Fig. 2
Knockout of Nmi in the mammary epithelium alters mammary development. a Whole-mounted mammary glands from Nmi knockout mice and littermate controls. Ductal area in mm2 was measured by drawing a perpendicular line through the lymph node while excluding the area of the lymph node. Scale bar = 1000 μM; N = 5 control mice (Nmifl/fl) and 4 KO mice (Nmi−/−), *p < 0.05. b Mammary glands at lactation day 1 from Nmi KO and age matched control mice. Whole-mounted mammary glands and histological photomicrographs depict alveolar structures. Alveoli were quantified in H&E-stained sections and plotted as number of alveoli per section of mammary gland; Scale bar = 50 μM; N = 5 control mice (Nmifl/fl) and 4 KO mice (Nmi−/−), *p = 0.001. c Ki67 was used to quantify proliferating cells in alveoli. The percent of Ki67-positive cells per field of view is plotted; Scale bar = 5 μM; N = 5 control mice (Nmifl/fl) and 4 KO mice (Nmi−/−), *p = 0.0001. d Isolated mammary epithelial cells from mature nonparous mice were embedded in matrigel and stimulated with growth factors known to promote alveologenesis. Arrows indicate structures counted as individual branches on organoids. e Alveologenesis is plotted as average number of branches/structure. This experiment was repeated three times. *p < 0.05
