A twelve week experiment was conducted to compare the effects of diets with plant-based and animal-based ingredients on growth and gonad development of Clarias gariepinus. One hundred and 12 sub-adult C. gariepinus wi...A twelve week experiment was conducted to compare the effects of diets with plant-based and animal-based ingredients on growth and gonad development of Clarias gariepinus. One hundred and 12 sub-adult C. gariepinus with an average weight of 205 ×5.09 g, were stocked in six concrete tanks （9 × 4 × 2 m3） containing 20 fish each. Experiment had 3 replicates and animals fed daily at 5% body weights. There was no significant difference （P 〈 0.05） in proximate compositions of the two experimental feeds and controls. Fecundity, gonad weight and gonasomatic index were higher in fish fed diet 13 than A and C. Similarly, growth indices were higher in fish fed diet B than in A and C. Histology of gonads showed a faster development of oocytes of eggs in fish fed animal-based ingredients than plant-based and combined plant and animal diets. Although there were slight differences in growth parameters and gonad development in favor of feed with animal-based ingredients, plant-based feed compared favorably in the growth and gonad development of C. gariepinus. Plant-based ingredients are recommended on the basis of affordability and availability as substitute for animal-based ingredients in C. gariepinus feed.展开更多
The factor in the germline alpha(figla), as a member of the basic helix-loop-helix family, has been reported to be involved in ovary development in mammals and teleosts. However, the regulatory mechanisms of figla in ...The factor in the germline alpha(figla), as a member of the basic helix-loop-helix family, has been reported to be involved in ovary development in mammals and teleosts. However, the regulatory mechanisms of figla in teleosts remain unclear. Here,figla in P. olivaceus(Pofigla) was characterized with encoding a 202 amino acid protein that contains a conserved basic region and helix-loop-helix(HLH) domain. Amino acids alignment and synteny analysis revealed that Pofigla was conserved with the orthologous gene sequences in other vertebrates. The results of qRT-PCR showed Pofigla was maternally inherited during embryonic development. For tissue distribution, Pofigla showed a sexually dimorphic gene expression in the gonad of different genders, with a higher expression in ovary than in testis. In situ hybridization(ISH) results demonstrated Pofigla was specifically expressed in germ cells including oocytes, spermatogonia and spermatocytes. By screening and analyzing two proximal regions(-2966/-2126 and-772/-444) with high promoter activity, we found SOX5, LEF1, FOXP1 and GATA1 may play important roles in the transcriptional regulation of Pofigla. Furthermore, we observed the co-localization between Figla and LEF1 in HEK 293T cells. And the significant up-regulation effect of the canonical Wnt signaling pathway on the expression of Pofigla was found in cultured ovarian cells. This study provided the first evidence that figla not only has an important function in ovary development, but also plays some potential roles in testis development and/or male germ cell differentiation during early testis development in P. olivaceus. The results provide valuable reference in exploring the regulatory network of figla in teleost.展开更多
FOXL 2 and CYP 19 B are crucial transcription factors in vertebrates and invertebrates that play pivotal roles in sex differentiation and gonadal development.The potential roles of the foxl 2 and cyp 19 b genes in sex...FOXL 2 and CYP 19 B are crucial transcription factors in vertebrates and invertebrates that play pivotal roles in sex differentiation and gonadal development.The potential roles of the foxl 2 and cyp 19 b genes in sex determination and gonadal development in Cyprinus carpio var.koi were explored using a non-invasive RNA interference(RNAi)method,histopathological observation and qPCR.Results demonstrate that foxl 2 exhibited a sexually dimorphic expression pattern in gonads,with a notable expression in ovaries;cyp 19 b was expressed in all peripheral tissues,with a particularly prominent expression in brain and gonads.The knockdown of foxl 2 by RNAi resulted in delay in the development of the female gonads.Conversely,no notable alterations were discerned in the gonads of C.carpio var.koi following the knockdown of cyp 19 b.The upregulation of sox 9 a,amh,and cyp 19 b following foxl 2 knockdown indicates that foxl 2 may play a pivotal role in gonadal development.Nevertheless,further investigation is required to ascertain the potential role of cyp 19 b.This study elucidated the role of foxl 2 and enhanced the understanding of the mechanisms of sex determination and gonadal development in C.carpio var.koi.展开更多
Artificial lighting regimes have been successfully used to inhibit sexual maturity of Atlantic salmon in confinement.However,when these operations are applied in commercial recirculating aquaculture systems(RAS) using...Artificial lighting regimes have been successfully used to inhibit sexual maturity of Atlantic salmon in confinement.However,when these operations are applied in commercial recirculating aquaculture systems(RAS) using standard lighting technology,sexual maturation is not suppressed.In this study,an L_9(3~3) orthogonal design was used to determine the effects of three factors(spectral composition,photoperiod,and light intensity) on the gonadal development of Atlantic salmon in RAS.We demonstrated that the photoperiod at the tested levels had a much greater effect on the gonadosomatic index and female Fulton condition factor than spectral composition and light intensity.The photoperiod had a significant effect on the secretion of sex steroids and melatonin(P<0.05),and a short photoperiod delayed sex steroid and melatonin level increases.The three test factors had no significant effects on the survival rate,specific growth rate,relative weight gain,and male Fulton condition factor(P>0.05).The optimum lighting levels in female and male Atlantic salmon were LD 8:16,455 nm(or 625 nm),8.60 W/m^2;and LD 8:16,8.60 W/m^2,455 nm respectively.These conditions not only delayed gonadal development,but also had no negative effects on Atlantic salmon growth in RAS.These results demonstrate that a combination of spectral composition,photoperiod and light intensity is effective at delaying the gonadal development of both male and female salmon in RAS.展开更多
