MOLECULAR-CLONING AND CHARACTERIZATION OF EPI-1, THE MAJOR PROTEIN INCHIMPANZEE (PAN-TROGLODYTES) CAUDA EPIDIDYMAL FLUID

A 27-kDa glycoprotein comprises approximately 20% of the total protein in chimpanzee (Pan troglodytes) cauda epididymal fluid. Polyclonal an tibodies generated against this glycoprotein react with 27- and 25-kDa components in chimpanzee cauda epididymal fluid and in human, gorilla , chimpanzee, and monkey seminal fluid. According to microsequencing, the 27- and 25-kDa components (chimpanzee EPI-1) are identical to the cloned putative human epididymal protein HE1. Screening of a chimpanze e epididymal cDNA library enabled isolation of a cDNA clone of chimpan zee EPI-1. On the cDNA level, chimpanzee EPI-1 and hu man HE1 are 99% identical. Northern analysis localized chimpanzee EPI-1 mRNA to the di stal caput epididymidis. With EPI-1 primers, polymerase chain reaction of reverse-transcribed rhesus monkey (Macaca mulatta) epididymal RNA enabled isolation of a rhesus monkey EPI-1 cDNA clone. The derived ami no acid sequence of rhesus monkey EPI-1 is identical to chimpanzee EPI -1 and to human HE1. Northern analysis localized rhesus monkey EPI-1 m RNA to the distal caput and the proximal corpus epididymidis. Northern analysis also showed that chimpanzee EPI-1 and rhesus monkey EPI-1 ge ne products are expressed specifically in the epididymis and not in an y other tissue examined.