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 protein of the perinuclear theca of rat spermatozoa. PERF 15 is related to the superfamily of lipophilic transport proteins. It has a molecular weight 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 acids 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 boundaries 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 initiation transcription site by primer extension showed that the 5'-untranslated region of this gene is 67 bp upstream of the translation initiation site. Primer extension analysis also suggests that there is one transcription start site for this gene. Inverse polymerase chain reaction generated a 204-bp fragment, located upstream of the translation initiation codon, that has some homology with regions of other mammalian genes.