Specific Sperm Membrane Proteins Hsmp-1 Gene Structure

It is supposed that anti-sperm antibody may be one of the cause of unexplained infertility. In our previous study, we have examined anti-sperm antibodies from sera of 300 infertile patients and 204 normal subjects by immunoblot analysis. Sera with high titer of anti-sperm protein hSMP-1 from infertile patient was used for epitope screening from human testis λ gt11 expression cDNA library. An insert fragment of 1.7kb was separated and designated as HSD-1, its open reading frame of HSD-1 was not complete and the 3' untranslated region was truncated.The transcriptional vector pGEM-2Z was recombined with HSD-1 , and the transcriptional level in testis was studied by in situ hybridization. It shows that hSMP-1 gene might be expressed at transcriptional level in different stages of spermatogenesis including spermatogonia, spermatocytes and spermatid of seminiferous epithelium. High level expression of HSD-1 in Escherichia coli under the control of the T7 promoter was obtained. Immunofluorescence data showed that hSMP-1 was localized to the head of human sperm with a cap-shaped pattern, which was similar in morphology to the human sperm acrosome.To complete the full length nucleotide sequence, 1.7kb fragment and 800bp from 5' end of HSD-1 were used as probes to rescreen the human testis λ gt11 expression cDNA library and the human testis x gt10 5' stretch cDNA library. 10 positive clones have been obtained. The completed cDNA of hSMP-1 was identified and sequenced . After sequencing and analyzing the 5 of the above 10 positive cDNA clones, some heterologies were found when compared with HSD-1 sequence. The heterologies include 5' end alternation, deletion, insertion and so on. It is suggested that the cDNA coding for hSMP-1 is a complicated...