Putative Homeodomain Transcription Factor 2 (PHTF2)

The conservation between mouse and human proteins extends over the entire protein and is localized at the putative homeodomain and at the N- and C-terminal regions of Drosophila protein sequence. Blast searches allowed us to identify another member of the PHTF family, PHTF2, located at 7q11.23-q21 of the human genome. The human and mouse genes display 98% similarity to one another, 56% similarity with the Drosophila gene, and 67% similarity with PHTF2, suggesting that phtf might define a novel gene family of highly divergent homeobox genes. Finally, Northern blot analysis showed that while PHTF1 is expressed mainly in testis, PHTF2 is predominantly expressed in muscle, suggesting that these two genes may have acquired different functions after their duplication and divergence.