Fig. 3: Ablation of Mettl3 causes infertility due to compromised uterine receptivity and decidualization.

Representative immunofluorescence images (A) and the percentage (B) of Ki67+ epithelial cells and stromal cells in uterine of Mettl3 cKO and control mice on GD4. Data were calculated using 11 images from 3 control mice and 14 images from 3 Mettl3 cKO mice. Representative immunofluorescence images (C) and quantification of E-cadherin (D) in uterine epithelial cells of Mettl3 cKO and control mice on GD4. Fluorescence intensities of uterine epithelial E-cadherin were calculated using 6 images from 3 control mice and 12 images from 3 Mettl3 cKO mice. Representative immunofluorescence images (E) and the percentage (F) of Ki67+ epithelial cells and stromal cells in uterine of Mettl3 cKO and control mice following induction of artificial pregnancy (pollard experiment). Data were calculated using 12 images from 3 control mice and 7 images from 3 Mettl3 cKO mice. Representative immunofluorescence images (G) and quantification of E-cadherin (H) in uterine epithelial cells of Mettl3 cKO and control mice following induction of artificial pregnancy. Fluorescence intensities of uterine epithelial E-cadherin were calculated using 12 images from 3 control mice and 15 images from 3 Mettl3 cKO mice. A, C, E, G Nuclei were stained with DAPI. Scale bars: 75 μm. I Immunohistochemistry of METTL3 with paraffin sections from pregnant females on GD0 and GD5. Sections are counterstained with hematoxylin. Brown staining denotes METTL3+ cells. Scale bars: 100 μm. J Representative pictures showing the gross morphology of oil-treated uterine horns (left horn) and untreated uterine horns (right horn) from control (n = 6) and Mettl3 cKO mice (n = 6) collected 5 days after oil injection. Scale bars: 1 cm. K The weight per unit length of oil-injected and untreated uterine horns in (J). Data are presented as mean ± SD, **P < 0.01. L Histology of control and Mettl3 cKO mice uterus in (J), as measured by HE staining, Scale bars 200 μm. M Relative mRNA levels of decidualization marker genes (Wnt4, Bmp8a, Bmp2, Prl8a2) in the uterine horns of control and Mettl3 cKO mice in (J). B, D, F, H, M Data are presented as mean ± SD, *P < 0.05, **P < 0.01, ***P < 0.001, relative to control and unstimulated.