Fig. 1: Conditional deletion of SMAD1/5 results in female infertility.

a–h pSMAD1/5 immunohistochemistry (IHC) at 1.5 dpc a–b, 2.5 dpc c–d, 3.5 dpc e–f, and 4.5 dpc (black dotted lines indicate primary decidual zone) g–h. E, embryo. Representative image of the embryo, observed in at least three specimens from different mice. Images in a–h represent findings observed in at least three individual samples per pregnancy timepoint. i–n pSMAD1/5 IHC in human endometrial biopsies obtained during the proliferative phase I, k or mid-secretory j, l of the menstrual cycle. m, n are negative controls, yellow arrows in j, l point to positive decidualized cells in the mid-secretory phase endometrium. Images shown are representative of patterns observed in three proliferative phase and six mid-secretory phase individuals. o–v H&E-stained uterine cross-sections from 12-week-old control o–p, Smad1 cKO q–r, Smad5 cKO s–t, and Smad1/5 cKO u–v mice. w–x Fertility assessment in Control (n = 8), Smad1 cKO (n = 8), Smad5 cKO (n = 8), and Smad1/5 cKO (n = 8) mice over the course of 6 months. Total pups per month are plotted in w, whereas the number of pups per female per month is plotted in x. Plotted as average pups per female per month ± standard error of the mean (SEM), n = 8 per genotype.