A mouse zinc finger gene which is transiently expressed during spermatogenesis

Zinc finger proteins are polypeptides with sequence-specific, nucleic acid-binding properties. Substantial evidence has established them as a class of trans-acting molecules with regulatory roles in cellular growth and differentiation. We have screened an 11.5 day post coitum urogenital ridge cDNA library with an oligonucleotide encoding a sequence conserved between a variety of zinc finger proteins. By cDNA cloning and sequencing we show that a novel mouse gene, Zfp-35, encodes a protein with a block of 18 zinc finger domains and an N-terminal region rich in acidic residues. The 2.4 kb mRNA encoding this polypeptide is selectively expressed in adult testis, by comparison with other organs. We have analysed Zfp-35 expression in whole testes of sex-reversed mice, whole testes of prepuberal XY animals, germ cell fractions from XY adult testes and by in situ hybridization to sections from adult XY testes. Our studies show that a considerable increase in expression is restricted to spermatocytes at the pachytene stage of meiotic prophase. These experiments suggest that Zfp-35 may act to control gene activity during this particular stage of spermatogenesis.