title: Colony stimulating factor 1 is required for mammary gland development during pregnancy.
abstract: The study of colony stimulating factor 1 (CSF-1), a homodimeric serum growth factor that regulates mononuclear phagocytes and is involved in maternal-fetal interactions during pregnancy, was dramatically enhanced by the observation that the recessive mutation osteopetrosis, op, is an inactivating mutation in the CSF-1-encoding gene. Homozygous mutant (op/op) mice completely lack CSF-1, are osteopetrotic consequent to a deficiency in osteoclasts, have severely reduced numbers of macrophages, and have reduced fertility evident at the pre- and postimplantation stages of pregnancy. We show here that op/op females have a lactational defect, and consequently, although some are able to produce offspring, few nurture any pups and none feeds a full litter. This lactational defect is due to incomplete mammary gland ductal growth during pregnancy, a precocious development of the lobulo-alveolar system, and despite expression of milk proteins, a failure to switch to a lactational state. These data show that CSF-1 has a role in the development of the mammary gland during pregnancy.
authors.affiliation: Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461.
authors.forename: J W
authors.initials: JW
authors.lastname: Pollard
authors.forename: L
authors.initials: L
authors.lastname: Hennighausen
mesh_terms: D000818:Animals; D015152:Blotting, Northern; D003433:Crosses, Genetic; D005260:Female; D015870:Gene Expression; D005838:Genotype; D016173:Macrophage Colony-Stimulating Factor / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D008297:Male; D008321:Mammary Glands, Animal / Q000166:cytology / Q000473:pathology / Q000502:physiology*; D051379:Mice; D008817:Mice, Mutant Strains; D010022:Osteopetrosis / Q000235:genetics* / Q000473:pathology; D011247:Pregnancy; D011248:Pregnancy Complications / Q000473:pathology / Q000503:physiopathology*; D011270:Pregnancy, Animal / Q000502:physiology*; D012333:RNA, Messenger / Q000032:analysis
chemical_list: D012333:RNA, Messenger; D016173:Macrophage Colony-Stimulating Factor