The study was made by observing the annual change of the gonadal development of amphioxus in Xiamen cohtinuously for two years from November, 1986 to November, 1988. We determined the gonadal diameter, gonadosomatic i...The study was made by observing the annual change of the gonadal development of amphioxus in Xiamen cohtinuously for two years from November, 1986 to November, 1988. We determined the gonadal diameter, gonadosomatic index of each amphioxus, and observed the histological characteristic of the gonadal development of the female and male by cut section, which provided the basis for dividing the stages gonads and the determining level of the gonadal development of amphioxus in each month.展开更多
The brain plays a critical role in controlling reproduction through the hypothalamus-pituitary-gonadal(HPG)axis in vertebrates.Turbot(Scophthalmus maximus)has become an economically important marine fish in Europe and...The brain plays a critical role in controlling reproduction through the hypothalamus-pituitary-gonadal(HPG)axis in vertebrates.Turbot(Scophthalmus maximus)has become an economically important marine fish in Europe and North China.Previous research investigating turbot reproduction has focused on the role of the HPG axis in regulating egg and sperm production.However,the morphology and histology of the organs in the HPG axis have not been studied.In this study,we investigated the morphology and histology of brains in female and male turbot at different stages of gonadal development.The results showed that the brains of both female and male turbot were composed of seven parts that are typical of advanced teleosts:the telencephalon,diencephalon,cerebellum,hypothalamus,pituitary gland,myelencephalon,and olfactory bulbs.The telencephalon was well-developed and contained five distinct lobes,with the contiguous diencephalon at the caudal portion.The torus longitudinales and rostral torus semicircularis of the mesencephalon flattened along the dorsal surface,and the rostral corpus cerebellum was located in the dorsal portion.The actual total brain volume in mature males was significantly greater(p<0.05)than that of females with gonadal development.Notably,the pituitary volume in male turbot significantly increased(p<0.05)from immature to mature stage,but this difference did not occur in females.The data together illustrate a distinct sex difference in the turbot brain during gonadal development,providing insight into their HPG axes.展开更多
The P-element induced wimpy testis(Piwi)proteins,which are associated with PIWI-interacting RNAs(piRNAs),play important roles in meiosis,germ cell division,and germline maintenance.In this study,we identified and char...The P-element induced wimpy testis(Piwi)proteins,which are associated with PIWI-interacting RNAs(piRNAs),play important roles in meiosis,germ cell division,and germline maintenance.In this study,we identified and characterized the Paralichthys olivaceus piwil2 gene,a constituent factor of the piRNA pathways involved in the biogenesis of reproductive development.The biological analysis indicated that piwil2,which contains PAZ and PIWI domains,was highly conserved between teleosts and tetrapods.The piwil2 distribution profile in different tissues confirmed a sexually dimorphic expression pattern,with a higher expression level in testis.In situ hybridization demonstrated that piwil2 was expressed in the oogonia and oocytes of the ovaries as well as in the Sertoli cells and spermatocytes of the testes.Gene piwil2 showed a maternally inherited expression pattern during embryonic development,and was highly expressed during the early embryonic development.Different luciferase reporters were constructed to determine the transcriptional regulatory mechanisms of piwil2.The piwil2 core promoter region was located at−360 bp to−60 bp.Furthermore,some representative sex hormones,including human chorionic gonadotropin,17α-methyltestosterone,and estradiol-17βhad distinct regulatory effects on piwil2.In a summery,these results indicate that piwil2,regulated by sex hormones and transcriptional elements,has vital functions in the reproductive cycle and gonadal development.展开更多
Dmrt(double-sex and mab-3 related transcription factor)基因家族编码的蛋白质是一类转录因子,具有保守的DM(double-sex/mab-3)结构域。在鱼类生长发育和进化中,Dmrt在多种生理过程尤其是性别决定和性腺发育方面起到至关重要的作用...Dmrt(double-sex and mab-3 related transcription factor)基因家族编码的蛋白质是一类转录因子,具有保守的DM(double-sex/mab-3)结构域。在鱼类生长发育和进化中,Dmrt在多种生理过程尤其是性别决定和性腺发育方面起到至关重要的作用。弓背青鳉(Oryzias curvinotus)和日本青鳉(O.latipes)均具有XX/XY性别决定系统和雄性决定基因dmrt1-bY/dmy(DM domain gene on Y chromosome),但是Dmrt基因家族在弓背青鳉中的作用尚不清楚。本研究利用生物信息学方法对弓背青鳉Dmrt基因家族的系统进化关系、基因结构、保守基序、保守结构域以及在不同组织中基因的表达水平进行分析,用实时定量PCR(real-time quantitative PCR,RT-qPCR)方法验证转录组信息。结果显示,弓背青鳉湛江群体中鉴定出Ocu_ZJ_dmrt1、Ocu_ZJ_dmy、Ocu_ZJ_dmrt2a、Ocu_ZJ_dmrt2b.1、Ocu_ZJ_dmrt2b.2、Ocu_ZJ_dmrt3、Ocu_ZJ_dmrtA1和Ocu_ZJ_dmrtA2,弓背青鳉三亚群体中鉴定出Ocu_SY_dmrt1、Ocu_SY_dmrt2a、Ocu_SY_dmrt2b、Ocu_SY_dmrt3、Ocu_SY_dmrtA1和Ocu_SY_dmrtA2。保守结构域分析显示,14个Dmrt蛋白质序列均具有DM保守结构域。利用弓背青鳉湛江群体胚胎发育转录组以及湛江和三亚群体雌雄性腺转录组数据对Dmrt基因家族进行表达水平分析,结果显示,Dmrt基因家族在胚胎各个发育时期表达不一,在两个群体的性腺中均有表达,其中Ocu_ZJ_dmy、Ocu_ZJ_dmrt1和Ocu_SY_dmrt1在雄性高表达,Ocu_ZJ_dmrt2a和Ocu_SY_dmrt2a在雌性性腺表达更高,三亚群体未检测到dmy的表达。通过RT-qPCR验证了11个差异表达基因(differentially expressed genes,DEGs)的RNA-seq数据的可靠性。本研究为青鳉属物种Dmrt基因家族的研究提供必要的基础数据,为更好地认识Dmrt基因家族在弓背青鳉性别决定和性腺、胚胎发育中的作用提供参考。展开更多
