Stage-specific detection of mRNA for the sperm antigen SP-10 in human testes.
SP-10 is a sperm-specific, intra-acrosomal protein that is considered to be a vaccine candidate for immunocontraception. In the present study, in situ hybridization with biotin and 35S labeled riboprobes was used to determine the pattern of SP-10 mRNA expression in human testes. Both methods demonstrated SP-10 mRNA primarily in round spermatids found in stages I, II, and III of the seminiferous cycle. Morphometric analysis of silver grains with the 35S-labeled probe showed less SP-10 mRNA in spermatids at stages IV, V, and VI than in previous stages, and rarely was label found in spermatogonia or spermatocytes. The expression of SP-10 mRNA first appeared at stage I coincident with the appearance of the protein, which was shown previously to persist in the acrosomal matrix throughout spermiogenesis. The decrease in SP-10 mRNA occurred when spermatids underwent polarization, nuclear condensation, and elongation. The appearance of SP-10 mRNA in round spermatids suggests that increases in SP-10 transcription or SP-10 mRNA stability or both occur as spermatids develop from the Golgi phase to the cap phase. The subsequent decline of SP-10 mRNA, despite the persistence of the SP-10 protein in all spermatids, suggests that a decrease in SP-10 transcription or an increase in mRNA degradation occurs when spermatids elongate.
Department of Anatomy and Cell Biology, University of Virginia, Charlottesville 22908.
B E
BE
Kurth
R M
RM
Wright
C J
CJ
Flickinger
J C
JC
Herr
D000177:Acrosome / Q000276:immunology; D000941:Antigens / Q000235:genetics*; D012739:Gonadal Steroid Hormones / Q000235:genetics*; D006801:Humans; D017403:In Situ Hybridization; D008297:Male; D008565:Membrane Proteins; D009693:Nucleic Acid Hybridization; D012333:RNA, Messenger / Q000032:analysis*; D013087:Spermatids / Q000254:growth & development / Q000276:immunology*; D013091:Spermatogenesis / Q000276:immunology*
C512729:ACRV1 protein, human; D000941:Antigens; D012739:Gonadal Steroid Hormones; D008565:Membrane Proteins; D012333:RNA, Messenger