associated molecular patterns(DAMPs),and other signals.These perceptions trigger immediate innate immunity and instruct subsequent adaptive immunity.TLRs are highly glycosylated type I transmembrane glycoproteins that share a conserved tripartite domain architecture(LRR,TM and TIR domains),classified into six subfamilies(TLR1,TLR3,TLR4,TLR5,TLR7,TLR11) in vertebrates.Upon ligand engagement,TLRs form homodimers or heterodimers to activate immune responses via SMOCs,orchestrated by intrinsic and pathogen-directed negative regulators,glycosylation modification,etc.TLR signaling culminates in the production of inflammatory cytokines,interferons,inflammasomes,immune cell activation,apoptosis,etc.Teleosts,as the largest and most diverse group among the extant vertebrates,manifest important economic value and are crucial for understanding the evolution of vertebrate immunity.To date,teleosts contain 20 TLRs(TLR1–5,TLR7–9,TLR13,TLR14,TLR18–23,TLR25– 28) with expansions and losses in different species,and most of them possess more or less variants.Almost all teleostean TLRs localize in organelles,such as endosomes and lysosomes,sensing not only pathogens and DAMPs but also trophic factors and environmental stresses(hypoxia,temperature,microplastics,etc.).Most ligands for TLRs remain undetermined in teleosts.The adaptors consist of My D88,TIRAP,TRIF,SARM1,BCAP and SCIMP,but without TRAM;however,half of the corresponding relationships between TLRs and adaptors remain unknown in teleosts.Neofunctionalization often emerges during evolution in teleostean TLRs.Here,a systematic review of TLR signaling in teleosts,from the perspective of comparative immunology,presents the current understanding of the functions and mechanisms of teleosts.Additionally,it provides strong evidence of a divergent TLR signaling repertoire with the species-specific variation among teleosts.These are expected to benefit novel adjuvants,aquaculture,fish immunology,and comparative immunology.
基金SK and PS are grateful to the University of Hyderabad for Non-NET fellowships.NA is thankful to the Junior Research Fellowship support by a grant-in-aid(BT/PR15748/AAQ/3/803/2016)from the Department of Biotechnology(DBT)India awarded to BS.BS is also a recipient of TATA innovation fellowship(BT/HRD/35/01/02/2013)from DBT,India(during the years:2014-2019)which is acknowledged.
文摘Endocrine disruptors(EDs)are synthetic or natural chemical molecules occurring in environment that have the potential to impart adverse effects on homeostasis of endocrine axis leading to neurological,developmental,immunological and reproductive disarray at organismal level.A wide range of structurally diverse EDs such as,sex-steroid hormone mimics,pesticides and fertilizers,prevail in the environment originating from waste of industries,pharmaceutics,sewage treatment plants and agriculture.In addition,some metals,such as Cu,Hg and Zn,have endocrine disrupting potency in their metallic as well as synthesized nano-particulate forms.There is an increasing concern in research for the plausible threat posed by EDs that can disrupt the endocrine system in aquatic fauna as these compounds are frequently discharged or run-off into water stream.Fishes are well known bio-indicators to understand toxicity of EDs as they are vulnerable to endocrine disruption.Furthermore,EDs have the potential to affect fish-feeding higher vertebrates including mammals and subsequently human,as they make their way up on the food web pyramid due to biomagnification.In light of this,several observations suggesting adverse effects of EDs and the mechanism contributing to endocrine disruption in fish are discussed extensively in this review.This article highlights the necessity to choose a credible model for assessing the toxic effects exerted by EDs.Furthermore,the toxic effects of EDs will be comprehensively reviewed with reference to sexual plasticity,neuroendocrine mechanisms,thyroid and immune modulation,gonadal development and maturation as well as changes in transcriptome/genome profile using fish models to imply ED-induced aquatic pollution in a larger perspective.For decades now,studies on EDs have challenged traditional concepts in toxicology to develop new molecular markers to improve methodologies and to assess the ecological risks associated with field conditions.In this regard,it is imperative to highlight the development of modern diagnostic tools including biosensors to monitor the inadvertent usage of EDs and the resultant environmental risks.Lastly,current limitations in knowledge along with future research perspectives in the field are also highlighted in this article.