The sea urchin Heliocidaris crassispina has northern expanded in geographic range to Toga Bay,Oga Peninsula in the Sea of Japan due to the global warming.To demonstrate the gonad traits and age structure of H.crassisp...The sea urchin Heliocidaris crassispina has northern expanded in geographic range to Toga Bay,Oga Peninsula in the Sea of Japan due to the global warming.To demonstrate the gonad traits and age structure of H.crassispina in the central range and compare the difference with those in northern extended range,we collected 100 H.crassispina individuals from a barren off Shitsumi,Fukui(central range),in August 2018.Their growth,gonad traits(size,development and color),and sex ratio were investigated and compared with those in Toga Bay,in August 2014(extended range).The successive 2012–2016 year classes of H.crassispina indicated successive juvenile recruitment in the central range,as found in the extended range.The individuals at three years old in central range were obviously larger than those in the extended range,showing large test diameter and body weight,possibly due to the higher temperature in central range than that in northern extended range.In addition,a balanced sex ratio in the central range was found,in contrast to the female-skewed sex ratio found in the extended range.Gonadal development was sex-and site-dependent.The testicular development in the central range was not only delayed in comparison to ovarian development,but also less delayed than those in the extended range,which possibly attribute to the higher water temperature in the central range.A significantly lower male gonad index and L*(lightness)value was recorded in central ranges compared to that in extended range,possibly due to the releasement of sperm of H.crassispina in central ranges.展开更多
Suppressive regulatory T cells(Treg cells)play a vital role in preventing autoimmunity and restraining excessive immune response to both self-and non-self-antigens.Studies on humans and mice show that the Forkhead box...Suppressive regulatory T cells(Treg cells)play a vital role in preventing autoimmunity and restraining excessive immune response to both self-and non-self-antigens.Studies on humans and mice show that the Forkhead box p3(Foxp3)is a key regulatory gene for the development and function of Treg cells.In zebrafish,Treg cells have been identified by using foxp3a as a reliable marker.However,little is known about the function of foxp3a and Treg cells in gonadal development and sex differentiation.Here,we show that foxp3a is essential for maintaining immune homeostasis in zebrafish testis development.We found that foxp3a was specifically expressed in a subset of T cells in zebrafish testis,while knockout of foxp3a led to deficiency of foxp3a-positive Treg cells in the testis.More than 80%of foxp3a^(-/-)mutants developed as subfertile males,and the rest of the mutants developed as fertile females with decreased ovulation.Further study revealed that foxp3a^(-/-)mutants had a delayed juvenile ovary-to-testis transition in definite males and sex reversal in about half of the definite females,which led to a dominance of later male development.Owing to the absence of foxp3a-positive Treg cells in the differentiating testis of foxp3a^(-/-)mutants,abundant T cells and macrophages expand to disrupt an immunosuppressive milieu,resulting in defective development of germ cells and gonadal somatic cells and leading to development of infertile males.Therefore,our study reveals that foxp3a-positive Treg cells play an essential role in the orchestration of gonadal development and sex differentiation in zebrafish.展开更多
Eyestalk ablation has been widely used in artificial breeding of crustaceans due to its significant promotion effect on gonadal development, which plays a certain role by directly affecting neuroendocrine function of ...Eyestalk ablation has been widely used in artificial breeding of crustaceans due to its significant promotion effect on gonadal development, which plays a certain role by directly affecting neuroendocrine function of X-organ sinus gland （XO-SG） complex in eyestalks. As an important endocrine organ, XO-SG complex of the eyestalk has become a hot issue in crustacean endocrinology. This paper introduced the biological structure and physiological functions of XO-SG complex and summarized the molecular mechanism of eyestalk neuroendocrine, which provided theoretical references for further revealing the regulatory mechanism of eyestalk neuroendocrine system.展开更多
The precise assessment of the gonad status and gamete development level is an essential step in abalone breeding.However,traditional methods are damaging to the animals,causing the waste of a quality parent.Ultrasound...The precise assessment of the gonad status and gamete development level is an essential step in abalone breeding.However,traditional methods are damaging to the animals,causing the waste of a quality parent.Ultrasound imaging as a noninvasive technique is a candidate substitute.This study aimed to verify the application of ultrasonography to the assessment of abalone gonad condition.Pacific abalones(n=20)were randomly selected for ultrasonography,another six abalones in different gonad maturation stages(mature,between mature and immature,and immature)were also subjected to the same detection and histological analysis.Abalones(n=10)were induced to spawn,and the changes in the gonad index and the types of germ cells were determined before and after spawning.Thirty-six female abalones were selected and divided into a high-gonad index group(HGI)and a low-gonad index group(LGI)according to the gonad index determined by ultrasonography,and their reproductive performance was compared during the entire breeding process.There was no significant difference in gonad index or gonad relative average thickness(GRAT)obtained from ultrasonography and histological methods.The gonad index and GRAT measured by ultrasound images significantly decreased after spawning.After spawning,a minimal quantity of mature gametes remained in gonad tissue as reflected in histology images.In a reproductive trial,the HGI group showed comprehensive and overwhelming reproductive advantages compared to the LGI group in total fecundity,relative fecundity,fertilization rate,hatching rate,abnormality rate,and attachment rate.Ultrasonography was demonstrated to be useful as a noninvasive method to evaluate abalone gonad condition.The ultimate goal is to achieve tracing and monitoring the abalone reproductive cycle through the ultrasound technique.展开更多
