Abstract
The cyp19a1 gene codes aromatase that converts androgen to estrogen, which plays a central role in early female differentiation and ovarian development in teleosts. For the blotched snakehead (Channa maculata), an important aquaculture fish that is susceptible to hormone-induced sex reversal, two aromatase genes were characterized in the present study, cyp19a1a and cyp19a1b. We analyzed gene expression and the epigenetic state of cyp19a1a and cyp19a1b in different adult tissues: the gonad and brain from normal XX females (XX-F), normal XY males (XY-M), sex-reversal females (XY-F) induced by estrogen, and YY super-males (YY-M), and gonads at different development stages. Cyp19a1a exhibited strong female-biased expression patterns in the ovary, and cyp19a1b dominantly expressed in the brain with no sex bias. Cyp19a1a’s expression pattern in the XY-F ovary was similar to that in the XX-F ovary, with a relatively high expression level, which was far higher than that in XY-M and YY-M testis. Meanwhile, CpG methylation levels of cyp19a1a promoter were lower in XX-F and XY-F ovaries compared with XY-M and YY-M testis. A significantly negative correlation between the CpG methylation levels and cyp19a1a expression was elucidated in XX-F, XY-M, XY-F, and YY-M gonads. Furthermore, the strong female-biased cyp19a1a expression was closely related to ovarian differentiation and maturation, and the overall methylation levels of cyp19a1a promoter were inversely correlated with cyp19a1a expression. There were no detectable sexually dimorphic differences in cyp19a1b expression and CpG methylation levels of cyp19a1b promoter in the brain and gonad between sexes in C. maculata, thus the function of cyp19a1b in C. maculata needs further research. Our research illustrates that cyp19a1a is closely related to estrogen production, ovary differentiation/maintenance, and sex reversal, and epigenetic modification plays a crucial part in maintaining the sexual dimorphic expression of cyp19a1a, ovarian differentiation and oogenesis in C. maculata.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.