文摘The aim of the present paper was to check for the presence of cerebrovascular dystroglycan in vertebrates,because dystroglycan,which is localized in the vascular astroglial end-feet,has a pivotal function in glio-vascular connections.In mammalian brains,the immunoreactivity ofβ-dystroglycan subunit delineates the vessels.The results of the present study demonstrate similar patterns in other vertebrates,except for anurans and the teleost groups Ostariophysi and Euteleostei.In this study,we investigated 1 or 2 representative species of the main groups of Chondrichthyes,teleost and non-teleost ray-finned fishes,urodeles,anurans,and reptiles.We also investigated 5 mammalian and 3 bird species.Animals were obtained from breeders or fishermen.The presence ofβ-dystroglycan was investigated immunohistochemically in free-floating sections.Pre-embedding electron microscopical immunohistochemistry on Heterodontus japonicus shark brains demonstrated that in Elasmobranchii,β-dystroglycan is also localized in the perivascular glial end-feet despite the different construction of their blood-brain barrier.The results indicated that the cerebrovascularβ-dystroglycan immunoreactivity disappeared separately in anurans,and in teleosts,in the latter group before its division to Ostariophysi and Euteleostei.Immunohistochemistry in muscles and western blots from brain homogenates,however,detected the presence ofβ-dystroglycan,even in anurans and all teleosts.A possible explanation is that in the glial end-feet,β-dystroglycan is masked in these animals,or disappeared during adaptation to the freshwater habitat.
基金supported by UK-Japan Research Collaboration Grants from the Ministry of the Environment,Japan,and JSPS KAKENHI grant No.18H02281 awarded to T.K.
文摘Gonadal soma-derived factor(Gsdf)is a member of the transforming growth factor beta(TGF-β)superfamily and a teleost-specific gene.Early studies suggested that Gsdf promotes spermatogonial proliferation;however recent reports have shed light on its role in sex differentiation based on expression profiles and gain-and loss-of-function studies.This paper discusses the involvement of Gsdf in gonadal sex differentiation and sex changes in teleosts.
文摘Regenerative capacity of the central nervous system(CNS)is unevenly distributed among vertebrates.While most mammalian species including humans elicit limited repair following CNS injury or disease,highly regenerative vertebrates including urodele amphibians and teleost fish spontaneously reverse CNS damage.Teletost zebrafish(danio rerio)are tropical freshwater fish that proved to be an excellent vertebrate model of successful CNS regeneration.Differential neuronal,glial,and immune injury responses underlie disparate injury outcomes between highly regenerative zebrafish and poorly regenerative mammals.This article describes complications associated with neuronal repair following spinal cord injury(SCI)in poorly regenerative mammals and highlights intersecting modes of plasticity and regeneration in highly regenerative zebrafish(Figures 1 and 2).Comparative approaches evaluating immunoglial SCI responses were recently reviewed elsewhere(Reyes and Mokalled,2024).
基金Minor Research Grant,Institution of Eminence(IoE/FRP/LS/2020/27)by University of Delhi.
文摘Among vertebrates,teleosts display a wide array of sex determination and differentiation mechanisms ranging from chromosomal sex determination on one end of the spectrum to environmental sex determination on the other end.However,the interplay of both these mechanisms is also not uncommon.Several gonochoristic fishes exhibit gonadal plasticity often resulting in sex reversal.The major manipulation of sex differentiation in teleost is affected by sex steroids.In this context,the increasing contamination of aquatic ecosystems by estrogen-like compounds,commonly known as xenoestrogens,is of major concern.This often leads to deleterious effects on the reproductive success of fish and thereby adversely impacts aquatic biodiversity.In the present review,we have focused on impact of xenoestrogen at different levels of the reproductive system influencing not only gonadal differentiation in teleosts but also their reproductive functions.The review would also explore the mitigation strategies and regulations in place for aquatic xenoestrogen management.
