POSTMEIOTIC EXPRESSION OF THE MOUSE DIHYDROPYRIMIDINASE-RELATED PROTEIN-3 (DRP-3) GENE DURING SPERMIOGENESIS

The dihydropyrimidinase-related protein (DRP) family, originally ident ified in humans by their homology to dihydropyrimidinase, contains at least four members. Genes of this family, and their counterparts in ot her mammals and chickens, are expressed mainly in fetal and neonatal b rain, suggesting that the encoded proteins have a physiological role i n the development of the central nervous system. In addition, the DRP- 3 gene is expressed in testis as a shorter mRNA than the brain form. A s a first step in understanding the extra-neuronal function of DRP-3, the structure and expression of testis DRP3 were examined. Testis DRP- 3 cDNA showed the same sequence as brain DRP-3 cDNA, except for the 5' -terminal end, which encodes a 5'-untranslated region and the 11 N-ter minal amino acid residues, indicating that the two forms of DRP3 mRNA were transcribed from a single copy gene. Northern blotting analysis d etected DRP3 mRNA in 30-, 40- and 70-day-old, but not in 10- and 20-da y-old testes. In situ hybridization analysis indicated that the expres sion of DRP-3 in testis is restricted to post-meiotic round spermatids . This is the first report of the expression of DRP genes in extra-neu ronal cells. Mol. Reprod. Dev. 51:105-111, 1998. (C) 1998 Wiley-Liss, Inc.