SRY (sex-determining region Y chromosome) is considered as a strong candidste for the TDF (testis determining factor) and has been cloned following another candidate ZFY (zinc finger protein gene). In this study,eight...SRY (sex-determining region Y chromosome) is considered as a strong candidste for the TDF (testis determining factor) and has been cloned following another candidate ZFY (zinc finger protein gene). In this study,eight cases of sex revelsal, including four 46, XX males and four 46, XY females aere examined for the presence of SRY sequence and a Y-repeated DNA locus. Our data indicated that the genownic DNA of the four classical 46,XX males had the SRY sequences. On the other hand, both SRY sequences and Ye repeated DNA sequences were present in all four 46, XY females.These resultssuavest that SAY sequences were responsible for the sexraversal of 46, XX males Whereas there may be other genetic mechanisms forthe sex reversal of 46, XY females Without the lack of SRY sequences.展开更多
Fadrozole, an aromatase inhibitor, can masculinize genetic female chickens and high-dose decreases the hatchability. Therefore, it is important to study the growth and development of sex-reversed females after hatch. ...Fadrozole, an aromatase inhibitor, can masculinize genetic female chickens and high-dose decreases the hatchability. Therefore, it is important to study the growth and development of sex-reversed females after hatch. Chick embryos from a population of CAU3 egg-type were treated with different concentrations of Fadrozole prior to the sexual differentiation at E3.0 （st18）. At hatch, the phenotypic sex and genetic sex were identified by vent sexing and genetic diagnosis with CHD1, respectively. Body weight and shank length of sex reversal were tested at 8 and 20 wk, respectively. Testicular development, oviduct and ovarian degeneration were observed and serum concentration of estradiol and testosterone were tested with radioimmunoassay （RIA） at 30 wk. The results showed that body weight and shank length of sex- reversed females were not significantly different between low-dose groups （0.1, 0.3, and 0.5 mg for F1, F2, and F3, respectively） and high-dose groups （1.0 and 1.3 mg for F4 and F5, respectively） （P〉0.05）. Left and right testes or ovotestes in F2, F3, F4, and F5 groups were heavier than that of in F1 group （P〈0.05）. While the gonad weight of treatment groups were less than that in male control （P〈0.05）, oviduct weight in F2, F3, F4, and F5 groups were significant differences compared with female control and F1 group （P〈0.05）. Egg number from onset of laying egg to 30 wk in F4 and F5 groups were less than in female control, F1 and F2 groups （P〈0.05）. Serum testosterone level in F5 group was significant higher compared with female control, F1, F2, F3, and F4 groups （P〈0.05）, but significant lower compared with male control （P〈0.05）. While concentration of serum estradiol in F5 group was significant lower compared with female control, F1, F2, and F4 groups （P〈0.05）. In conclusion, the concentration of Fadrozole do not affect postnatal growth of sex-reversed female chicken and the degree of sex-reversed females elevate with the increase of Fadrozole concentration at sex maturity.展开更多
Disorders of sex development often arise from anomalies in the molecular or cellular networks that guide the differentiation of the embryonic gonad into either a testis or an ovary, two functionally distinct organs. T...Disorders of sex development often arise from anomalies in the molecular or cellular networks that guide the differentiation of the embryonic gonad into either a testis or an ovary, two functionally distinct organs. The activation of the Y-linked gene Sry （sex- determining region Y） and its downstream target Sox9 （Sry box-containing gene 9） triggers testis differentiation by stimulating the differentiation of Sertoli cells, which then direct testis morphogenesis. Once engaged, a genetic pathway promotes the testis development while actively suppressing genes involved in ovarian development. This review focuses on the events of testis determination and the struggle to maintain male fate in the face of antagonistic pressure from the underlying female programme.展开更多
The sexual differentiation of germ cells into spermatozoa or oocytes is strictly regulated by their gonadal environment, testis or ovary, which is determined by the presence or absence of the Y chromosome, respectivel...The sexual differentiation of germ cells into spermatozoa or oocytes is strictly regulated by their gonadal environment, testis or ovary, which is determined by the presence or absence of the Y chromosome, respectively. Hence, in normal mammalian development, male germ cells differentiate in the presence of X and Y chromosomes, and female germ cells do so in the presence of two X chromosomes. However, gonadal sex reversal occurs in humans as well as in other mammalian species, and the resultant XX males and XY females can lead healthy lives, except for a complete or partial loss of fertility. Germ cells carrying an abnormal set of sex chromosomes are efficiently eliminated by multilayered surveillance mechanisms in the testis, and also, though more variably, in the ovary. Studying the molecular basis for sex-specific responses to a set of sex chromosomes during gametogenesis will promote our understanding of meiotic processes contributing to the evolution of sex determining mechanisms. This review discusses the fate of germ cells carrying various sex chromosomal compositions in mouse models, the limitation of which may be overcome by recent successes in the differentiation of functional germ cells from embryonic stem cells under experimental conditions.展开更多
Sex emerges out of a delicate dance between a variety of promale, anti-male, and possibly profemale genes. To investigate the role that sex-related genes play in sex determination and gonadal differentiation of fowl, ...Sex emerges out of a delicate dance between a variety of promale, anti-male, and possibly profemale genes. To investigate the role that sex-related genes play in sex determination and gonadal differentiation of fowl, we constructed a male-to- female sex-reversal model of chick induced by diethylstilbestrol （DES） at onset of incubation （E0）. The results of semi- quantitative PCR showed that the expression of Sf1, the orphan nuclear receptor steroidogenic factor-1 gene, was put forward from E7d to E5d and up-regulated during E5-7d; the Dmrt1, the double sex and the Mab-3 related to transcription factor 1 gene, was down-regulated during E3-7d. Meanwhile, anti-Müllerian hormone gene （Amh） expressed at a similar level in the genetic females and sex-reversal females before E7d, while no expression products of the three female-specific genes Wpkci, Fet1 and Foxl2 were detected in male-to-female embryos. These findings suggest that the expression of some certain sex-related genes, induced by the exogenous estrogen during period of sex determination and gonadal differentiation, results in the male-to-female sex reversal. Moreover, high activity of Sf1 gene during E5-7d might be related to the profemale process, while low activity of Dmrt1 gene during E3-5d might be anti-male. The expression activity of Amh gene might only contribute to the promale process after E7d, however, it is possibly not an anti-female gene in chick embryos.展开更多
