Fig. 2

p40 treatment increases growth and epithelial cell proliferation before weaning in wild-type mice. Mice were treated with p40-containing hydrogels at 0.5, 1, and 1.5 μg/day at postnatal days 2–6, 7–13, and 14–21, respectively. As control, pups were treated with hydrogels without p40 (no-p40). a Bodyweight was recorded. The fold change of bodyweight was calculated by comparing the bodyweight at the indicated postnatal day to the bodyweight at birth of the same pup. b The percentage of increase = (p40 bodyweight−average of no-p40 bodyweight)/average of no-p40 bodyweight, at the matched postnatal day. c Real-time PCR analysis was performed to detect Ki67 gene expression in the small intestine and the colon. The average of mRNA expression levels in 2- and 3-week-old mice in the no-p40 group were set as 100%, and the mRNA expression level of each mouse was compared to the average at the same age. d, e Ileal and colonic tissues from 2-week-old mice were immunostained using an anti-Ki67 antibody and a horseradish peroxidase-conjugated secondary antibody. Slides were developed using DAB and counterstained with hematoxylin. The numbers of positively stained cells are shown. f–g Ileal tissues from 2-week-old mice were prepared for H&E staining and the number of villi per mm is shown. In a, b, no-p40 group: n = 15; p40 group: n = 17. In c, g n = 5–7 in each group