Sex determining genes and sexual differentiation in a marsupial

The role of genes in the differentiation of the testis and ovary has been e xtensively studied in the human and the mouse. Despite over a decade of inv estigations, the precise roles of genes and their interactions in the pathw ay of sex determination are still unclear. We have chosen to take a compara tive look at sex determination and differentiation to gain insights into th e evolution and the conserved functions of these genes. To achieve this, we have examined a wide variety of eutherian sex determining genes in a marsu pial, the tammar wallaby, to determine which genes have a conserved and fun damental mammalian sex determining role. These investigations have provided many unique insights. Here, we review the recent molecular and endocrine i nvestigations into sexual development in marsupials, and highlight how thes e studies have shed light on the roles of genes and hormones in mammalian s ex determination and differentiation. J. Exp. Zool. 290:586-596, 2001. (C) 2001 Wiley-Liss, Inc.