In sex role reversed species, predominantly females evolve sexually selected traits, such as ornaments and/or weapons. Female ornaments are common and their function well documented in many species, whether sex role r...In sex role reversed species, predominantly females evolve sexually selected traits, such as ornaments and/or weapons. Female ornaments are common and their function well documented in many species, whether sex role reversed or not. However, sexually selected female weapons seem totally absent except for small wing spurs in three jacana species, present in both males and females. This poor female weaponry is in sharp contrast to the situation in species with conventional sex roles： males com- monly have evolved sexually selected weapons as well as ornaments. At the same time, females in many taxa have naturally se- lected weapons, used in competition over resources or in predator defence. Why are sexually selected weapons then so rare, al- most absent, in females？ Here I briefly review weaponry in females and the function of these weapons, conclude that the near ab- sence of sexually selected weapons begs an explanation, and suggest that costs of sexually selected weapons may exceed costs of ornaments. Females are more constrained when evolving sexually selected traits compared to males, at least compared to those males that do not provide direct benefits, as trait costs reduce a female＇s fecundity. I suggest that this constraining trade-off between trait and fecundity restricts females to evolve ornaments but rarely weapons. The same may apply to paternally investing males. Whether sexually selected weapons actually are more costly than sexually selected ornaments remains to be investigated展开更多
Sex-determining systems show a striking diversity not only among species, but also among popula tions. In reptiles, sex-determina tion is a continuum, from tempera ture-dependent sex determination(TSD) to genetic sex ...Sex-determining systems show a striking diversity not only among species, but also among popula tions. In reptiles, sex-determina tion is a continuum, from tempera ture-dependent sex determination(TSD) to genetic sex determination(GSD).The multi-ocellated racerunner(Eremias multiocellata)is reported to be a cryptic ZZ/ZW chromosomal TSD species, with male-biased sex ratios at high temperatures in two Gansu populations. However, the generality of the sex-determining pattern in different populations of this species remains unclear. To investigate the mode of sex determina tion in a popula tion of E.multiocellata from the desert steppe of Inner Mongolia,we first identified sex chromosomes via comparative genomic hybridization(CGH). We then conducted a thermal manipulation experiment to determine the effect of gestation temperature on offspring sex ratios.From the CGH studies we found that lizards from the Inner Mongolia population possessed ZZ/ZW sex chromosomes. However, our thermal manipulation experiment showed that gestation temperature did not affect the sex ratio of neonates in this population. In combination, these results rule out TSD in the Inner Mongolia population of E. multiocellata, and suggest that there is widespread geographic variation in the sexdetermining system of this species.展开更多
In reptiles,such as the red-eared slider turtle(Trachemys scripta elegans),gonadal sex determination is highly dependent on the environmental temperature during embryonic stages.This complex process,which leads to dif...In reptiles,such as the red-eared slider turtle(Trachemys scripta elegans),gonadal sex determination is highly dependent on the environmental temperature during embryonic stages.This complex process,which leads to differentiation into either testes or ovaries,is governed by the finely tuned expression of upstream genes,notably the testis-promoting gene Dmrt1 and the ovary-promoting gene Foxl2.Recent studies have identified epigenetic regulation as a crucial factor in testis development,with the H3K27me3 demethylase KDM6B being essential for Dmrt1 expression in T.s.elegans.However,whether KDM6B alone can induce testicular differentiation remains unclear.In this study,we found that overexpression of Kdm6b in T.s.elegans embryos induced the male development pathway,accompanied by a rapid increase in the gonadal expression of Dmrt1 at 31°C,a temperature typically resulting in female development.Notably,this sex reversal could be entirely rescued by Dmrt1 knockdown.These findings demonstrate that Kdm6b is sufficient for commitment to the male pathway,underscoring its role as a critical epigenetic regulator in the sex determination of the red-eared slider turtle.展开更多
This study was conducted to determine the effective dose of 17α-methyltestosterone(MT)that produces all-male fry of black-chinned tilapia,Sarotherodon melanotheron.Five concentrations:0,30,60,90 and 120 mg 17α-methy...This study was conducted to determine the effective dose of 17α-methyltestosterone(MT)that produces all-male fry of black-chinned tilapia,Sarotherodon melanotheron.Five concentrations:0,30,60,90 and 120 mg 17α-methyltestosterone(17α-MT)per kilogram feed were prepared using the ethanol evaporation method,and administered orally to black-chinned tilapia fry for 28 days in triplicate aquarium glass tanks.After the treatment period,triplicates of 60 fry from each treatment were stocked in hapas and further cultured in freshwater ponds.They were fed with commercial fish feed ad libitum.The sex ratio,growth performance and survival were evaluated after 60 and 180 days.At the end of the 60-day period,the sex ratio of 30 fish from each treatment was determined by using the gonadal squash method.The remaining 30 fish from each treatment were grown further for 180 days and their sex ratio determined using the genital papillae.The results demonstrated that 17α-methyltestosterone was effective in producing phenotypic male in S.melanotheron.However,in both 60-day and 180-day experiments,no treatment gave 100%male population.The 90 mg/kg MT yielded the highest all-male fish of 84.13%,highest survival of 70%and highest final mean body weight of 103.99±7.92 g.展开更多
The aim of the present study was to investigate the long-term effects of 17l）-estradiol （E2） exposure on gonadal development in the tiger puffer （Taktfugu rubripes）, which has a genetic sex determination system o...The aim of the present study was to investigate the long-term effects of 17l）-estradiol （E2） exposure on gonadal development in the tiger puffer （Taktfugu rubripes）, which has a genetic sex determination system of male homogametic XY-XX. Tiger puffer larvae were exposed to 1, 10 and 100 μg/L E2 from 15 to 100 days post-hatch （dph） and then maintained in clean seawater until 400 dph. Changes in sex ratio, gonadal structure and gonadosomatic index （GSI） were monitored at 100, 160, 270 and 400 dph. Sex-associated single nucleotide polymorphism （SNP） markers were used to analyze the genetic sex of samples, except those at 100 dph. Exposure had a positive effect on the conversion of genetically male gonads into phenotypically female gonads at 100 dph. However, gonads from 60% of genetic XY males in the 1-μg/L E2 group and 100% in the 10-μg/L E2 group developed intersexual gonads at 160 dph; gonads of all genetic XY males in the two treatment groups reverted to testis by 270 dph. While 38%, 57% and 44% of gonads of XY fish in the 100-gg/L E2 group reverted to intersexual gonads at 160, 270 and 400 dph, respectively, none reverted to testis after E2 treatment. In addition, E2 exposure inhibited gonadal growth of both genetic sexes, as indicated by the clear dose-dependent decrease in GSI at 270 and 400 dph. The results showed that exposure to E2 during the early life stages of tiger puffer disrupted gonadal development, but that fish recovered after migration to clean seawater. The study suggests the potential use of tiger puffer as a valuable indicator species to evaluate the effects of environmental estrogens on marine fish, thereby protecting valuable fishery resources.展开更多
