Isolation and sequencing of doublesex/male abnormal 3 (DM) related transcription factor (Dmrt) genes from the Asian toad Bufo gargarizans (Cantor, 1842)

The doublesex/male abnormal 3 (dsx/mab-3 or DM) domain gene family involved in sexual development encodes putative transcription factors including a DNA-binding homology motif, the DM domain. We used highly degenerate primers to clone and sequence seven distinct DM related transcription factor (Dmrt) genes from the Asian toad (Bufo gargarizans Cantor, 1842). A database search for the cloned sequences revealed the following percentage identity with the homologous Dmrt genes of the human: BgDmrt1 = 97 percent, BgDmrt2 = 97 percent, three isoforms of BgDmrt3 (BgDmrt3a = 93 percent, BgDmrt3b = 95 percent, BgDmrt3c = 100 percent) and two isoforms of BgDmrt5 (BgDmrt5 = 97 percent, BgDmrt5 = 91 percent). Based on DM domain amino acid sequence similarities we constructed a phylogenetic tree which grouped vertebrate and invertebrate Dmrt genes into seven distinct subfamilies. The DM domains of both human and the newly-discovered Bufo gargarizans genes contained two conserved zinc-chelating sites (CCHC and HCCC), except BgDmrt3b, which contained the CCRC and HCCC sites.

Isolation and sequencing of seven Sox genes from the lacertid lizard Eremias breuchleyi

The Sox family of genes shares a high sequence similarity with the HMG box region of the human Y chromosomal gene, SRY. We used highly degenerate primers to clone and sequence seven Eremias breuchleyi Sox genes (EbSox2, EbSox3, EbSox4, EbSox11, EbSox12, EbSox14 and EbSox21). A database search for the cloned sequences revealed the following percentage identity with the homologous human SOX genes: EbSox2 = 96 percent, EbSox3 = 88 percent, EbSox4 = 94 percent, EbSox11 = 99 percent, EbSox12 = 96 percent, EbSox14 = 98 percent, EbSox21 = 97 percent. Cluster analysis indicates that they seem to belong to group B and group C of Sox gene family, respectively.