The early history of the Sox genes.

The Sox gene family was discovered in 1990 through the cloning of Sry, the mammalian Y-linked testis-determining gene. This was long before genome sequencing was routine, but it was an exciting time when rapid progress was being made in gene discovery, through positional and functional cloning techniques, and via homology within and between species. It had become clear that many genes were members of often quite substantial families, related by the possession of similar domains within their coding sequences and corresponding proteins. Members of the SOX protein family were subsequently shown to have many diverse roles during development in metazoan species, but are all related by a similar HMG box type of DNA binding domain, which gives them functional properties distinct from other transcription factors. This is a brief account of how the first Sox genes were found.