Intersexualism occurs in all species of maxnmals and the pathogenesis of abnormal development of the gonads is still unclear. Thus, the aim of this report is to describe the hormonal and histopathological findings fro...Intersexualism occurs in all species of maxnmals and the pathogenesis of abnormal development of the gonads is still unclear. Thus, the aim of this report is to describe the hormonal and histopathological findings from a case of bilateral true hermaphroditism in a mixed-breed bitch due to the few case reports published involving hormonal levels in dogs with intersexuality. Serum was obtained from the animal before surgery and was submitted to hormone measurements. Progesterone and testosterone were evaluated by radioimnunoassay and estrogen by ELISA （immune-enzymatic assay）. The values of progesterone, testosterone and estrogen concentrations were 2.26 ng/mL, 0.05 ng/mL and 9.7 pg/mL, respectively. The proportion of ovarian tissue found in the ovotestes after histopathological examination was higher in relation to seminiferous tubules, which may explain the low level of serum testosterone. Low concentration of serum testosterone may have contributed to the partial virilization of external genitalia, since the animal only had clitoral hypertrophy. Estrogen and progesterone levels found were compatible with the initial stage of estrus （preovulatory LH （luteinizing hormone） surge）, which shows that ovarian follicles found in the bilateral ovotestes contributed to the occurrence of the estrous cycle before surgery. Quantitation of serum hormones may also shed light on the cause of disturbances in sex differentiation in canine species. More studies are needed to elucidate the real cause of intersex in dogs.展开更多
The ricefield eel(Monopterus albus),a protogynous hermaphrodite,is an important aquaculture freshwater fish in China.Intensive studies have focused on the sex reversal of this species,but the underlying mechanisms rem...The ricefield eel(Monopterus albus),a protogynous hermaphrodite,is an important aquaculture freshwater fish in China.Intensive studies have focused on the sex reversal of this species,but the underlying mechanisms remain elusive.We performed comparative transcriptome analysis for gonadal tissues of female,intersex,and male ricefield eels.The results suggest that temperature may play a role in inducing the sex reversal.Moreover,an epithelial-mesenchymal transition(EMT)gene signature was found,suggesting an involvement of germinal epithelium in contributing to gonadal transformation.Our in vitro and in vivo experiments show that thermal cues are sensed by thermosensors such as Trpv4 in the gonadal cells of ricefield eels,which can be transduced to the sex determination cascades.The epithelial cells of germinal epithelium can become Sertoli cells via an EMT.Our study provides new insights into the molecular mechanisms underlying the sex reversal of ricefield eels.展开更多
We present results of a long-term study aimed to optimize Nile tilapia O. niloticus production in a recirculating aquaculture system (RAS) in México City. Three experiments were evaluated: 1) fry production;2) pr...We present results of a long-term study aimed to optimize Nile tilapia O. niloticus production in a recirculating aquaculture system (RAS) in México City. Three experiments were evaluated: 1) fry production;2) production of masculinized fries;and 3) assessment of growth under three different densities (10, 30 and 75 fish/m3). The broodstock produced on average 2400 ± 600 fry every 15 days during six months, with a total production of 28,800 ± 2000. One hundred percent males were produced in 274-L raceways in an eight-week period. The obtained results in fish production in the RAS system indicated variations related to density. A daily growth rate of 3.6 g/day was registered with a density of 10 fish/m3, 0.9 g/day in 30 fish/m3 and 0.4 g/day in 75 fish/m3. This information could be useful for production purposes in this type of systems.展开更多
Sex determination and differentiation play crucial biological roles in sexual reproduction in vertebrates,including zebrafish.Nevertheless,the intricate molecular mechanisms governing these processes have remained eni...Sex determination and differentiation play crucial biological roles in sexual reproduction in vertebrates,including zebrafish.Nevertheless,the intricate molecular mechanisms governing these processes have remained enigmatic.In this study,we showed a pivotal role played by zinc finger GATA-like protein-1(Zglp-1)in sex differentiation in zebrafish.Our findings revealed that homozygous mutants having no Zglp-1 exhibited a female-to-male sex reversal,ultimately resulting in the development of fertile males.Within the pivotal phase of sexual differentiation,zglp-1^(−/−) zebrafish demonstrated a gene expression pattern that was skewed toward a male phenotype.Notably,the expression of amh was upregulated,while the expression of cyp19a1a was not sustained.Furthermore,our data revealed a direct interaction between the zinc fingers of Zglp-1 and Sf-1,which inhibited the ability of Sf-1 to activate the amh promoter.This interaction was crucial for regulating sex differentiation.Moreover,we observed alterations in gonadal cell proliferation and apoptosis in zglp-1^(−/−) zebrafish,which partially contributed to the sexual fate selection.Overall,our findings firmly established Zglp-1 as a crucial regulator of sex differentiation in zebrafish,offering deep insights into the intricate molecular mechanisms that govern sex determination and differentiation in vertebrates.展开更多
Sex reversal is a complex biological phenomenon that occurs in Cynoglossus semilaevis.Some genetic females may irreversibly convert to pseudomales,thus increasing aquaculture costs because males grow much more slowly ...Sex reversal is a complex biological phenomenon that occurs in Cynoglossus semilaevis.Some genetic females may irreversibly convert to pseudomales,thus increasing aquaculture costs because males grow much more slowly than females.In recent years,our studies have shown that genetic background is the primary factor contributing to sex reversal in tongue sole,and two linked loci on the Z chromosome were found to be associated with sex reversal.However,the role of epigenetics in sex reversal and temperature-independent sex determination has yet to be determined.In this study,we used reduced representation bisulfite sequencing(RRBS)to investigate the differences in methylation among female,male and pseudomale tongue sole and explored the possible pattern of DNA methylation associated with sex differentiation and sex reversal.A total of 32200,341115 and 2691 DMRs with average lengths of 163.45,170.15 and 128.77 bp,respectively,were identified between pseudomales and females,males and females,and pseudomales and males.Notably,the sex chromosome(Chr.Z)contained the greatest number of DMRs(303)between pseudomales and males.All the DMGs in each pairwise comparison were enriched in ubiquitin-mediated proteolysis,biosynthesis of secondary metabolites,thermogenesis and metabolic pathways,etc.In addition,differentially methylated genes possibly related to sex differentiation,such as dmrt1,nobox,foxl2,pdgfrb,rspo1,lhx9,emx2,arx,and piwil2,were screened.Methylation differential genes and metabolic pathways associated with sex differentiation have been identified,suggesting the vital role of methylation in gender reversal and sex determination.This study provides valuable insight into epigenetic mechanisms involved in sex differentiation and sex reversal in C.semilaevis.展开更多
Aquaculture is one of the most efficient modes of animal protein production and plays an important role in global food security.Aquaculture animals exhibit extraordinarily diverse sexual phenotypes and underlying mech...Aquaculture is one of the most efficient modes of animal protein production and plays an important role in global food security.Aquaculture animals exhibit extraordinarily diverse sexual phenotypes and underlying mechanisms,providing an ideal system to perform sex determination research,one of the important areas in life science.Moreover,sex is also one of the most valuable traits because sexual dimorphism in growth,size,and other economic characteristics commonly exist in aquaculture animals.Here,we synthesize current knowledge of sex determination mechanisms,sex chromosome evolution,reproduction strategies,and sexual dimorphism,and also review several approaches for sex control in aquaculture animals,including artificial gynogenesis,application of sex-specific or sex chromosome-linked markers,artificial sex reversal,as well as gene editing.We anticipate that better understanding of sex determination mechanisms and innovation of sex control approaches will facilitate sustainable development of aquaculture.展开更多
