Octamer Binding Transcription Factor 6 (OCT6)

The location of POU3F1 was consistent with this position, mapping to 1p34.1 by FISH. Contrary to the prediction, however, POU3F3 was mapped to 3p14.2 by the same method. The human POU3F2 and POU3F4 genes map to 6q16 and Xq21.1, respectively. Thus, the 4 human class III POU genes map to different chromosomes. A phylogenetic tree of these 4 genes shows that they emerged in a common ancestor of vertebrates. Studies of the genome structure of vertebrates suggest that genome duplication occurred at least twice in the early stage of vertebrate evolution; 4 homologous complexes such as Hox and MHC are interspersed in the mammalian genome. The findings with the 4 class III POU genes are consistent with the idea of 2 genome duplications.