基金supported by the National Natural Science Foundation of China(32102760)“JBGS”Project of Seed Industry Revitalization in Jiangsu Province(JBGS(2021)034)+1 种基金Creation Project of Major New Species of Agriculture in Jiangsu Province(PZCZ201742)Key Laboratory of Healthy Freshwater Aquaculture,Ministry of Agriculture and Rural Affairs,Key Laboratory of Freshwater Aquaculture Genetic and Breeding of Zhejiang Province,Zhejiang Institute of Freshwater Fisheries,Huzhou 313001(ZJK202404)。
文摘Intestinal inflammation is a common challenge in intensive aquaculture,yet its pathogenesis remains unclear.While interleukin 22(IL-22)is recognized as a critical regulator of cellular homeostasis during inflammation in higher vertebrates,its roles in fish are not well understood.This study established hypoxia-induced models in intestinal tissues and primary intestinal epithelial cells of yellow catfish to investigate the involvement of IL-22 in maintaining intestinal homeostasis.Results revealed that Pelteobagrus fulvidraco IL-22(Pf_IL-22)was abundantly expressed in mucosal tissues,with the highest levels in the gill and intestine.Hypoxia induced pronounced intestinal injury,characterized by loosening of the lamina propria and extensive vacuolization,while activating hypoxia-inducible factor(HIF)signaling and markedly up-regulating IL-22 expression.IL-22 levels peaked at 24 h post-hypoxia,suggesting a role in early immune responses.Recombinant Pf_IL-22 also induced transcription of pro-inflammatory mediators,including IL-1βand tumor necrosis factorα(TNF-α),in primary intestinal epithelial cells,indicating a dual regulatory function in balancing protection and inflammation.Mechanistic analyses revealed that HIF-1αdirectly interacted with a hypoxia response element within the IL-22 promoter to drive transcription,as confirmed by dual-luciferase assays,electrophoretic mobility-shift assays,and HIF-1αknockdown.Silencing Pf_IL-22 significantly suppressed Th17 cell differentiation pathways,demonstrating its role in shaping downstream immune responses.These findings establish the HIF-1α/IL-22 axis as a key regulatory pathway modulating immune responses and alleviating intestinal inflammation,providing a basis for developing IL-22-targeted immunotherapies and selective breeding strategies in aquaculture.
基金supported by the National Key Research and Development Program of China[grant number 2022YFD1201603]the National Natural Science Foundation of China[grant number 31861123001]Chongqing Fishery Technology Innovation Union[grant number CQFTIU202501-07].
文摘Teleosts,the most diverse vertebrate group comprising over 30,000 species,exhibit the most complex sex determination systems and mechanisms among vertebrates.With the increasing availability of sequenced and assembled fish genomes,numerous sex-determining genes(SDGs)have been successfully identified.Despite the diversity of SDGs discovered in teleosts,members of the TGF-βsuperfamily are frequently and independently recruited as SDGs across divergent fish lineages.Of over 150 teleost species with identified SDGs,approximately 60%have recruited TGF-βsuperfamily members as their SDGs.Within the species utilizing TGF-βmembers as SDGs,85%use homologs of anti-Müllerian hormone(amh)and its dedicated type II receptor(amhr2)as SDGs.To date,34 teleost species have been documented to utilize amh and 43 utilize amhr2 homologs as SDGs respectively.This selection bias underscores amh/amhr2 as the current'star players'among identified teleost SDGs.However,the reasons behind the recurrent recruitment of amh/amhr2 as SDGs,along with their downstream signaling pathways and molecular mechanisms governing teleost sex determination,remain unclear.Here,we systematically summarize recent advances in understanding the recruitment of amh/amhr2 as SDGs in teleosts.We propose that this preference may stem from functional redundancy,single-copy genomic architecture,ligand-receptor binding specificity and high affinity regulatory capacity in germ cell proliferation,as well as differentiation and extensive crosstalk with downstream male and female sex determination pathways.Future research should focus on the following aspects:elucidating the specificity and conservation of components in the Amh/Amhr2 signaling pathway,systematically identifying its downstream target genes and regulatory networks,and thoroughly investigating the evolutionary driving mechanisms behind its frequent recruitment as SDG.This review enhances mechanistic insights into the repeated co-option of amh/amhr2 as SDGs and advances the exploration of their signaling cascades and molecular networks in teleost sex determination.