Female-to-male sex reversals(pseudomales)are common in lower vertebrates and have been found in natural populations,which is a concern under rapid changes in environmental conditions.Pseudomales can exhibit altered sp...Female-to-male sex reversals(pseudomales)are common in lower vertebrates and have been found in natural populations,which is a concern under rapid changes in environmental conditions.Pseudomales can exhibit altered spermatogenesis.However,the regulatory mechanisms underlying pseudomale spermatogenesis remain unclear.Here,we characterized spermatogenesis in Chinese tongue sole(Cynoglossus semilaevis),a species with genetic and environmental sex determination,based on a highresolution single-cell RNA-seq atlas of cells derived from the testes of genotypic males and pseudomales.We identified five germ cell types and six somatic cell types and obtained a single-cell atlas of dynamic changes in gene expression during spermatogenesis in Chinese tongue sole,including alterations in pseudomales.We detected decreased levels of Ca^(2+)signaling pathway-related genes in spermatogonia,insufficient meiotic initiation in spermatocytes,and a malfunction of somatic niche cells in pseudomales.However,a cluster of CaSR genes and MAPK signaling factors were upregulated in undifferentiated spermatogonia of pseudomales.Additionally,we revealed that Z chromosome-specific genes,such as piwil2,dhx37,and ehmt1,were important for spermatogenesis.These results improve our understanding of reproduction after female-to-male sex-reversal and provide new insights into the adaptability of reproductive strategies in lower vertebrates.展开更多
Sex reversal,representing extraordinary sexual plasticity during the life cycle,not only triggers reproduction in animals but also affects reproductive and endocrine system-related diseases and cancers in humans.Sex r...Sex reversal,representing extraordinary sexual plasticity during the life cycle,not only triggers reproduction in animals but also affects reproductive and endocrine system-related diseases and cancers in humans.Sex reversal has been broadly reported in animals;however,an integrated resource hub of sex reversal information is still lacking.Here,we constructed a comprehensive database named ASER(Animal Sex Reversal)by integrating sex reversal-related data of 18 species from teleostei to mammalia.We systematically collected 40,018 published papers and mined the sex reversal-associated genes(SRGs),including their regulatory networks,from 1611 core papers.We annotated homologous genes and computed conservation scores for whole genomes across the 18 species.Furthermore,we collected available RNA-seq datasets and investigated the expression dynamics of SRGs during sex reversal or sex determination processes.In addition,we manually annotated 550 in situ hybridization(ISH),fluorescence in situ hybridization(FISH),and im-munohistochemistry(IHC)images of SRGs from the literature and described their spatial expression in the gonads.Collectively,ASER provides a unique and integrated resource for researchers to query and reuse organized data to explore the mechanisms and applications of SRGs in animal breeding and human health.The ASER database is publicly available at http://aser.ihb.ac.cn/.展开更多
Sex reversal is one of the characteristic properties of sexual plasticity in bony fishes wherein both natural and induced sex change happens at various stages of life cycle in different species.Sex determination in go...Sex reversal is one of the characteristic properties of sexual plasticity in bony fishes wherein both natural and induced sex change happens at various stages of life cycle in different species.Sex determination in gonochoristic species is genetically regulated,wherein the same sex is retained throughout their life span whereas hermaphrodites change their sex during development or adulthood.In sequential hermaphrodites,serial sex change occurs at different points of life cycle.Concurrently,synchronous hermaphrodites function as both the sexes during spawning.Other variables like temperature,pH and social factors can trigger sex reversal in teleost.Sex reversal through gene mutations and chemicals/hormones,including sex steroids,can be induced mostly at early developmental stages but natural sex reversal can occur at any time.Sex reversal mechanism shows morphological to molecular changes,which are ideal for identification of sex-specific gene markers.In fact,gonadal transdifferentiation occurs at the molecular level through differential expression of transcription factors and steroidogenic enzyme genes vis-a-vis hormones,thereby imparting phenotypic or structural changes.In addition,brain shows sexual dimorphism which is mostly consequential to gonadal sex development and occasionally either causative.The major breakthrough in this line is the identification of sex determining genes such as dmy/dmrt1Yb,gsdfY,sox3 in the Japanese medaka and amhY in Patagonian pejerrey.Incidentally,the induction of mono-sex population by favouring one sex due to sex-specific differences in growth is an important economic boom for aquaculture.This review comprehensively highlights key molecular factors involved in natural and induced sex reversal conditions to illustrate teleostean sexual plasticity and its application perspectives.展开更多
The male giant freshwater prawn(Macrobrachium rosenbergii)generally exhibit faster growth rates compared to females of similar age.Consequently,the practice of culturing monosex(all-male)prawn can increase both the pr...The male giant freshwater prawn(Macrobrachium rosenbergii)generally exhibit faster growth rates compared to females of similar age.Consequently,the practice of culturing monosex(all-male)prawn can increase both the production yield and income.Manually selecting males for culture during the grow-out period has long been practiced in commercial prawn farming,but is labor-intensive and generally unsuccessful in producing a male monoculture.The androgenic gland(AG)is essential for sexual differentiation in prawn and development of male primary and secondary sexual characteristics.Microsurgical removal of the AG(andrectomy)from male prawn at an early development stage will transform the male into a fully-functioning neo-female.The M.rosenbergii androgenic gland-specific insulin-like hormone(Mr-IAG)plays critical roles in male spermatogenesis and male sexual development.RNA interference(RNAi)is a highly specific post-transcriptional interference or silencing of gene expression in cells.Silencing Mr-IAG had induced full and functional sex reversal of male to neo-female(genetic male with a female phenotype).Microsurgical removal of AG and RNAi are two different approaches to producing neo-females and both methods target the manipulation of AG for efficient sex-reversal.Neo-females can mate with normal males to produce all-male prawn progeny,which can be used for commercial prawn farming and to improve production efficiency and profitability.This article reviewed recent research related to the development and functions of AG and the testis and their interactions with morphological differentiation at various stages for male M.rosenbergii,aiming to increase understanding on this topic and facilitate discovery of new techniques for advancing M.rosenbergii aquaculture.展开更多
文摘SRY (sex-determining region Y chromosome) is considered as a strong candidste for the TDF (testis determining factor) and has been cloned following another candidate ZFY (zinc finger protein gene). In this study,eight cases of sex revelsal, including four 46, XX males and four 46, XY females aere examined for the presence of SRY sequence and a Y-repeated DNA locus. Our data indicated that the genownic DNA of the four classical 46,XX males had the SRY sequences. On the other hand, both SRY sequences and Ye repeated DNA sequences were present in all four 46, XY females.These resultssuavest that SAY sequences were responsible for the sexraversal of 46, XX males Whereas there may be other genetic mechanisms forthe sex reversal of 46, XY females Without the lack of SRY sequences.
