Sperizin is a murine RING zinc-finger protein specifically expressed in haploid germ cells

Through the preparation of a subtracted cDNA library, we have extensively i solated genes whose expression is induced in mouse spermatogenic cells. One of the genes encoded a protein with a RING zinc-finger motif, which we ter med sperizin (spermatid-specific ring zinc finger). Transcription of the sp erizin gene was not observed in prepubertal testis, but became detectable a t day 23. Northern and in situ hybridization analyses indicated that the sp erizin gene was exclusively expressed in the round spermatid. The sperizin gene is intronless, and GFP-tagged sperizin was found to be localized in th e cytoplasm of ectopically expressed somatic cultured cells. We assigned th e chromosomal localization of the sperizin gene to chromosome 17 using an i nterspecific backcross mapping panel. The data suggest that we have identif ied a new member of the RING-finger family of proteins that may be involved in spermatogenesis. (C) 1999 Academic Press.