Two Sperm Membrane Protein Gene Expression

In the contraception study, one. of the most attractive subjects is to use the specific antigen of sperm membrane as a contraceptive vaccine. As the limited sperm, it is difficult to isolate and purify the sperm membrane protein, and the gene engineering is to be thought the best way to resolve this problem. In the previous study, cDNA fragments encoding for rabbit sperm membrane protein and human sperm antigen were isolated from a rat testis λgtll cDNA expression vector library by epitope selection. In the current paper, we report exprimenls on the expression of the genes(RSD-l and RSD-2) in Chinese Hamster Ovary cells, and the determination of the stage of spernialogeiiesis when the genes are expressed by in situ hybridization.A mammalian expression vector(pSV₂,-EP) was reconstructed by inserting a oligonucleolide fragment into pSV₂dhfr plasmid. The characterastics of the expression vector are as follows: (1), contains SV₄₀ early promotor and origin of DNA replication; (2), contains SV₄₀ poty A site and splicing site; (3), contains a initiator ATG downstream the promotor, and the cloning site can be inserted with all cDNAs from Agtll library.Two recomhinant plasmids(pSVRS-1 and pSVRS-2) were constructed by inserting RSD-1 and RSD-2 into the EcoRI site of the expression vector pSV-EP. CHO dhfr' cells were co-transformed with pSV_tdhfr plasmid and pSVRS-1 and CHO cells were rotransformed with pSV_? plasmid and pSVRS-2 by calcium phosphate method. Under the selective pressure of no thymide and hypoxanthine medium or G448 selection,...