基金supported in parts by the National High Technology R&D Program of China(2006AA10A121)the National Natural Science Foundation of China(30901017)the China Postdoctoral Science Foundation(20100480837,201104387)
文摘Fadrozole, an aromatase inhibitor, can masculinize genetic female chickens and high-dose decreases the hatchability. Therefore, it is important to study the growth and development of sex-reversed females after hatch. Chick embryos from a population of CAU3 egg-type were treated with different concentrations of Fadrozole prior to the sexual differentiation at E3.0 （st18）. At hatch, the phenotypic sex and genetic sex were identified by vent sexing and genetic diagnosis with CHD1, respectively. Body weight and shank length of sex reversal were tested at 8 and 20 wk, respectively. Testicular development, oviduct and ovarian degeneration were observed and serum concentration of estradiol and testosterone were tested with radioimmunoassay （RIA） at 30 wk. The results showed that body weight and shank length of sex- reversed females were not significantly different between low-dose groups （0.1, 0.3, and 0.5 mg for F1, F2, and F3, respectively） and high-dose groups （1.0 and 1.3 mg for F4 and F5, respectively） （P〉0.05）. Left and right testes or ovotestes in F2, F3, F4, and F5 groups were heavier than that of in F1 group （P〈0.05）. While the gonad weight of treatment groups were less than that in male control （P〈0.05）, oviduct weight in F2, F3, F4, and F5 groups were significant differences compared with female control and F1 group （P〈0.05）. Egg number from onset of laying egg to 30 wk in F4 and F5 groups were less than in female control, F1 and F2 groups （P〈0.05）. Serum testosterone level in F5 group was significant higher compared with female control, F1, F2, F3, and F4 groups （P〈0.05）, but significant lower compared with male control （P〈0.05）. While concentration of serum estradiol in F5 group was significant lower compared with female control, F1, F2, and F4 groups （P〈0.05）. In conclusion, the concentration of Fadrozole do not affect postnatal growth of sex-reversed female chicken and the degree of sex-reversed females elevate with the increase of Fadrozole concentration at sex maturity.
文摘Disorders of sex development often arise from anomalies in the molecular or cellular networks that guide the differentiation of the embryonic gonad into either a testis or an ovary, two functionally distinct organs. The activation of the Y-linked gene Sry （sex- determining region Y） and its downstream target Sox9 （Sry box-containing gene 9） triggers testis differentiation by stimulating the differentiation of Sertoli cells, which then direct testis morphogenesis. Once engaged, a genetic pathway promotes the testis development while actively suppressing genes involved in ovarian development. This review focuses on the events of testis determination and the struggle to maintain male fate in the face of antagonistic pressure from the underlying female programme.
文摘The sexual differentiation of germ cells into spermatozoa or oocytes is strictly regulated by their gonadal environment, testis or ovary, which is determined by the presence or absence of the Y chromosome, respectively. Hence, in normal mammalian development, male germ cells differentiate in the presence of X and Y chromosomes, and female germ cells do so in the presence of two X chromosomes. However, gonadal sex reversal occurs in humans as well as in other mammalian species, and the resultant XX males and XY females can lead healthy lives, except for a complete or partial loss of fertility. Germ cells carrying an abnormal set of sex chromosomes are efficiently eliminated by multilayered surveillance mechanisms in the testis, and also, though more variably, in the ovary. Studying the molecular basis for sex-specific responses to a set of sex chromosomes during gametogenesis will promote our understanding of meiotic processes contributing to the evolution of sex determining mechanisms. This review discusses the fate of germ cells carrying various sex chromosomal compositions in mouse models, the limitation of which may be overcome by recent successes in the differentiation of functional germ cells from embryonic stem cells under experimental conditions.
基金supported by the National Key Technology R&D Program of China (2007BAD72B01)the National High Technology R&D Program of China (2011AA100306)
文摘Sex emerges out of a delicate dance between a variety of promale, anti-male, and possibly profemale genes. To investigate the role that sex-related genes play in sex determination and gonadal differentiation of fowl, we constructed a male-to- female sex-reversal model of chick induced by diethylstilbestrol （DES） at onset of incubation （E0）. The results of semi- quantitative PCR showed that the expression of Sf1, the orphan nuclear receptor steroidogenic factor-1 gene, was put forward from E7d to E5d and up-regulated during E5-7d; the Dmrt1, the double sex and the Mab-3 related to transcription factor 1 gene, was down-regulated during E3-7d. Meanwhile, anti-Müllerian hormone gene （Amh） expressed at a similar level in the genetic females and sex-reversal females before E7d, while no expression products of the three female-specific genes Wpkci, Fet1 and Foxl2 were detected in male-to-female embryos. These findings suggest that the expression of some certain sex-related genes, induced by the exogenous estrogen during period of sex determination and gonadal differentiation, results in the male-to-female sex reversal. Moreover, high activity of Sf1 gene during E5-7d might be related to the profemale process, while low activity of Dmrt1 gene during E3-5d might be anti-male. The expression activity of Amh gene might only contribute to the promale process after E7d, however, it is possibly not an anti-female gene in chick embryos.
文摘In sex role reversed species, predominantly females evolve sexually selected traits, such as ornaments and/or weapons. Female ornaments are common and their function well documented in many species, whether sex role reversed or not. However, sexually selected female weapons seem totally absent except for small wing spurs in three jacana species, present in both males and females. This poor female weaponry is in sharp contrast to the situation in species with conventional sex roles： males com- monly have evolved sexually selected weapons as well as ornaments. At the same time, females in many taxa have naturally se- lected weapons, used in competition over resources or in predator defence. Why are sexually selected weapons then so rare, al- most absent, in females？ Here I briefly review weaponry in females and the function of these weapons, conclude that the near ab- sence of sexually selected weapons begs an explanation, and suggest that costs of sexually selected weapons may exceed costs of ornaments. Females are more constrained when evolving sexually selected traits compared to males, at least compared to those males that do not provide direct benefits, as trait costs reduce a female＇s fecundity. I suggest that this constraining trade-off between trait and fecundity restricts females to evolve ornaments but rarely weapons. The same may apply to paternally investing males. Whether sexually selected weapons actually are more costly than sexually selected ornaments remains to be investigated
基金supported by grants from the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB31000000)the Second Tibetan Plateau Scientific Expedition and Research Program(STEP)(2019QZKK0501)Joint Grant from Chinese Academy of Sciences-People’s Government of Qinghai Province on Sanjiangyuan National Park(LHZX-2020-01)。
文摘Sex-determining systems show a striking diversity not only among species, but also among popula tions. In reptiles, sex-determina tion is a continuum, from tempera ture-dependent sex determination(TSD) to genetic sex determination(GSD).The multi-ocellated racerunner(Eremias multiocellata)is reported to be a cryptic ZZ/ZW chromosomal TSD species, with male-biased sex ratios at high temperatures in two Gansu populations. However, the generality of the sex-determining pattern in different populations of this species remains unclear. To investigate the mode of sex determina tion in a popula tion of E.multiocellata from the desert steppe of Inner Mongolia,we first identified sex chromosomes via comparative genomic hybridization(CGH). We then conducted a thermal manipulation experiment to determine the effect of gestation temperature on offspring sex ratios.From the CGH studies we found that lizards from the Inner Mongolia population possessed ZZ/ZW sex chromosomes. However, our thermal manipulation experiment showed that gestation temperature did not affect the sex ratio of neonates in this population. In combination, these results rule out TSD in the Inner Mongolia population of E. multiocellata, and suggest that there is widespread geographic variation in the sexdetermining system of this species.
