Abstract
BACKGROUND: The promyelocytic leukemia zinc finger gene Plzf (also called Zbtb16, Zfp145 or Green's luxoid) belongs to the POZ/zinc-finger family of transcription factors. It contains a BTB/POZ domain that mediates epigenetic transcriptional repression. PLZF is essential for proper skeleton patterning and male germ cell renewal. Two alleles have been reported that display similar phenotypes: a targeted knock-out, and the spontaneous nonsense mutation luxoid. RESULTS: We describe a new ENU induced missense allele of Plzf called seven toes (Plzf7t). Homozygous animals exhibit hindlimb and axial skeleton abnormalities. Whereas the skeletal abnormalities are similar to those of the other alleles, Plzf7t differs in that it does not cause spermatogonial depletion and infertility. Positional cloning revealed a point mutation changing the evolutionarily conserved amino acid Glu44 to Gly, possibly altering the BTB domain's activity. CONCLUSIONS: Plzf7t is a separation-of-function allele that reveals differential requirements for domains of PLZF in different developmental milieus.