Expression Analysis Of Dmrt Gene In Gonad And Different Embryonic Development Stages Of Epinephelus Coioides

Epinephelus coioides is a protogynous hermaphrodite marine fish with high economic value in aquaculture.Because of the phenomenon of sex reversal,E.coioides isconsidered to be a good model to study gonad differentiation,sex determination and reproductive control of fish.The Dmrt(Double sex/Male-abnormal-3 Related Transcription factor)gene is the major transcription factor in sex determination and differentiation.The study has found that Dmrt is closely related to the reproductive development and organ development,and dmrt1 is the main concern of the Dmrt gene family and has been studied in different species.This experiment used in situ hybridization and immunohistochemistryto study the expression of dmrt1 in the gonad of E.coioides,RT-qPCR to analyze the effects of four dmrt genes(Ecdmrt1,Ecdmrt2,Ecdmrt2 b and Ecdmrt3)in embryonic development anddifferent gonaddevelopment stages.The results are as follows:During the embryonic development of E.coioides,the dmrt has been expressed.The expression level of Ecdmrt1 gene was the highest in the blastula stage and the lowest expression was in the cleavage stage and the larvae;Ecdmrt2 gene expression was low in the early embryonic development and significantly increased(p<0.05)in neurula stage,Ecdmrt2 mRNApeaked atthe larvae.Ecdmrt2 b mRNA increased at the organogenesis stage,and then decreased(p>0.05);thechanging tendency of Ecdmrt3 expression was the same as Ecdmrt2,and it increased at the organogenesis stage(p>0.05).In the gonad development of E.coioides,Ecdmrt1,Ecdmrt2 b and Ecdmrt3 expressedhighly in the intersex gonad,and Ecdmrt2 geneexpressed highly in II stage ovary.ISH showed that Ecdmrt1 was highly expressed in the testis and was mainly expressed in the spermatocytes,and there was no positive signal found in the sperm and ovary.The immunohistochemistry results showed that Ecdmrt1 protein mainly expressed in grouper testis and located around the spermatocytes,ovary and the control group was not detected.The results showed that Ecdmrt1 was closely related to the development of testis,may be also involved in the development of ovary;dmrt gene may play an important role in E.coioides gonad development.Besides,it may involve in the embryonic organs grow and the development of larvae.