title: Apoptosis, onset and maintenance of spermatogenesis: evidence for the involvement of Kit in Kit-haplodeficient mice.
abstract: Kit/stem cell factor (SCF ) has been reported to be involved in survival and proliferation of male differentiating spermatogonial cells. This kinetics study was designed to assess the role of Kit/SCF during spermatogenesis in mice, and the extent of male programmed germ cell death was measured between 8 and 150 days of age. For this purpose, 129/Sv inbred mice in which one Kit allele was inactivated by an nlslacZ sequence insertion (Kit(W-lacZ/+)) were compared with 129/Sv inbred mice with wild-type alleles at the Kit locus. Four different approaches were used: 1) morphometric study to assess spermatogenesis, 2) flow cytometry to study testicular cell ploidy, 3) in situ end labeling to detect apoptosis, and 4) follow-up of reporter gene expression. Spermatogenesis was lower in Kit(W-lacZ/+) heterozygous mice both at the onset of spermatogenesis and during adulthood. Indeed, greater apoptosis occurred at the onset of spermatogenesis. This was followed in the adult by a smaller seminiferous tubule diameter and a lower ratio between type B spermatogonia and type A stem spermatogonia in Kit(W-lacZ/+) mice compared with Kit(+/+) mice. These differences are probably related to the Kit haplodeficiency, which was the only difference between the two genotypes. Germ cell counts and testicular cell ploidy revealed delayed meiosis in Kit(W-lacZ/+) mice. Reporter gene expression confirmed expression of the Kit gene at the spermatogonial stage and also revealed Kit expression during the late pachytene/diplotene transition. These results suggest involvement of Kit/SCF at different stages of spermatogenesis.
authors.affiliation: Physiopathologie de la Reproduction, Unité Mixte de Recherche 6073 "Physiologie de la Reproduction et des Comportements," Institut National de Recherche Agronomique, Centre National de la Recherche Scientifique, Université de Tours, Nouzilly, France.
authors.forename: Fabrice
authors.initials: F
authors.lastname: Guerif
authors.forename: Veronique
authors.initials: V
authors.lastname: Cadoret
authors.forename: Valerie
authors.initials: V
authors.lastname: Rahal-Perola
authors.forename: Jacques
authors.initials: J
authors.lastname: Lansac
authors.forename: Florence
authors.initials: F
authors.lastname: Bernex
authors.forename: Jean Jacques
authors.initials: JJ
authors.lastname: Panthier
authors.forename: Marie Thérèse
authors.initials: MT
authors.lastname: Hochereau-de Reviers
authors.forename: Dominique
authors.initials: D
authors.lastname: Royere
mesh_terms: D000483:Alleles; D000728:Androgens / Q000378:metabolism; D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D005260:Female; D005298:Fertility / Q000502:physiology; D005434:Flow Cytometry; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D006238:Haploidy; D020287:In Situ Nick-End Labeling; D007763:Lac Operon / Q000235:genetics; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D018345:Mice, Knockout; D011003:Ploidies; D011247:Pregnancy; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics* / Q000502:physiology*; D012671:Seminiferous Tubules / Q000378:metabolism / Q000502:physiology; D013091:Spermatogenesis / Q000502:physiology*; D013737:Testis / Q000502:physiology; D016707:Tissue Fixation; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D000728:Androgens; D019009:Proto-Oncogene Proteins c-kit; D001616:beta-Galactosidase