title: A 43 kD c-mos protein is only expressed before meiosis during rat spermatogenesis.
abstract: We have investigated the RNA and protein expression pattern of the rat c-mos proto-oncogene during spermatogenesis. In mouse testis a 43kD c-mos protein is expressed throughout spermatogenesis, which is in agreement with one report detecting a 1.7 kb c-mos RNA in pachytene spermatocytes and in early spermatids. However, several other reports show that the mouse 1.7 kb c-mos RNA is exclusively expressed in post-meiotic male germ cells. We report that in rat male germ cells three c-mos RNA species of 5, 3.6 and 1.7 kb are detectable by Northern blotting analysis both before and after meiosis, with highest levels in early spermatids. However, western immuno-blot analysis reveals the presence of a 43 kD c-mos protein in total testis and pachytene spermatocytes, but not in post-meiotic cells. These findings combined with those made in the mouse system strongly suggest that c-mos protein may be a regulator of meiosis during spermatogenesis.
authors.affiliation: Department of Medical Biochemistry, University of Calgary, Alberta, Canada.
authors.forename: F A
authors.initials: FA
authors.lastname: van der Hoorn
authors.forename: J E
authors.initials: JE
authors.lastname: Spiegel
authors.forename: M F
authors.initials: MF
authors.lastname: Maylié-Pfenninger
authors.forename: S K
authors.initials: SK
authors.lastname: Nordeen
mesh_terms: D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D015870:Gene Expression / Q000502:physiology*; D008297:Male; D008540:Meiosis / Q000502:physiology*; D011518:Proto-Oncogene Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D017231:Proto-Oncogene Proteins c-mos; D012313:RNA / Q000235:genetics / Q000378:metabolism; D051381:Rats; D013087:Spermatids / Q000378:metabolism / Q000502:physiology; D013091:Spermatogenesis / Q000502:physiology*; D013094:Spermatozoa / Q000378:metabolism / Q000502:physiology; D013737:Testis / Q000378:metabolism / Q000502:physiology
chemical_list: D011518:Proto-Oncogene Proteins; D012313:RNA; D017231:Proto-Oncogene Proteins c-mos