背景:斑点蛇头(Channamaculata)表现出明显的性二态性,与女性相比,男性表现出更快的生长速度和更大的体型。全男性蛇头种群的种植具有巨大的经济和生态价值。尽管如此,控制双潜能性腺发育进入睾丸或卵巢的复杂过程。因此,有必要确定黄斑蟹性别分化的关键时间窗,为生产实践中的性别控制提供理论依据。
方法:在不同的发育阶段测量了雄性和雌性C.maculata的身长和体重,以揭示生长中的性二态性最初何时出现。对各个发育阶段的卵巢和睾丸进行了组织学观察和时空比较转录组分析,以确定每种性别和性别相关基因性别分化的关键时间窗口。此外,qPCR和MG2C用于验证和定位性别相关基因,对E2和T的水平进行定量,以了解性类固醇的合成。
结果:从90dpf开始,生长中的性二态性变得明显。组织学观察显示,女性和男性的形态性别分化发生在20至25dpf或更早和30-35dpf或更早之间,分别,对应于卵巢腔或流出管的外观。转录组分析显示,30dpf后,睾丸和卵巢中的基因表达模式不同。40-60dpf和60-90dpf的时期标志着女性和男性分子性别分化的开始,分别。男性偏见基因(Sox11a,Dmrt1,Amh,Amhr2,Gsdf,Ar,Cyp17a2)可能在男性性别分化和精子发生中起关键作用,而女性偏向基因(Foxl2,Cyp19a1a,Bmp15,Figla,Er)可能在卵巢分化和发育中起关键作用。还鉴定了与性别分化和配子发生有关的许多生物学途径。此外,E2和T在性别分化和性腺发育过程中表现出性二态。基于这些结果,假设在C.maculata中,潜在的男性性别分化途径,Sox11a-Dmrt1-Sox9b,激活下游性别相关基因(Amh,Amhr2,Gsdf,Ar,Cyp17a2)用于睾丸发育,而拮抗途径,Foxl2/Cyp19a1a,激活下游性别相关基因(Bmp15,Figla,Er)用于卵巢发育。
结论:本研究全面概述了黄斑梭菌性别分化和配子发生过程中的性腺动态变化,为该物种的性别控制奠定了科学基础。
斑点蛇头(Channamaculata)表现出明显的性二态性,与女性相比,男性表现出更快的生长速度和更大的体型。全男性蛇头种群的种植具有巨大的经济和生态价值。然而,黄斑C的性别决定和分化的潜在机制仍未得到充分阐明。在这项研究中,从90dpf开始,通过测量不同发育阶段的雄性和雌性C.maculata的身长和体重,可以明显看出生长中的性二态性。组织学观察表明,女性和男性的形态性别分化发生在20-25dpf或更早和30-35dpf或更早,分别,对应于卵巢腔或流出管的外观。转录组分析显示30dpf后男性和女性性腺中不同的基因表达模式,这表明30dpf之前的时期可能是黄斑C的性别控制的关键时间窗口。40-60dpf和60-90dpf的时期标志着女性和男性分子性别分化的开始,分别。男性偏见基因(Sox11a,Dmrt1,Amh,Amhr2,Gsdf,Ar,Cyp17a2)可能在睾丸分化和精子发生中起关键作用,而女性偏向基因(Foxl2,Cyp19a1a,Bmp15,Figla,Er)可能在卵巢分化和卵子发生中起关键作用。此外,鉴定了许多与性别分化和配子发生相关的生物学途径。此外,在性腺分化和发育过程中,E2和T水平观察到性二态性。基于这些发现,假设在C.maculata中,潜在的男性性别分化途径,Sox11a-Dmrt1-Sox9b,激活下游性别相关基因(Amh,Amhr2,Gsdf,Ar,Cyp17a2)用于睾丸发育,而拮抗途径,Foxl2/Cyp19a1a,激活下游性别相关基因(Bmp15,Figla,Er)用于卵巢发育。这项研究提供了一个全面的概述,在性别分化和配子发生过程中性腺的动态变化。从而为该物种的性别控制奠定了科学基础。
BACKGROUND: Blotched snakehead (Channa maculata) displays significant sexual dimorphism, with males exhibiting faster growth rates and larger body sizes compared to females. The cultivation of the all-male population of snakeheads holds substantial economic and ecological value. Nonetheless, the intricate processes governing the development of bipotential gonads into either testis or ovary in C. maculata remain inadequately elucidated. Therefore, it is necessary to determine the critical time window of sex differentiation in C. maculata, providing a theoretical basis for sex control in production practices.
