The PTX family of homeodomain transcription factors during pituitary developments.

A subfamily of bicoid-related homeodomain factors was recently discovered through its involvement in transcription of pituitary-specific genes. We isolated the first member of this family, Ptxl (pituitary homeobox 1), through its DNA binding properties whereas a second related gene, Ptx2 (RIEG), was identified by positional cloning as the causative gene for Rieger's syndrome. The mechanisms of Ptx action on its target genes as well as its putative roles during development are reviewed with particular emphasis on its role in pituitary function.