基金supported by the National Natural Science Foundation of China(32325049,U22A20529,32303000)Zhejiang Provincial Natural Science Foundation(LQ24C190009)+1 种基金Ningbo Natural Science Foundation(2022J192)Zhejiang Provincial Top Key Discipline of Biological Engineering(1741000592)。
文摘In reptiles,such as the red-eared slider turtle(Trachemys scripta elegans),gonadal sex determination is highly dependent on the environmental temperature during embryonic stages.This complex process,which leads to differentiation into either testes or ovaries,is governed by the finely tuned expression of upstream genes,notably the testis-promoting gene Dmrt1 and the ovary-promoting gene Foxl2.Recent studies have identified epigenetic regulation as a crucial factor in testis development,with the H3K27me3 demethylase KDM6B being essential for Dmrt1 expression in T.s.elegans.However,whether KDM6B alone can induce testicular differentiation remains unclear.In this study,we found that overexpression of Kdm6b in T.s.elegans embryos induced the male development pathway,accompanied by a rapid increase in the gonadal expression of Dmrt1 at 31°C,a temperature typically resulting in female development.Notably,this sex reversal could be entirely rescued by Dmrt1 knockdown.These findings demonstrate that Kdm6b is sufficient for commitment to the male pathway,underscoring its role as a critical epigenetic regulator in the sex determination of the red-eared slider turtle.
文摘This study was conducted to determine the effective dose of 17α-methyltestosterone(MT)that produces all-male fry of black-chinned tilapia,Sarotherodon melanotheron.Five concentrations:0,30,60,90 and 120 mg 17α-methyltestosterone(17α-MT)per kilogram feed were prepared using the ethanol evaporation method,and administered orally to black-chinned tilapia fry for 28 days in triplicate aquarium glass tanks.After the treatment period,triplicates of 60 fry from each treatment were stocked in hapas and further cultured in freshwater ponds.They were fed with commercial fish feed ad libitum.The sex ratio,growth performance and survival were evaluated after 60 and 180 days.At the end of the 60-day period,the sex ratio of 30 fish from each treatment was determined by using the gonadal squash method.The remaining 30 fish from each treatment were grown further for 180 days and their sex ratio determined using the genital papillae.The results demonstrated that 17α-methyltestosterone was effective in producing phenotypic male in S.melanotheron.However,in both 60-day and 180-day experiments,no treatment gave 100%male population.The 90 mg/kg MT yielded the highest all-male fish of 84.13%,highest survival of 70%and highest final mean body weight of 103.99±7.92 g.
基金Supported by the China Agriculture Research System(No.CARS-50-G20)the National Natural Science Foundation of China(No.31402284)the National High Technology Research and Development Program of China(863 Program)(No.2012AA10A413-2)
文摘The aim of the present study was to investigate the long-term effects of 17l）-estradiol （E2） exposure on gonadal development in the tiger puffer （Taktfugu rubripes）, which has a genetic sex determination system of male homogametic XY-XX. Tiger puffer larvae were exposed to 1, 10 and 100 μg/L E2 from 15 to 100 days post-hatch （dph） and then maintained in clean seawater until 400 dph. Changes in sex ratio, gonadal structure and gonadosomatic index （GSI） were monitored at 100, 160, 270 and 400 dph. Sex-associated single nucleotide polymorphism （SNP） markers were used to analyze the genetic sex of samples, except those at 100 dph. Exposure had a positive effect on the conversion of genetically male gonads into phenotypically female gonads at 100 dph. However, gonads from 60% of genetic XY males in the 1-μg/L E2 group and 100% in the 10-μg/L E2 group developed intersexual gonads at 160 dph; gonads of all genetic XY males in the two treatment groups reverted to testis by 270 dph. While 38%, 57% and 44% of gonads of XY fish in the 100-gg/L E2 group reverted to intersexual gonads at 160, 270 and 400 dph, respectively, none reverted to testis after E2 treatment. In addition, E2 exposure inhibited gonadal growth of both genetic sexes, as indicated by the clear dose-dependent decrease in GSI at 270 and 400 dph. The results showed that exposure to E2 during the early life stages of tiger puffer disrupted gonadal development, but that fish recovered after migration to clean seawater. The study suggests the potential use of tiger puffer as a valuable indicator species to evaluate the effects of environmental estrogens on marine fish, thereby protecting valuable fishery resources.
文摘Intersexualism occurs in all species of maxnmals and the pathogenesis of abnormal development of the gonads is still unclear. Thus, the aim of this report is to describe the hormonal and histopathological findings from a case of bilateral true hermaphroditism in a mixed-breed bitch due to the few case reports published involving hormonal levels in dogs with intersexuality. Serum was obtained from the animal before surgery and was submitted to hormone measurements. Progesterone and testosterone were evaluated by radioimnunoassay and estrogen by ELISA （immune-enzymatic assay）. The values of progesterone, testosterone and estrogen concentrations were 2.26 ng/mL, 0.05 ng/mL and 9.7 pg/mL, respectively. The proportion of ovarian tissue found in the ovotestes after histopathological examination was higher in relation to seminiferous tubules, which may explain the low level of serum testosterone. Low concentration of serum testosterone may have contributed to the partial virilization of external genitalia, since the animal only had clitoral hypertrophy. Estrogen and progesterone levels found were compatible with the initial stage of estrus （preovulatory LH （luteinizing hormone） surge）, which shows that ovarian follicles found in the bilateral ovotestes contributed to the occurrence of the estrous cycle before surgery. Quantitation of serum hormones may also shed light on the cause of disturbances in sex differentiation in canine species. More studies are needed to elucidate the real cause of intersex in dogs.
