DAX1 origin, function, and novel role.

The orphan nuclear receptor NR0B1 encodes the DAX1 protein, which stands for the dosage sensitive sex-reversal (DSS), adrenal hypoplasia congenita (AHC) critical region on the X-chromosome, gene 1. DAX1 was initially identified as part of a contiguous gene syndrome and is known to function in the proper formation of the adult adrenal gland. It has been hypothesized that DAX1 is responsible for the establishment and maintenance of the steroidogenic axis of development. Recent insight from the murine ortholog Dax1 along with reports of an alternatively spliced variant in humans suggests that Dax1 has additional functional roles beyond those previously understood. Here, we review DAX1/Dax1 known functional roles and the recently hypothesized function in the development of the embryo and in the maintenance of embryonic stem cell pluripotency.