Cbx2 a PcG Family Gene Plays a Regulatory Role in Medaka Gonadal Development

摘要

Chromobox homolog 2 (CBX2), a key member of the polycomb group (PcG) family, is essential for gonadal development in mammals. A functional deficiency or genetic mutation in can lead to sex reversal in mice and humans. However, little is known about the function of in gonadal development in fish. In this study, the gene was identified in medaka, which is a model species for the study of gonadal development in fish. Transcription of was abundant in the gonads, with testicular levels relatively higher than ovarian levels. In situ hybridization (ISH) revealed that mRNA was predominately localized in spermatogonia and spermatocytes, and was also observed in oocytes at stages I, II, and III. Furthermore, and (a marker gene) were co-localized in germ cells by fluorescent in situ hybridization (FISH). After knockdown in the gonads by RNA interference (RNAi), the sex-related genes, including and were influenced. These results suggest that not only plays a positive role in spermatogenesis and oogenesis but is also involved in gonadal differentiation through regulating the expression levels of sex-related genes in fish.