MOLECULAR-CLONING AND STRUCTURAL-ANALYSIS OF THE GENE ENCODING PERF-15 PROTEIN PRESENT IN THE PERINUCLEAR THECA OF THE RAT SPERMATOZOA

We have cloned the PERF 15 gene, which encodes the most abundant prote in of the perinuclear theca of rat spermatozoa. PERF 15 is related to the superfamily of lipophilic transport proteins. It has a molecular w eight of 15 060 and is present exclusively in the subacrosomal region of the sperm head. Northern blot analysis demonstrated that this gene transcribed PERF 15 mRNA in meiotic and postmeiotic cells. The PERF 15 gene contains four exons and three introns. Exon 1 codes for amino ac ids 1-24, exon 2 for amino acids 25-82, exon 3 for amino acids 83-116, and exon 4 for amino acids 117-132. The three introns are composed of 2241, 547, and 164 base pairs (bp), respectively. The exon/intron bou ndaries are identical to those found in the mouse myelin P2 gene, but there is no resemblance in size and sequence between the corresponding introns of the PERF 15 and myelin P2 genes. Localization of the initi ation transcription site by primer extension showed that the 5'-untran slated region of this gene is 67 bp upstream of the translation initia tion site. Primer extension analysis also suggests that there is one t ranscription start site for this gene. Inverse polymerase chain reacti on generated a 204-bp fragment, located upstream of the translation in itiation codon, that has some homology with regions of other mammalian genes.