GATA4 is a transcriptional regulator of R-spondin1 in Japanese flounder (Paralichthys olivaceus)

Abstract GATA4 is a well-known transcription factor of the GATA family implicated in regulation of sex determination and gonadal development in mammals. In this study, we cloned the full-length cDNA of Paralichthys olivaceus gata4 ( Po-gata4 ). Phylogenetic, gene structure, and synteny analysis showed that Po -GATA4 is homologous to GATA4 of teleost and tetrapod. Po - gata4 transcripts were detected in Sertoli cells, spermatogonia, oogonia and oocytes, with higher transcript levels overall in the testis than the ovary. The promoter region of P. olivaceus R-spondin1 was found to contain a GATA4-binding motif. Results of CBA (cleaved amplified polymorphic sequence-based binding assay) indicated that GATA4 could indeed bind to the promoter sequence of R-spondin1 . Moreover, human GATA4 recombinant protein could upregulate R-spondin1 in P. olivaceus ovary cells and FBCs (flounder brain cell line). In FBCs, overexpression of Po - gata4 resulted in elevated transcript levels of R-spondin1 . Taken together, our results indicate that Po -GATA4 is involved in gonadal development by regulating R-spondin1 expression.