title: Mice lacking cyclin D1 are small and show defects in eye and mammary gland development.
abstract: Using homologous recombination, mice lacking cyclin D1 were generated by replacing most of the first exon of the Cyl-1 gene with sequences encoding neomycin resistance. Cyl-1(-1-) mice were viable and fertile but consistently smaller than their heterozygous or wild-type littermates. The nullizygous animals also showed two distinctive abnormalities: a severe retinopathy caused by impaired development of all layers of the retina and, in the mammary gland during pregnancy, a marked reduction in acinar development accompanied by a failure to lactate. Approximately 50% of animals also had a malformation of the jaw that manifested itself as a misalignment of the incisor teeth. Mouse embryo fibroblasts isolated from 14 day nullizygous, heterozygous, or wild-type embryos and grown under standard conditions showed similar cell-cycle and growth characteristics. Thus although cyclin D1 kinase activity may facilitate G1 progression, it is not essential for the development of most tissues and organs, and only a few specialized cell lineages are demonstrably sensitive to its absence.
authors.affiliation: Laboratory of Viral Carcinogenesis, Imperial Cancer Research Fund (ICRF), London, UK.
authors.forename: V
authors.initials: V
authors.lastname: Fantl
authors.forename: G
authors.initials: G
authors.lastname: Stamp
authors.forename: A
authors.initials: A
authors.lastname: Andrews
authors.forename: I
authors.initials: I
authors.lastname: Rosewell
authors.forename: C
authors.initials: C
authors.lastname: Dickson
mesh_terms: D000818:Animals; D001483:Base Sequence; D001824:Body Constitution / Q000235:genetics*; D002453:Cell Cycle; D002454:Cell Differentiation; D002478:Cells, Cultured; D019938:Cyclin D1; D016213:Cyclins / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D017931:DNA Primers; D005260:Female; D005347:Fibroblasts / Q000378:metabolism; D015870:Gene Expression; D018390:Gene Targeting; D006579:Heterozygote; D006720:Homozygote; D007569:Jaw Abnormalities / Q000235:genetics; D008321:Mammary Glands, Animal / Q000002:abnormalities*; D051379:Mice; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D015513:Oncogene Proteins / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D011247:Pregnancy; D011995:Recombination, Genetic / Q000235:genetics; D012160:Retina / Q000002:abnormalities*; D013234:Stem Cells / Q000378:metabolism
chemical_list: D016213:Cyclins; D017931:DNA Primers; D015513:Oncogene Proteins; D019938:Cyclin D1