17β-Estradiol(E2)has been widely detected in natural water and treatment with E2 induces potential endocrine disrupting effects in fish.However,effects on fish fecundity and steroid system after treatment with enviro...17β-Estradiol(E2)has been widely detected in natural water and treatment with E2 induces potential endocrine disrupting effects in fish.However,effects on fish fecundity and steroid system after treatment with environmentally relevant concentrations of E2 for the full sexual maturation cycle remain unclear.In this study,zebrafish were treatment with 0,10 or100 ng/L E2 from embryo to adult stage,and effects on gonadal development and differentiation,steroid hormone levels,transcription of genes associated with the hypothalamic-pituitary-gonadal-liver(HPG)axis in adults and fertilization rate of offspring were assessed.The results showed that treatment with E2 lead to increased number of feminization in zebrafish.In females,E2 decreased cumulative amount of spawning and inhibited the maturation of oocyte.In males,E2 inhibited the maturation and motility of sperm,as well as decreased the movement speed of sperm.These adverse effects on sperm might be responsible for the reduced fertilization observed in offspring.In addition,treatment with E2 changed the levels of steroid hormones in zebrafish gonad and altered the transcriptional levels of genes associated with HPG axis,which is responsible for the regulation of germ cells maturation and gonadal development in zebrafish.Overall,these results suggested that treatment with environmentally relevant concentrations of E2 for the full sexual maturity cycle resulted in adverse effects on reproduction in zebrafish.展开更多
lnterspecific hybridization can generate heterosis, which is proven to be a useful tool in selective breeding programs for oyster culture. Crassostrea angulata and C. ariakensis are two important economic shellfish sp...lnterspecific hybridization can generate heterosis, which is proven to be a useful tool in selective breeding programs for oyster culture. Crassostrea angulata and C. ariakensis are two important economic shellfish species in China. We conducted 2 × 2 reciprocal crosses to determine whether these two species can cross-fertilize and their hybrids can hatch, survive and perform hetero- sis. Fertilization was found symmetrical without delay. The rate of fertilization success of C. angulata ♀× C. ariakensis ♂ was lower than that of C. ariakensis ♀ x C. angulata ♂, and the success rate of both hybridizations was lower than that of two intraspecific crosses each. During the planktonic period, survival rate of the progeny was lower in the hybrid crosses than in the intraspecific crosses. On day 360, mean shell height of the progeny of C. angulata ♀ x C. angulata ♂ was highest, which was followed by that of C. angulata ♀ × C. ariakensis ♂, C. ariakensis ♀x C. ariakensis ♂ and C. ariakensis ♀× C. angulata ♂ in a descending order. Mor- phology of adults produced by the hybrid crosses was similar to that of C. angulata. Both hybrids underwent normal gonad devel- opment and produced mature gametes in the mating season. This study provided new insights into the quantitative traits in interspeci- fic crosses of Crassostrea species, thus being of guidance value for selective breeding of oyster.展开更多
The limited knowledge about the relationships between environmental factors and the maturation and reproductive seasonality of nemerteans is mostly obtained from field studies, and in many cases is conjectural. Few sp...The limited knowledge about the relationships between environmental factors and the maturation and reproductive seasonality of nemerteans is mostly obtained from field studies, and in many cases is conjectural. Few species have been studied under well-controlled laboratory conditions. In this work, the effects of temperature and photoperiod on gonad development and spawning of Cephalothrix hongkongiensis were observed by rearing worms under different temperatures and photoperiods. Worms reared at 4~C and 6~C showed no growth or gonadal development, and all died within 109 days. At 8~C and 12~C, gonads could be seen from 90 days to the termination of the 360-day experiment, but no spawning was observed. Worms maintained at 16, 24, and 28~C showed both gonadal development and spawning, and matured faster at higher temperatures. Under a fixed temperature （16℃）, photoperiod did not have any significant impact on maturation and spawning. It is likely that temperature plays a major role in regulating the maturation and reproductive cycle of C. hongkongiensis.展开更多
文摘A twelve week experiment was conducted to compare the effects of diets with plant-based and animal-based ingredients on growth and gonad development of Clarias gariepinus. One hundred and 12 sub-adult C. gariepinus with an average weight of 205 ×5.09 g, were stocked in six concrete tanks （9 × 4 × 2 m3） containing 20 fish each. Experiment had 3 replicates and animals fed daily at 5% body weights. There was no significant difference （P 〈 0.05） in proximate compositions of the two experimental feeds and controls. Fecundity, gonad weight and gonasomatic index were higher in fish fed diet 13 than A and C. Similarly, growth indices were higher in fish fed diet B than in A and C. Histology of gonads showed a faster development of oocytes of eggs in fish fed animal-based ingredients than plant-based and combined plant and animal diets. Although there were slight differences in growth parameters and gonad development in favor of feed with animal-based ingredients, plant-based feed compared favorably in the growth and gonad development of C. gariepinus. Plant-based ingredients are recommended on the basis of affordability and availability as substitute for animal-based ingredients in C. gariepinus feed.
