Fig. 1. Stat6 is upregulated and activated at the onset of pregnancy. (A) Protein was extracted from inguinal mammary glands from virgin mice; from mice at day 5, 10 and 15 of gestation; and from mice at day 0 (day of birth), 5 and 10 of lactation. Immunoblotting was performed for phosphorylated Stat6 (pStat6), Stat6, IL-4R, Gata3, c-Maf and -tubulin. pStat6 and Stat6 immunoblots were quantified using ImageJ software and plotted on a histogram (right). (B-I) Immunohistochemistry (IHC, right panels; left panels, merged with DAPI staining) was performed on mammary gland sections from wild-type mice for: pStat6 in virgin mice (B) and mice at day 5 of gestation (C); IL-4R in virgin mice (D) and mice at day 15 of gestation (E); Gata3 in mice at day 5 of gestation (F); and c-Maf in mice at day 15 of gestation (G). (H) pStat6 staining in Stat6^-/- mice at day 5 of gestation. (I) Rabbit isotype control staining on wild-type mice at day 5 of gestation.