基金supported by the National Key Research and Development Program of China(2022YFD2400101)to Y.S.
文摘The ricefield eel(Monopterus albus),a protogynous hermaphrodite,is an important aquaculture freshwater fish in China.Intensive studies have focused on the sex reversal of this species,but the underlying mechanisms remain elusive.We performed comparative transcriptome analysis for gonadal tissues of female,intersex,and male ricefield eels.The results suggest that temperature may play a role in inducing the sex reversal.Moreover,an epithelial-mesenchymal transition(EMT)gene signature was found,suggesting an involvement of germinal epithelium in contributing to gonadal transformation.Our in vitro and in vivo experiments show that thermal cues are sensed by thermosensors such as Trpv4 in the gonadal cells of ricefield eels,which can be transduced to the sex determination cascades.The epithelial cells of germinal epithelium can become Sertoli cells via an EMT.Our study provides new insights into the molecular mechanisms underlying the sex reversal of ricefield eels.
基金Financial support was provided by the Division de Ciencias Biologicas y de la Salud,UAM-Iztapalapa.
文摘We present results of a long-term study aimed to optimize Nile tilapia O. niloticus production in a recirculating aquaculture system (RAS) in México City. Three experiments were evaluated: 1) fry production;2) production of masculinized fries;and 3) assessment of growth under three different densities (10, 30 and 75 fish/m3). The broodstock produced on average 2400 ± 600 fry every 15 days during six months, with a total production of 28,800 ± 2000. One hundred percent males were produced in 274-L raceways in an eight-week period. The obtained results in fish production in the RAS system indicated variations related to density. A daily growth rate of 3.6 g/day was registered with a density of 10 fish/m3, 0.9 g/day in 30 fish/m3 and 0.4 g/day in 75 fish/m3. This information could be useful for production purposes in this type of systems.
基金supported by the grants of the National Key Research and Development Project of the Ministry of Science and Technology(2023YFE0199500)Shandong Provincial Natural Science Foundation(ZR2022MC032)Science&Tech-nology Innovation Project of Laoshan Laboratory(LSKJ202203204)。
文摘Sex determination and differentiation play crucial biological roles in sexual reproduction in vertebrates,including zebrafish.Nevertheless,the intricate molecular mechanisms governing these processes have remained enigmatic.In this study,we showed a pivotal role played by zinc finger GATA-like protein-1(Zglp-1)in sex differentiation in zebrafish.Our findings revealed that homozygous mutants having no Zglp-1 exhibited a female-to-male sex reversal,ultimately resulting in the development of fertile males.Within the pivotal phase of sexual differentiation,zglp-1^(−/−) zebrafish demonstrated a gene expression pattern that was skewed toward a male phenotype.Notably,the expression of amh was upregulated,while the expression of cyp19a1a was not sustained.Furthermore,our data revealed a direct interaction between the zinc fingers of Zglp-1 and Sf-1,which inhibited the ability of Sf-1 to activate the amh promoter.This interaction was crucial for regulating sex differentiation.Moreover,we observed alterations in gonadal cell proliferation and apoptosis in zglp-1^(−/−) zebrafish,which partially contributed to the sexual fate selection.Overall,our findings firmly established Zglp-1 as a crucial regulator of sex differentiation in zebrafish,offering deep insights into the intricate molecular mechanisms that govern sex determination and differentiation in vertebrates.
基金supported financially by the National Key Research and Development Program,China(2022YFD2400405)Special Scientific Research Funds for Central Nonprofit Institutes,Chinese Academy of Fishery Sciences,China(2023TD25).
文摘Sex reversal is a complex biological phenomenon that occurs in Cynoglossus semilaevis.Some genetic females may irreversibly convert to pseudomales,thus increasing aquaculture costs because males grow much more slowly than females.In recent years,our studies have shown that genetic background is the primary factor contributing to sex reversal in tongue sole,and two linked loci on the Z chromosome were found to be associated with sex reversal.However,the role of epigenetics in sex reversal and temperature-independent sex determination has yet to be determined.In this study,we used reduced representation bisulfite sequencing(RRBS)to investigate the differences in methylation among female,male and pseudomale tongue sole and explored the possible pattern of DNA methylation associated with sex differentiation and sex reversal.A total of 32200,341115 and 2691 DMRs with average lengths of 163.45,170.15 and 128.77 bp,respectively,were identified between pseudomales and females,males and females,and pseudomales and males.Notably,the sex chromosome(Chr.Z)contained the greatest number of DMRs(303)between pseudomales and males.All the DMGs in each pairwise comparison were enriched in ubiquitin-mediated proteolysis,biosynthesis of secondary metabolites,thermogenesis and metabolic pathways,etc.In addition,differentially methylated genes possibly related to sex differentiation,such as dmrt1,nobox,foxl2,pdgfrb,rspo1,lhx9,emx2,arx,and piwil2,were screened.Methylation differential genes and metabolic pathways associated with sex differentiation have been identified,suggesting the vital role of methylation in gender reversal and sex determination.This study provides valuable insight into epigenetic mechanisms involved in sex differentiation and sex reversal in C.semilaevis.
基金supported by the Key Program of Frontier Sciences of the Chinese Academy of Sciences(QYZDY-SSWSMC025)the Strategic Priority Research Program of Chinese Academy of Sciences(XDB31000000)+5 种基金the National Natural Science Foundation of China(31873036,32072958,31922084,31872960,32102789)the National Key Research and Development Project(2018YFD0900204,2018YFD0901201,2018YFD0900203,2018YFD0900201)the Consulting Research Projects of Hubei Institute of Chinese Engineering Development Strategies and Academic Divisions of the Chinese Academy of Sciences(2021-SM02-B-010)the China Agriculture Research System of MOF and MARA(CARS-45-07 and CARS-46)the Autonomous Project of the State Key Laboratory of Freshwater Ecology and Biotechnology(2019FBZ04)the Youth Innovation Promotion Association CAS(2020334)。
文摘Aquaculture is one of the most efficient modes of animal protein production and plays an important role in global food security.Aquaculture animals exhibit extraordinarily diverse sexual phenotypes and underlying mechanisms,providing an ideal system to perform sex determination research,one of the important areas in life science.Moreover,sex is also one of the most valuable traits because sexual dimorphism in growth,size,and other economic characteristics commonly exist in aquaculture animals.Here,we synthesize current knowledge of sex determination mechanisms,sex chromosome evolution,reproduction strategies,and sexual dimorphism,and also review several approaches for sex control in aquaculture animals,including artificial gynogenesis,application of sex-specific or sex chromosome-linked markers,artificial sex reversal,as well as gene editing.We anticipate that better understanding of sex determination mechanisms and innovation of sex control approaches will facilitate sustainable development of aquaculture.
