Aard is specifically up-regulated in Sertoli cells during mouse testis differentiation.

Aard (alanine and arginine rich domain) is a gene of unknown function, previously reported to show sexually dimorphic expression in fetal mouse gonads. Here we describe the spatio-temporal expression profile of Aard during gonad development. The period of elevated mRNA expression coincides with early differentiation of the testis and is limited to Sertoli cells of the developing testis cords. Although low levels of Aard transcripts were detected in other tissues by quantitative RT-PCR assays, high levels of Aard expression is specific to the testis in both embryonic and adult mice.