Fig. 1: DNMT1-mediated 5mC maintenance is indispensable for choriogenesis and fertilization.

a, a’ Spatial 5mC modification was detected in six different tissues, and temporal 5mC levels in ovaries during the first reproductive period were analyzed by dot blotting using a 5mC-specific antibody. The same amounts of gDNA were loaded as input in each panel. b Gene expression patterns of Dnmt1 in the ovaries during the first reproductive period were detected by qRT-PCR, n = 3 biologically independent samples. c 5mC levels were detected after RNAi of Dnmt1 by dot blotting, and the density for each sample was calculated, n = 4 biologically independent samples. d LC–MS/MS detection for the 5mC levels under dsRNA treatment, n = 3 biologically independent samples. e Calculation of hatching rates under RNAi of Dnmt1 and negative control. The atrophied and wizened phenotypes of oothecae in dsDnmt1 group compared with dsCK control group were showed, n = 3 biologically independent experiments. f DAPI staining was used to observe the development of embryos or unfertilized eggs, 36 h, 60 h, and 84 h post ootheca-laying were selected. The arrows point to the position of embryogenesis. More than three eggs were observed in each treatment group. g Pronucleus staining for the eggs using α-tubulin antibody. More than five eggs were observed in each treatment group. h SEM observation of sponge-like bodies on eggs, 9 of 13 sponge-like bodies were observed abnormal. i DAPI and PHA staining for nuclei and actin protein in ovarian follicle cells. Not less than three eggs were observed in each group. Of note, one more day is added and there are 9 days in the first reproductive period under dsRNA injection condition. Data are mean ± sd, the differences were analyzed by two-tailed Student’s t test. Source data are provided as a Source Data file.