文摘This study examined the effect of underground water on reproduction- and growth-related hormones in blue gourami males under non-reproductive and reproductive conditions. An increase in the percentage of males building nests under the highest percentage of underground water were compared to fish that maintained a lower percentage of underground water in the first two days. The % Gonado-somatic index (GSI) of males building nests was higher than non- reproductively active males in water containing the lowest concentration of underground water. In non- reproductively active males, brain gonadotropin releasing hormone 1 (GnRH1) and pituitary β subunit of gonadotropins (GtHs) and prolactin (PRL) mRNA levels were significantly higher in males maintained in underground water. In reproductively active males, mRNA levels of brain GnRH1, gonadotropin releasing hormone 3 (GnRH3) and pituitary PRL mRNA levels were significantly higher than males maintained in underground water. Thus, it is suggested that underground water with high salinity and conductivity levels affects the gene expression of repro- duction-related hormones;in reproductively active males, it shortened the duration of nest-building by blue gourami males.
基金the National Natural Science Foundation of China.No.39070666.
文摘AIM To study the cell types,localization,distribution density and morphology of APUDcells in the intestinal mucosa of stomachlessteleost fishes.METHOD By using the peroxidase-antiperoxidase complex(PAP)immunocytochemical staining technique theidentification,localization and morphology ofimmunoreactive(IR)endocrine cells seattered inthe intestinal mucosa of grass carp(Cyenopharyngodon idellus),black carp(Mylopharyngodon piceus)and common carp(Cyprinus carpio)were investigated with 20kinds of antisera prepared against mammalianpeptide hormones of APUD cells,and likewise byusing avidin-biotin-peroxidase complex(ABC)method those of silver carp(Hypophthalmichthys molitrix),bighead(Aristichthys nobilis),silver crucian carp(Carassius gibelio)and bluntnose black bream(Megalobrama amblyocephala)were alsostudied with 5 different antisera.Thereplacement of the first antiserum by phosphatebuffered saline(PBS)was employed as a control.IR endocrine cells were counted with asquare-mesh ocular micrometer from 10 fieldsselected randomly in every section of each partof the intestine specimen.The average numberof IR endocrine cells per mm2 was counted toquantify their distribution density.RESULT Gastrin(GAS)-,Gastric inhibitorypeptide(GIP)-,glucagon(GLU)-,glucagon-likeimmunoreactants(GLI)-,bovine pancreaticpolypeptide(BPP)-,leucine-enkephalin(ENK)-and substance P(SP)-IR endocrine cells werefound in the gut of grass carp,black carp andcommon carp,and somatostatin(SOM)-IRendocrine cells were only seen in common carp.GAS-,GIP-and GLU-IR endocrine cells werefound in the intestinal mucosa of silver carp,bighead,silver crucian carp and bluntnose blackbream.Most of IR endocrine cells had the higherdistribution density in the foregut and midgut,and were longer in shape.They had a long apicalcytoplasmic process extended to the gut lumenand a basal process extended to adjacent cellsor basement membrane and touched with it.Sometimes,the basal cytoplasmic processformed an enlarged synapse-like structure in thecontiguous part with basement membrane.Thisphenomenon provided new morphologicalevidence for neuroendocrine and paracrinesecretory function of these enteroendocrinecells.CONCLUTION At least 8 kinds of IR endocrinecells were found in the gut of stomachlessteleost species for the first time in China.TheseIR endocrine cells scattering in the gut mucosabelong to the APUD system.Among them,thehormones secreted by SP-,ENK-,SOM-and GLU-IR endocrine cells belong to the peptides of dualdistribution in the brain and gut.This providednew evidence for the concept of brain-gutpeptide.According to the cell types,distribution density,morphologicalcharacteristics and variety in shape of APUDcells in the gut of stomachless teleost fishes,itis deemed that the digestive tract of fishes isalso an endocrine organ of great importance andcomplexity.
