Fig. 7: Schematic view of the regulatory effect of DNMT1 on reproduction in B. germanica.

a In wild-type females (left panel), DNMT1-mediated DNA methylation in the promoter region of the ftz-f1 was able to repress ftz-f1 expression at suitable levels during choriogenesis. At its normal expression level, ftz-f1 plays important roles in ovarian development, including the maturity of sponge-like bodies. b In dsDnmt1-treated females (right panel), hypomethylation-induced ftz-f1 upregulation impairs choriogenesis and disrupts fertilization by causing aberrantly high levels of 20E titer and 20E signaling, excessive follicle cell dissociation, and a shortage of chorion proteins.