基金supported by the National Key R&D Program of China(2018YFD0900301)the National Nature Science Foundation of China(31722058,31802275,31472269)+4 种基金the AoShan Talents Cultivation Program Supported by Qingdao National Laboratory for Marine Science and Technology(2017ASTCP-ES06)the Taishan Scholar Project Fund of Shandong of China to C.S.the National Ten-Thousands Talents Special Support Program to C.S.the Central Public-interest Scientific Institution Basal Research Fund,CAFS(2020TD19)the China Agriculture Research System(CARS-47-G03)。
文摘Female-to-male sex reversals(pseudomales)are common in lower vertebrates and have been found in natural populations,which is a concern under rapid changes in environmental conditions.Pseudomales can exhibit altered spermatogenesis.However,the regulatory mechanisms underlying pseudomale spermatogenesis remain unclear.Here,we characterized spermatogenesis in Chinese tongue sole(Cynoglossus semilaevis),a species with genetic and environmental sex determination,based on a highresolution single-cell RNA-seq atlas of cells derived from the testes of genotypic males and pseudomales.We identified five germ cell types and six somatic cell types and obtained a single-cell atlas of dynamic changes in gene expression during spermatogenesis in Chinese tongue sole,including alterations in pseudomales.We detected decreased levels of Ca^(2+)signaling pathway-related genes in spermatogonia,insufficient meiotic initiation in spermatocytes,and a malfunction of somatic niche cells in pseudomales.However,a cluster of CaSR genes and MAPK signaling factors were upregulated in undifferentiated spermatogonia of pseudomales.Additionally,we revealed that Z chromosome-specific genes,such as piwil2,dhx37,and ehmt1,were important for spermatogenesis.These results improve our understanding of reproduction after female-to-male sex-reversal and provide new insights into the adaptability of reproductive strategies in lower vertebrates.
基金supported by grants from the National Natural Science Foundation of China(Grant Nos.31922085,31872191 to DL,Grant No.31922039 to YZ)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDA24010108 to WH and DL)+1 种基金the China Agriculture Research System of Ministry of Finance(MOF)and Ministry of Agriculture and Rural Affairs(MARA)(Grant No.CARS-46 to WH)the Natural Science Foundation of Hubei Province,China(Grant No.2020CFA056 to DL,Grant No.2020CFA057 to YZ).
文摘Sex reversal,representing extraordinary sexual plasticity during the life cycle,not only triggers reproduction in animals but also affects reproductive and endocrine system-related diseases and cancers in humans.Sex reversal has been broadly reported in animals;however,an integrated resource hub of sex reversal information is still lacking.Here,we constructed a comprehensive database named ASER(Animal Sex Reversal)by integrating sex reversal-related data of 18 species from teleostei to mammalia.We systematically collected 40,018 published papers and mined the sex reversal-associated genes(SRGs),including their regulatory networks,from 1611 core papers.We annotated homologous genes and computed conservation scores for whole genomes across the 18 species.Furthermore,we collected available RNA-seq datasets and investigated the expression dynamics of SRGs during sex reversal or sex determination processes.In addition,we manually annotated 550 in situ hybridization(ISH),fluorescence in situ hybridization(FISH),and im-munohistochemistry(IHC)images of SRGs from the literature and described their spatial expression in the gonads.Collectively,ASER provides a unique and integrated resource for researchers to query and reuse organized data to explore the mechanisms and applications of SRGs in animal breeding and human health.The ASER database is publicly available at http://aser.ihb.ac.cn/.
基金The research work mentioned in this review was supported by grant-in-aid(Ref.No.EMR/2017/000718)from the Science and Engineering Research BoardIndia to BS.ST is thankful to Senior Research Fellowship support by Council of Scientific and Industrial Research(Ref.No.09/414(1150)/2017-EMR-I)India.Authors acknowledge BUILDER Grant from DBT(Ref.No.BUILDER-DBT-BT/INF/22/SP41176/2020),India to School of Life Sciences,University of Hyderabad.
文摘Sex reversal is one of the characteristic properties of sexual plasticity in bony fishes wherein both natural and induced sex change happens at various stages of life cycle in different species.Sex determination in gonochoristic species is genetically regulated,wherein the same sex is retained throughout their life span whereas hermaphrodites change their sex during development or adulthood.In sequential hermaphrodites,serial sex change occurs at different points of life cycle.Concurrently,synchronous hermaphrodites function as both the sexes during spawning.Other variables like temperature,pH and social factors can trigger sex reversal in teleost.Sex reversal through gene mutations and chemicals/hormones,including sex steroids,can be induced mostly at early developmental stages but natural sex reversal can occur at any time.Sex reversal mechanism shows morphological to molecular changes,which are ideal for identification of sex-specific gene markers.In fact,gonadal transdifferentiation occurs at the molecular level through differential expression of transcription factors and steroidogenic enzyme genes vis-a-vis hormones,thereby imparting phenotypic or structural changes.In addition,brain shows sexual dimorphism which is mostly consequential to gonadal sex development and occasionally either causative.The major breakthrough in this line is the identification of sex determining genes such as dmy/dmrt1Yb,gsdfY,sox3 in the Japanese medaka and amhY in Patagonian pejerrey.Incidentally,the induction of mono-sex population by favouring one sex due to sex-specific differences in growth is an important economic boom for aquaculture.This review comprehensively highlights key molecular factors involved in natural and induced sex reversal conditions to illustrate teleostean sexual plasticity and its application perspectives.
文摘The male giant freshwater prawn(Macrobrachium rosenbergii)generally exhibit faster growth rates compared to females of similar age.Consequently,the practice of culturing monosex(all-male)prawn can increase both the production yield and income.Manually selecting males for culture during the grow-out period has long been practiced in commercial prawn farming,but is labor-intensive and generally unsuccessful in producing a male monoculture.The androgenic gland(AG)is essential for sexual differentiation in prawn and development of male primary and secondary sexual characteristics.Microsurgical removal of the AG(andrectomy)from male prawn at an early development stage will transform the male into a fully-functioning neo-female.The M.rosenbergii androgenic gland-specific insulin-like hormone(Mr-IAG)plays critical roles in male spermatogenesis and male sexual development.RNA interference(RNAi)is a highly specific post-transcriptional interference or silencing of gene expression in cells.Silencing Mr-IAG had induced full and functional sex reversal of male to neo-female(genetic male with a female phenotype).Microsurgical removal of AG and RNAi are two different approaches to producing neo-females and both methods target the manipulation of AG for efficient sex-reversal.Neo-females can mate with normal males to produce all-male prawn progeny,which can be used for commercial prawn farming and to improve production efficiency and profitability.This article reviewed recent research related to the development and functions of AG and the testis and their interactions with morphological differentiation at various stages for male M.rosenbergii,aiming to increase understanding on this topic and facilitate discovery of new techniques for advancing M.rosenbergii aquaculture.
