title: Expression of c-Kit receptor mRNA and protein in the developing, adult and irradiated rodent testis.
abstract: Germ cell proliferation, migration and survival during all stages of spermatogenesis are affected by stem cell factor signalling through the c-Kit receptor, the expression and function of which are vital for normal male reproductive function. The present study comprehensively describes the c-Kit mRNA and protein cellular expression profiles in germ cells of the postnatal and adult rodent testis, revealing their significant elevation in synthesis at the onset of spermatogenesis. Real-time PCR analysis for both mice and rats matched the cellular mRNA expression profile where examined. Localization studies in normal mouse testes indicated that both c-Kit mRNA and protein are first detectable in differentiating spermatogonia. In addition, all spermatogonia isolated from 8-day-old mice displayed detectable c-Kit mRNA, but 30-50% of these lacked protein expression. The c-Kit mRNA and protein profile in normal rat testes indicated expression in gonocytes, in addition to differentiating spermatogonia. However, in the irradiated adult rat testes, in which undifferentiated spermatogonia are the only germ cell type, mRNA was also detected in the absence of protein. This persisted at 3 days and 1 and 2 weeks following treatment with gonadotrophin-releasing hormone (GnRH) antagonist to stimulate spermatogenesis recovery. By 4 weeks of GnRH antagonist treatment, accompanying the emergence of differentiating spermatogonia, both mRNA and protein were detected. Based on these observations, we propose that c-Kit mRNA and protein synthesis are regulated separately, possibly by influences linked to testis maturation and circulating hormone levels.
authors.affiliation: Centre for Reproduction and Development, Monash Institute of Medical Research, Monash University, Clayton, Victoria 3168, Australia.
authors.forename: Sridurga Mithra
authors.initials: SM
authors.lastname: Prabhu
authors.forename: Marvin L
authors.initials: ML
authors.lastname: Meistrich
authors.forename: Eileen A
authors.initials: EA
authors.lastname: McLaughlin
authors.forename: Shaun D
authors.initials: SD
authors.lastname: Roman
authors.forename: Sam
authors.initials: S
authors.lastname: Warne
authors.forename: Sirisha
authors.initials: S
authors.lastname: Mendis
authors.forename: Catherine
authors.initials: C
authors.lastname: Itman
authors.forename: Kate Lakoski
authors.initials: KL
authors.lastname: Loveland
mesh_terms: D000818:Animals; D007150:Immunohistochemistry / Q000379:methods; D017403:In Situ Hybridization / Q000379:methods; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008815:Mice, Inbred Strains; D019009:Proto-Oncogene Proteins c-kit / Q000032:analysis / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013093:Spermatogonia / Q000737:chemistry; D013737:Testis / Q000737:chemistry* / Q000254:growth & development / Q000528:radiation effects
chemical_list: D012333:RNA, Messenger; D019009:Proto-Oncogene Proteins c-kit