基金supported by the National Key R&D Program of China (No. 2018YFD0901205)
文摘The factor in the germline alpha(figla), as a member of the basic helix-loop-helix family, has been reported to be involved in ovary development in mammals and teleosts. However, the regulatory mechanisms of figla in teleosts remain unclear. Here,figla in P. olivaceus(Pofigla) was characterized with encoding a 202 amino acid protein that contains a conserved basic region and helix-loop-helix(HLH) domain. Amino acids alignment and synteny analysis revealed that Pofigla was conserved with the orthologous gene sequences in other vertebrates. The results of qRT-PCR showed Pofigla was maternally inherited during embryonic development. For tissue distribution, Pofigla showed a sexually dimorphic gene expression in the gonad of different genders, with a higher expression in ovary than in testis. In situ hybridization(ISH) results demonstrated Pofigla was specifically expressed in germ cells including oocytes, spermatogonia and spermatocytes. By screening and analyzing two proximal regions(-2966/-2126 and-772/-444) with high promoter activity, we found SOX5, LEF1, FOXP1 and GATA1 may play important roles in the transcriptional regulation of Pofigla. Furthermore, we observed the co-localization between Figla and LEF1 in HEK 293T cells. And the significant up-regulation effect of the canonical Wnt signaling pathway on the expression of Pofigla was found in cultured ovarian cells. This study provided the first evidence that figla not only has an important function in ovary development, but also plays some potential roles in testis development and/or male germ cell differentiation during early testis development in P. olivaceus. The results provide valuable reference in exploring the regulatory network of figla in teleost.
基金Supported by the Qingdao Aquarium Technology Collaborative Innovation Center Cooperation Project(No.20210021)the Researching Key Technologies for Selecting Excellent Koi Carp Germplasm(No.20223702032291)the Qingdao Agricultural University Tangwang Koi Carp Joint R&D Center Collaborative Project(No.20220271)。
文摘FOXL 2 and CYP 19 B are crucial transcription factors in vertebrates and invertebrates that play pivotal roles in sex differentiation and gonadal development.The potential roles of the foxl 2 and cyp 19 b genes in sex determination and gonadal development in Cyprinus carpio var.koi were explored using a non-invasive RNA interference(RNAi)method,histopathological observation and qPCR.Results demonstrate that foxl 2 exhibited a sexually dimorphic expression pattern in gonads,with a notable expression in ovaries;cyp 19 b was expressed in all peripheral tissues,with a particularly prominent expression in brain and gonads.The knockdown of foxl 2 by RNAi resulted in delay in the development of the female gonads.Conversely,no notable alterations were discerned in the gonads of C.carpio var.koi following the knockdown of cyp 19 b.The upregulation of sox 9 a,amh,and cyp 19 b following foxl 2 knockdown indicates that foxl 2 may play a pivotal role in gonadal development.Nevertheless,further investigation is required to ascertain the potential role of cyp 19 b.This study elucidated the role of foxl 2 and enhanced the understanding of the mechanisms of sex determination and gonadal development in C.carpio var.koi.
基金Supported by the National Key Technologies R&D Program of China(No.2011BAD13B04)the Knowledge Innovation Program of Chinese Academy of Sciences(No.KZCX2-EW-Q212)+2 种基金the Public Service Sectors(Agriculture)Special Project(No.201003024)the Earmarked Fund for Modern Agro-Industry Technology Research Systemthe Shandong Program for Development of Science and Technology(No.2013GHY11514)
文摘Artificial lighting regimes have been successfully used to inhibit sexual maturity of Atlantic salmon in confinement.However,when these operations are applied in commercial recirculating aquaculture systems(RAS) using standard lighting technology,sexual maturation is not suppressed.In this study,an L_9(3~3) orthogonal design was used to determine the effects of three factors(spectral composition,photoperiod,and light intensity) on the gonadal development of Atlantic salmon in RAS.We demonstrated that the photoperiod at the tested levels had a much greater effect on the gonadosomatic index and female Fulton condition factor than spectral composition and light intensity.The photoperiod had a significant effect on the secretion of sex steroids and melatonin(P<0.05),and a short photoperiod delayed sex steroid and melatonin level increases.The three test factors had no significant effects on the survival rate,specific growth rate,relative weight gain,and male Fulton condition factor(P>0.05).The optimum lighting levels in female and male Atlantic salmon were LD 8:16,455 nm(or 625 nm),8.60 W/m^2;and LD 8:16,8.60 W/m^2,455 nm respectively.These conditions not only delayed gonadal development,but also had no negative effects on Atlantic salmon growth in RAS.These results demonstrate that a combination of spectral composition,photoperiod and light intensity is effective at delaying the gonadal development of both male and female salmon in RAS.
