{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,5]],"date-time":"2026-10-05T15:35:50Z","timestamp":1791214550367,"version":"4.1.0"},"reference-count":0,"publisher":"National Academy of Sciences","issue":"20","content-domain":{"domain":["www.pnas.org"],"crossmark-restriction":true},"short-container-title":["Proc. Natl. Acad. Sci. U.S.A."],"published-print":{"date-parts":[[1994,9,27]]},"abstract":"<jats:p>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.<\/jats:p>","DOI":"10.1073\/pnas.91.20.9312","type":"journal-article","created":{"date-parts":[[2006,5,31]],"date-time":"2006-05-31T08:56:09Z","timestamp":1149065769000},"page":"9312-9316","update-policy":"https:\/\/doi.org\/10.1073\/pnas.cm10313","source":"Crossref","is-referenced-by-count":152,"title":["Colony stimulating factor 1 is required for mammary gland development during pregnancy."],"prefix":"10.1073","volume":"91","author":[{"given":"J W","family":"Pollard","sequence":"first","affiliation":[{"name":"Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"L","family":"Hennighausen","sequence":"additional","affiliation":[{"name":"Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, NY 10461."}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"341","published-online":{"date-parts":[[1994,9,27]]},"container-title":["Proceedings of the National Academy of Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pnas.org\/doi\/pdf\/10.1073\/pnas.91.20.9312","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,4,13]],"date-time":"2022-04-13T14:02:33Z","timestamp":1649858553000},"score":1,"resource":{"primary":{"URL":"https:\/\/pnas.org\/doi\/full\/10.1073\/pnas.91.20.9312"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1994,9,27]]},"references-count":0,"journal-issue":{"issue":"20","published-print":{"date-parts":[[1994,9,27]]}},"alternative-id":["10.1073\/pnas.91.20.9312"],"URL":"https:\/\/doi.org\/10.1073\/pnas.91.20.9312","relation":{},"ISSN":["0027-8424","1091-6490"],"issn-type":[{"value":"0027-8424","type":"print"},{"value":"1091-6490","type":"electronic"}],"subject":[],"published":{"date-parts":[[1994,9,27]]},"assertion":[{"value":"1994-09-27","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}