Expression of a Gene Encoding a Specific Human Sperm Protein in Chinese Hamster Ovarian Cells

The cDNA (RSD-2) encoding a human sperm protein (YWK-II) was isolated from a rat testis Λgtl 1 expression library. Its nucleotide sequence was determined. The deduced polypeptide showed high identity with the transmembrane-cytoplasmic domains of A4 amyloid precursor protein of Alzheimer's disease. The RSD-2 was inserted into the EcoRI site of the pSV2 -EP vector to construct the pSVRS-2 vector. Chinese hamster ovarian (CHO-dhfr) cells were cotransformed with pSV2 -neo and pSVRS-2. mRNA and chromosomal DNA prepared from the transformed cells interacted with [32P]RSD-2 as probe by dot hybridization. The production of the YWK-II protein was determined by staining with the YWK-II mAb by an indirect immunofluorescence technique. There was marked staining of the cytoplasm. The RSD-2 cDNA encoding the YWK-II sperm was expressed in the transformed CHO cells. The pSV2 -EP vector and the CHO cell expression system can be utilized to produce sperm proteins for antifertility studies.