文摘The study was made by observing the annual change of the gonadal development of amphioxus in Xiamen cohtinuously for two years from November, 1986 to November, 1988. We determined the gonadal diameter, gonadosomatic index of each amphioxus, and observed the histological characteristic of the gonadal development of the female and male by cut section, which provided the basis for dividing the stages gonads and the determining level of the gonadal development of amphioxus in each month.
基金The National Natural Science Foundation of China under contract Nos 31802319,31972784,31802269the Natural Science Foundation of Shandong Province under contract No.ZR2018BC053+1 种基金the Agricultural Application Technology Innovation Project of Shandong Province under contract No.SD2019YY006the Advanced Talents Foundation of Qingdao Agricultural University under contract Nos 6631119055,6631119032.
文摘The brain plays a critical role in controlling reproduction through the hypothalamus-pituitary-gonadal(HPG)axis in vertebrates.Turbot(Scophthalmus maximus)has become an economically important marine fish in Europe and North China.Previous research investigating turbot reproduction has focused on the role of the HPG axis in regulating egg and sperm production.However,the morphology and histology of the organs in the HPG axis have not been studied.In this study,we investigated the morphology and histology of brains in female and male turbot at different stages of gonadal development.The results showed that the brains of both female and male turbot were composed of seven parts that are typical of advanced teleosts:the telencephalon,diencephalon,cerebellum,hypothalamus,pituitary gland,myelencephalon,and olfactory bulbs.The telencephalon was well-developed and contained five distinct lobes,with the contiguous diencephalon at the caudal portion.The torus longitudinales and rostral torus semicircularis of the mesencephalon flattened along the dorsal surface,and the rostral corpus cerebellum was located in the dorsal portion.The actual total brain volume in mature males was significantly greater(p<0.05)than that of females with gonadal development.Notably,the pituitary volume in male turbot significantly increased(p<0.05)from immature to mature stage,but this difference did not occur in females.The data together illustrate a distinct sex difference in the turbot brain during gonadal development,providing insight into their HPG axes.
基金This study was supported by the National Natural Science Foundation of China(No.31672646)the Natural Science Foundation of Shandong Province(No.ZR 2017MC072).
文摘The P-element induced wimpy testis(Piwi)proteins,which are associated with PIWI-interacting RNAs(piRNAs),play important roles in meiosis,germ cell division,and germline maintenance.In this study,we identified and characterized the Paralichthys olivaceus piwil2 gene,a constituent factor of the piRNA pathways involved in the biogenesis of reproductive development.The biological analysis indicated that piwil2,which contains PAZ and PIWI domains,was highly conserved between teleosts and tetrapods.The piwil2 distribution profile in different tissues confirmed a sexually dimorphic expression pattern,with a higher expression level in testis.In situ hybridization demonstrated that piwil2 was expressed in the oogonia and oocytes of the ovaries as well as in the Sertoli cells and spermatocytes of the testes.Gene piwil2 showed a maternally inherited expression pattern during embryonic development,and was highly expressed during the early embryonic development.Different luciferase reporters were constructed to determine the transcriptional regulatory mechanisms of piwil2.The piwil2 core promoter region was located at−360 bp to−60 bp.Furthermore,some representative sex hormones,including human chorionic gonadotropin,17α-methyltestosterone,and estradiol-17βhad distinct regulatory effects on piwil2.In a summery,these results indicate that piwil2,regulated by sex hormones and transcriptional elements,has vital functions in the reproductive cycle and gonadal development.