基金supported by the National Natural Science Foundation of China(31772876,41776151)Natural Science Foundation of Zhejiang Province(LZ18C190001,LR18C040001)+1 种基金Scientific Innovation Team Project of Ningbo(2015C110018)K.C.Wong Magna Fund in Ningbo University
文摘Macrophages exist in most tissues and play a variety of functions in vertebrates.Teleost fish species are found in most aquatic environments throughout the world and are quite diverse for a group of vertebrate animals.Due to whole genome duplication and en vironme ntal adaptati on,teleost monocytes/macrophages possess a variety of different functions and modulations compared with those of mammals.A deeper understanding of teleost monocytes/macrophages in the immune system will not only help develop teleost-specific methods of disease prevention but will also help improve our understanding of the various immune mechanisms in mammals.In this review,we summarize the differences in polarizati on and phagocytosis of teleost and mammalian macrophages to improve our understanding of the various immune mechanisms in vertebrates.
文摘Several mammalian animal models of traumatic brain injury have been used, mostly rodents. However, reparative mechanisms in mammalian brain are very limited, and newly formed neurons do not survive for long time. The brain of adult zebrafish, a teleost fish widely used as vertebrate model, possesses high regenerative properties after injury due to the presence of numerous stem cells niches. The ventricular lining of the zebrafish dorsal telencephalon is the most studied neuronal stem cell niche because its dorso-lateral zone is considered the equivalent to the hippocampus of mammals which contains one of the two constitutive neurogenic niches of mammals. To mimic TBI, stab wound in the dorso-lateral telencephalon of zebrafish was used in studies devoted to fish regenerative properties. Brain-derived neurotrophic factor, which is known to play key roles in the repair process after traumatic brain lesions, persists around the lesioned area of injured telencephalon of adult zebrafish. These results are extensively compared to reparative processes in rodent brain. Considering the complete repair of the damaged area in fish, it could be tempting to consider brain-derived neurotrophic factor as a factor contributing to create a permissive environment that enables the establishment of new neuronal population in damaged brain.
文摘Insulin is a key hormone for the regulation of metabolism in vertebrates.Insulin is produced by pancreatic islet cells in response to elevated glucose levels and leads to the uptake of glucose by tissues such as liver and adipose tissue to store energy.Insulin also has additional functions in regulating development.Previous work has shown that the proglucagon gene,which encodes hormones counter regulating insulin,is duplicated in teleost fish,and that the peptide hormones encoded by these genes have diversified in function.I sought to determine whether similar processes have occurred to insulin genes in these species.Searches of fish genomes revealed an unexpected diversity of insulin genes.A triplication of the insulin gene occurred at the origin of teleost fish,however one of these three genes,insc,has been lost in most teleost fish lineages.The two other insulin genes,insa and insb,have been retained but show differing levels of selective constraint suggesting that they might have diversified in function.Intriguingly,a duplicate copy of the insa gene,which I named insab,is found in many fish.The coding sequenee encoded by insab genes is under weak selective constraint,with its predicted protein sequences losing their potential to be processed into a two-peptide hormone.However,these sequences have retained perfectly conserved cystine residues,suggesting that they maintain insulin's three-dimensional structure and therefore might modulate the processing and secretion of insulin produced by the other genes.