METHODS: The body length and weight of male and female C. maculata were measured at different developmental stages to reveal when sexual dimorphism in growth initially appears. Histological observations and spatiotemporal comparative transcriptome analyses were performed on ovaries and testes across various developmental stages to determine the crucial time windows for sex differentiation in each sex and the sex-related genes. Additionally, qPCR and MG2C were utilized to validate and locate sex-related genes, and levels of E2 and T were quantified to understand sex steroid synthesis.
RESULTS: Sexual dimorphism in growth became evident starting from 90 dpf. Histological observations revealed that morphological sex differentiation in females and males occurred between 20 and 25 dpf or earlier and 30-35 dpf or earlier, respectively, corresponding to the appearance of the ovarian cavity or efferent duct anlage. Transcriptome analyses revealed divergent gene expression patterns in testes and ovaries after 30 dpf. The periods of 40-60 dpf and 60-90 dpf marked the initiation of molecular sex differentiation in females and males, respectively. Male-biased genes (Sox11a, Dmrt1, Amh, Amhr2, Gsdf, Ar, Cyp17a2) likely play crucial roles in male sex differentiation and spermatogenesis, while female-biased genes (Foxl2, Cyp19a1a, Bmp15, Figla, Er) could be pivotal in ovarian differentiation and development. Numerous biological pathways linked to sex differentiation and gametogenesis were also identified. Additionally, E2 and T exhibited sexual dimorphism during sex differentiation and gonadal development. Based on these results, it is hypothesized that in C. maculata, the potential male sex differentiation pathway, Sox11a-Dmrt1-Sox9b, activates downstream sex-related genes (Amh, Amhr2, Gsdf, Ar, Cyp17a2) for testicular development, while the antagonistic pathway, Foxl2/Cyp19a1a, activates downstream sex-related genes (Bmp15, Figla, Er) for ovarian development.
CONCLUSIONS: This study provides a comprehensive overview of gonadal dynamic changes during sex differentiation and gametogenesis in C. maculata, establishing a scientific foundation for sex control in this species.
Blotched snakehead (Channa maculata) exhibits significant sexual dimorphism, as males display faster growth rates and larger body sizes compared to females. The cultivation of the all-male population of snakeheads holds substantial economic and ecological value. However, the mechanisms underlying sex determination and differentiation in C. maculata remain insufficiently elucidated. In this study, sexual dimorphism in growth became evident starting from 90 dpf through the measurement of body length and weight of male and female C. maculata at different developmental stages. Histological observations indicated that morphological sex differentiation in females and males occurred at 20–25 dpf or earlier and 30–35 dpf or earlier, respectively, corresponding to the appearance of the ovarian cavity or efferent duct anlage. Transcriptome analyses revealed divergent gene expression patterns in male and female gonads after 30 dpf, suggesting that the period preceding 30 dpf might be the critical time window for sex control in C. maculata. The periods of 40–60 dpf and 60–90 dpf marked the initiation of molecular sex differentiation in females and males, respectively. Male-biased genes (Sox11a, Dmrt1, Amh, Amhr2, Gsdf, Ar, Cyp17a2) likely play crucial roles in testicular differentiation and spermatogenesis, while female-biased genes (Foxl2, Cyp19a1a, Bmp15, Figla, Er) could be pivotal in ovarian differentiation and oogenesis. Additionally, numerous biological pathways linked to sex differentiation and gametogenesis were identified. Moreover, sexual dimorphism was observed in the levels of E2 and T during gonadal differentiation and development. Based on these findings, it is hypothesized that in C. maculata, the potential male sex differentiation pathway, Sox11a–Dmrt1–Sox9b, activates downstream sex-related genes (Amh, Amhr2, Gsdf, Ar, Cyp17a2) for testicular development, while the antagonistic pathway, Foxl2/Cyp19a1a, activates downstream sex-related genes (Bmp15, Figla, Er) for ovarian development. This study provides a comprehensive overview of gonadal dynamic changes during sex differentiation and gametogenesis in C. maculata, thereby establishing a scientific foundation for sex control in this species.