文摘Dmrt(double-sex and mab-3 related transcription factor)基因家族编码的蛋白质是一类转录因子,具有保守的DM(double-sex/mab-3)结构域。在鱼类生长发育和进化中,Dmrt在多种生理过程尤其是性别决定和性腺发育方面起到至关重要的作用。弓背青鳉(Oryzias curvinotus)和日本青鳉(O.latipes)均具有XX/XY性别决定系统和雄性决定基因dmrt1-bY/dmy(DM domain gene on Y chromosome),但是Dmrt基因家族在弓背青鳉中的作用尚不清楚。本研究利用生物信息学方法对弓背青鳉Dmrt基因家族的系统进化关系、基因结构、保守基序、保守结构域以及在不同组织中基因的表达水平进行分析,用实时定量PCR(real-time quantitative PCR,RT-qPCR)方法验证转录组信息。结果显示,弓背青鳉湛江群体中鉴定出Ocu_ZJ_dmrt1、Ocu_ZJ_dmy、Ocu_ZJ_dmrt2a、Ocu_ZJ_dmrt2b.1、Ocu_ZJ_dmrt2b.2、Ocu_ZJ_dmrt3、Ocu_ZJ_dmrtA1和Ocu_ZJ_dmrtA2,弓背青鳉三亚群体中鉴定出Ocu_SY_dmrt1、Ocu_SY_dmrt2a、Ocu_SY_dmrt2b、Ocu_SY_dmrt3、Ocu_SY_dmrtA1和Ocu_SY_dmrtA2。保守结构域分析显示,14个Dmrt蛋白质序列均具有DM保守结构域。利用弓背青鳉湛江群体胚胎发育转录组以及湛江和三亚群体雌雄性腺转录组数据对Dmrt基因家族进行表达水平分析,结果显示,Dmrt基因家族在胚胎各个发育时期表达不一,在两个群体的性腺中均有表达,其中Ocu_ZJ_dmy、Ocu_ZJ_dmrt1和Ocu_SY_dmrt1在雄性高表达,Ocu_ZJ_dmrt2a和Ocu_SY_dmrt2a在雌性性腺表达更高,三亚群体未检测到dmy的表达。通过RT-qPCR验证了11个差异表达基因(differentially expressed genes,DEGs)的RNA-seq数据的可靠性。本研究为青鳉属物种Dmrt基因家族的研究提供必要的基础数据,为更好地认识Dmrt基因家族在弓背青鳉性别决定和性腺、胚胎发育中的作用提供参考。
基金Supported by the Zhejiang Provincial Department of Science and Technology,“Pioneer”and“Leading Goose”R&D Program of Zhejiang (No.2022C02040)the Science and Technology Bureau of Zhoushan (No.2022C41021)。
文摘The sea urchin Heliocidaris crassispina has northern expanded in geographic range to Toga Bay,Oga Peninsula in the Sea of Japan due to the global warming.To demonstrate the gonad traits and age structure of H.crassispina in the central range and compare the difference with those in northern extended range,we collected 100 H.crassispina individuals from a barren off Shitsumi,Fukui(central range),in August 2018.Their growth,gonad traits(size,development and color),and sex ratio were investigated and compared with those in Toga Bay,in August 2014(extended range).The successive 2012–2016 year classes of H.crassispina indicated successive juvenile recruitment in the central range,as found in the extended range.The individuals at three years old in central range were obviously larger than those in the extended range,showing large test diameter and body weight,possibly due to the higher temperature in central range than that in northern extended range.In addition,a balanced sex ratio in the central range was found,in contrast to the female-skewed sex ratio found in the extended range.Gonadal development was sex-and site-dependent.The testicular development in the central range was not only delayed in comparison to ovarian development,but also less delayed than those in the extended range,which possibly attribute to the higher water temperature in the central range.A significantly lower male gonad index and L*(lightness)value was recorded in central ranges compared to that in extended range,possibly due to the releasement of sperm of H.crassispina in central ranges.
基金supported by the National Key Research and Development Program of China(2018YFD0900505 to Y.-A.Z.and 2018YFA0801000 to Y.S.)the National Natural Science Foundation of China(32025037 and 31721005 to Y.S.)。
文摘Suppressive regulatory T cells(Treg cells)play a vital role in preventing autoimmunity and restraining excessive immune response to both self-and non-self-antigens.Studies on humans and mice show that the Forkhead box p3(Foxp3)is a key regulatory gene for the development and function of Treg cells.In zebrafish,Treg cells have been identified by using foxp3a as a reliable marker.However,little is known about the function of foxp3a and Treg cells in gonadal development and sex differentiation.Here,we show that foxp3a is essential for maintaining immune homeostasis in zebrafish testis development.We found that foxp3a was specifically expressed in a subset of T cells in zebrafish testis,while knockout of foxp3a led to deficiency of foxp3a-positive Treg cells in the testis.More than 80%of foxp3a^(-/-)mutants developed as subfertile males,and the rest of the mutants developed as fertile females with decreased ovulation.Further study revealed that foxp3a^(-/-)mutants had a delayed juvenile ovary-to-testis transition in definite males and sex reversal in about half of the definite females,which led to a dominance of later male development.Owing to the absence of foxp3a-positive Treg cells in the differentiating testis of foxp3a^(-/-)mutants,abundant T cells and macrophages expand to disrupt an immunosuppressive milieu,resulting in defective development of germ cells and gonadal somatic cells and leading to development of infertile males.Therefore,our study reveals that foxp3a-positive Treg cells play an essential role in the orchestration of gonadal development and sex differentiation in zebrafish.
基金Supported by Special Fund for Agro-scientific Research in the Public Interest(201003070)Youth Fund from Natural Science Foundation of Jiangsu Province(BK2012090)Central Public-interest Scientific Institution Basal Research Fund(2013JBFM09)
文摘Eyestalk ablation has been widely used in artificial breeding of crustaceans due to its significant promotion effect on gonadal development, which plays a certain role by directly affecting neuroendocrine function of X-organ sinus gland （XO-SG） complex in eyestalks. As an important endocrine organ, XO-SG complex of the eyestalk has become a hot issue in crustacean endocrinology. This paper introduced the biological structure and physiological functions of XO-SG complex and summarized the molecular mechanism of eyestalk neuroendocrine, which provided theoretical references for further revealing the regulatory mechanism of eyestalk neuroendocrine system.
基金supported by grants from National Natural Science Foundation of China(No.U22A20530)the Key S&T Program of Fujian Province(No.2020NZ08003)+1 种基金Seed Industry Innovation and Industrialization in Fujian Province(No.2021FJSCZY02)the Earmarked Fund for CARS(No.CARS-49).
