title: Mice: progesterone and the regulation of strain differences in pregnancy-induced nest building.
abstract: Pregnant DBA/2J females built significantly larger and more completely enclosed nests than did pregnant C57BL/6J mice. This strain difference was restricted to the last half of gestation and was not observed during either the virgin state or lactation. Genotype-based differences in pregnancy-induced nest building were not related to circulating levels of progesterone (P), core temperature, or body weight. Exposure to supplemented P during pregnancy elevated nest building exhibited by pregnant C57BL females but did not induce DBA-like levels of the behavior. Also, virgin DBA females built larger nests in response to P than did C57BL females. These findings suggest that differences in the sensitivity of central neural tissue to steroid hormones may account for genotypically determined variation in patterns of pregnancy-induced nest building.
mesh_terms: D000818:Animals; D001831:Body Temperature; D001835:Body Weight; D005260:Female; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D009425:Nesting Behavior / Q000502:physiology*; D011247:Pregnancy; D011374:Progesterone / Q000097:blood*; D013045:Species Specificity
chemical_list: D011374:Progesterone