Nomesh Yadu, PhD Student
Retinoic acid has been demonstrated to be the main factor causing the differentiation of SSCs in the mammalian testis. Retinoic acid exerts its effect through many of the receptors present in Sertoli cells and germ cells. RA receptors are broadly catagorised as Retinoic Acid Receptors (RARs) and Rexinoid receptors (RXRs) and both types have been shown to be expressed in the mammalian testis. RARs are of three types, viz, RAR? RAR? and RAR?. RA-dependent events are believed to be mediated predominantly by RA receptor ? (RAR ?) in spermatogonia and by RAR? in Sertoli cells. Recent reports indicate that RAR? may function in Sertoli cells to promote the survival and development of early meiotic prophase spermatocytes, whereas RAR? in germ cells functions to increase the proliferation and differentiation of spermatogonia, prior to meiotic prophase. However, RAR?-dependent pathways operating in Sertoli cells which ultimately affect the germline lineage at various stages of their development are not clear. In this context, we aim to study the specific roles of retinoic acid receptors ? and ? in germ cell differentiation using in vitro culture systems and selective silencing of respective receptor genes.