基金a Natural Sciences and Engineering Research Council operating grant(RGPIN-2019-07062)。
文摘Within the last several decades,the scientific community has made substantial progress in elucidating the complex pathophysiology underlying spinal cord injury.However,despite the many advances using conventional mammalian models,both cellular and axonal regeneration following spinal cord injury have remained out of reach.In this sense,turning to non-mammalian,regenerative species presents a unique opportunity to identify pro-regenerative cues and chara cterize a spinal cord microenvironment permissive to re-growth.Among the signaling pathways hypothesized to be dysregulated during spinal cord injury is the purinergic signaling system.In addition to its well-known role as energy currency in cells,ATP and its metabolites are small molecule neurotransmitte rs that mediate many diverse cellular processes within the central nervous system.While our unde rstanding of the roles of the purinergic system following spinal cord injury is limited,this signaling pathway has been implicated in all injury-induced secondary processes,including cellular death,inflammation,reactive gliosis,and neural regeneration.Given that the purinergic system is also evolutionarily conserved between mammalian and non-mammalian species,comparisons of these roles may provide important insights into conditions responsible for recovery success.Here,we compare the secondary processes between key model species and the influence of purinergic signaling in each context.As our understanding of this signaling system and pro-regenerative conditions continues to evolve,so does the potential for the development of novel therapeutic interventions for spinal cord injury.
文摘During adaptation to different habitat types, both morphological and behavioral traits can undergo divergent selection. Males often fight for status in dominance hierarchies and rank positions predict reproductive success. Ecotypes with reduced fighting abilities should have low reproductive success when migrating into habitats that harbor ecotypes with superior fighting abilities. Livebearing fishes in the Poecilia mexicana-species complex inhabit not only regular freshwater environments, but also independently colonized sulfidic （H2S-containing） habitats in three river drainages. In the current study, we found fighting intensities in staged contests to be considerably lower in some but not all sulfidic surface ecotypes and the sulfidic cave ecotype compared with populations from non-sulfidic surface sites. This is perhaps due to selection imposed by H2S, which hampers oxygen uptake and transport, as well as cellular respiration. Furthermore, migrants from sulfidic habitats may lose fights even if they do not show overall reduced aggressiveness, as phys- iological performance is likely to be challenged in the non-sulfidic environment to which they are not adapted. To test this hypothesis, we simulated migration of H2S-adapted males into H2S-free waters, as well as H2S-adapted cave-dwelling males into sulfidic surface waters. We found that intruders established dominance less often than resident males, independent of whether or not they showed reduced aggressiveness overall. Our study shows that divergent evolution of male aggressive behavior may also contribute to the maintenance of genetic differentiation in this system and we call for more careful evaluation of male fighting abilities in studies on ecological speciation.
基金supported by a Natural Sciences and Engineering Research Council operating grant(RGPIN-2019-07062).
文摘Within the last several decades,the scientific community has made substantial progress in elucidating the complex pathophysiology underlying spinal cord injury.However,despite the many advances using conventional mammalian models,both cellular and axonal regeneration following spinal cord injury have remained out of reach.In this sense,turning to non-mammalian,regenerative species presents a unique opportunity to identify pro-regenerative cues and characterize a spinal cord microenvironment permissive to re-growth.Among the signaling pathways hypothesized to be dysregulated during spinal cord injury is the purinergic signaling system.In addition to its well-known role as energy currency in cells,ATP and its metabolites are small molecule neurotransmitters that mediate many diverse cellular processes within the central nervous system.While our understanding of the roles of the purinergic system following spinal cord injury is limited,this signaling pathway has been implicated in all injury-induced secondary processes,including cellular death,inflammation,reactive gliosis,and neural regeneration.Given that the purinergic system is also evolutionarily conserved between mammalian and non-mammalian species,comparisons of these roles may provide important insights into conditions responsible for recovery success.Here,we compare the secondary processes between key model species and the influence of purinergic signaling in each context.As our understanding of this signaling system and pro-regenerative conditions continues to evolve,so does the potential for the development of novel therapeutic interventions for spinal cord injury.
基金supported by the National Key Research and Development Program of China(2017YFA0604904)the Zhejiang Provincial Natural Science Foundation of China(LR21D060003)to Z.H.
文摘Horizontal gene transfer(HGT)is a common occurrence across all domains of life.However,most HGT events were reported between single-celled organisms or parasites and hosts(Van Etten and Bhattacharya 2020).A type II antifreeze protein(AFP)gene was the first and sole evidence of HGT direct vertebrate-to-vertebrate DNA transmission.AFP is only found in 3 widely separated branches of teleost fishes(herring,sea raven,and smelts),sharing amino acid similarity up to 80%(Graham et al.2008).
