An orthologue of Dmrt1 has been cloned and characterized in the lizard, Calotes versicolor (CvDmrt1). CvDmrt1 encodes alternatively spliced transcripts in genital ridge during gonadal differentiation and in adult testis. Its expression in genital ridge initiates from day 3 and is restricted to mesenchymal cells, which differentiate into the Sertoli cells. Lack of expression in the coelomic epithelium of GR shows that CvDmrt1 expression occurs only in the testicular pathway, and that the Sertoli and granulosa cells in GR may originate from different primordia. From day 25 onwards, the expression shifts majorly towards the germ cells both in testis and ovary. Thus its role in sexual differentiation of C. versicolor, which lacks CSD and TSD, is well documented.