文摘The precise assessment of the gonad status and gamete development level is an essential step in abalone breeding.However,traditional methods are damaging to the animals,causing the waste of a quality parent.Ultrasound imaging as a noninvasive technique is a candidate substitute.This study aimed to verify the application of ultrasonography to the assessment of abalone gonad condition.Pacific abalones(n=20)were randomly selected for ultrasonography,another six abalones in different gonad maturation stages(mature,between mature and immature,and immature)were also subjected to the same detection and histological analysis.Abalones(n=10)were induced to spawn,and the changes in the gonad index and the types of germ cells were determined before and after spawning.Thirty-six female abalones were selected and divided into a high-gonad index group(HGI)and a low-gonad index group(LGI)according to the gonad index determined by ultrasonography,and their reproductive performance was compared during the entire breeding process.There was no significant difference in gonad index or gonad relative average thickness(GRAT)obtained from ultrasonography and histological methods.The gonad index and GRAT measured by ultrasound images significantly decreased after spawning.After spawning,a minimal quantity of mature gametes remained in gonad tissue as reflected in histology images.In a reproductive trial,the HGI group showed comprehensive and overwhelming reproductive advantages compared to the LGI group in total fecundity,relative fecundity,fertilization rate,hatching rate,abnormality rate,and attachment rate.Ultrasonography was demonstrated to be useful as a noninvasive method to evaluate abalone gonad condition.The ultimate goal is to achieve tracing and monitoring the abalone reproductive cycle through the ultrasound technique.
基金supported by the National Key R&D Program of China (No.2019YFD1100501)。
文摘17β-Estradiol(E2)has been widely detected in natural water and treatment with E2 induces potential endocrine disrupting effects in fish.However,effects on fish fecundity and steroid system after treatment with environmentally relevant concentrations of E2 for the full sexual maturation cycle remain unclear.In this study,zebrafish were treatment with 0,10 or100 ng/L E2 from embryo to adult stage,and effects on gonadal development and differentiation,steroid hormone levels,transcription of genes associated with the hypothalamic-pituitary-gonadal-liver(HPG)axis in adults and fertilization rate of offspring were assessed.The results showed that treatment with E2 lead to increased number of feminization in zebrafish.In females,E2 decreased cumulative amount of spawning and inhibited the maturation of oocyte.In males,E2 inhibited the maturation and motility of sperm,as well as decreased the movement speed of sperm.These adverse effects on sperm might be responsible for the reduced fertilization observed in offspring.In addition,treatment with E2 changed the levels of steroid hormones in zebrafish gonad and altered the transcriptional levels of genes associated with HPG axis,which is responsible for the regulation of germ cells maturation and gonadal development in zebrafish.Overall,these results suggested that treatment with environmentally relevant concentrations of E2 for the full sexual maturity cycle resulted in adverse effects on reproduction in zebrafish.
基金supported by the National Natural Science Foundation of China(Grant No.31172403)the National Key Basic Research Development Planning Project(Grant No.2010CB126406)
文摘lnterspecific hybridization can generate heterosis, which is proven to be a useful tool in selective breeding programs for oyster culture. Crassostrea angulata and C. ariakensis are two important economic shellfish species in China. We conducted 2 × 2 reciprocal crosses to determine whether these two species can cross-fertilize and their hybrids can hatch, survive and perform hetero- sis. Fertilization was found symmetrical without delay. The rate of fertilization success of C. angulata ♀× C. ariakensis ♂ was lower than that of C. ariakensis ♀ x C. angulata ♂, and the success rate of both hybridizations was lower than that of two intraspecific crosses each. During the planktonic period, survival rate of the progeny was lower in the hybrid crosses than in the intraspecific crosses. On day 360, mean shell height of the progeny of C. angulata ♀ x C. angulata ♂ was highest, which was followed by that of C. angulata ♀ × C. ariakensis ♂, C. ariakensis ♀x C. ariakensis ♂ and C. ariakensis ♀× C. angulata ♂ in a descending order. Mor- phology of adults produced by the hybrid crosses was similar to that of C. angulata. Both hybrids underwent normal gonad devel- opment and produced mature gametes in the mating season. This study provided new insights into the quantitative traits in interspeci- fic crosses of Crassostrea species, thus being of guidance value for selective breeding of oyster.
基金Supported by the National Natural Science Foundation of China(Nos.30970333,31172046)
文摘The limited knowledge about the relationships between environmental factors and the maturation and reproductive seasonality of nemerteans is mostly obtained from field studies, and in many cases is conjectural. Few species have been studied under well-controlled laboratory conditions. In this work, the effects of temperature and photoperiod on gonad development and spawning of Cephalothrix hongkongiensis were observed by rearing worms under different temperatures and photoperiods. Worms reared at 4~C and 6~C showed no growth or gonadal development, and all died within 109 days. At 8~C and 12~C, gonads could be seen from 90 days to the termination of the 360-day experiment, but no spawning was observed. Worms maintained at 16, 24, and 28~C showed both gonadal development and spawning, and matured faster at higher temperatures. Under a fixed temperature （16℃）, photoperiod did not have any significant impact on maturation and spawning. It is likely that temperature plays a major role in regulating the maturation and reproductive cycle of C. hongkongiensis.
