MULTIPLE FORMS OF MESSENGER-RIBONUCLEIC-ACID ENCODING GLYCODELIN IN MALE GENITAL-TRACT

Glycodelin-A is a human endometrium-derived glycoprotein with contrace ptive and immunosuppressive activities. Recently, we found that semina l plasma contains immunoreactive glycodelin (GdS) that is differential ly glycosylated and has no contraceptive activity. We now report local ization and Variant forms of GdS in the male genital tract. Northern b lot and reverse transcription-PCR analyses showed that GdS mRNA is exp ressed in the seminal vesicles and ampulla of the vas deferens. Immuno histochemical staining localized GdS to the epithelial cells and lumen of glands in the seminal vesicles and ampullary part of the vas defer ens. The same tissues and cells contained glycodelin mRNA as localized by in situ hybridization. Whereas the major reverse transcription-PCR products were identical to the glycodelin-A cDNA from decidual expres sion library, there were also several splicing variants of GdS mRNA. S eminal plasma also contained smaller immunoreactive forms of the GdS p rotein. Some of them were posttranslational cleavage products of GdS, because incubation of I-125-labeled GdS in seminal plasma resulted in smaller molecular weight cleavage products. Based on these results, we concluded that multiple forms of glycodelin mRNA are expressed in the male genital tract, including those lacking the coding sequences for the glycosylation sites, and that seminal plasma has proteolytic activ ity that cleaves GdS.