Fig. 9.

Role of TGIF1 in epithelial maintenance and JCM formation. In chicken ovaries (top), activation of the ERα signaling pathway by estrogens induces (directly or indirectly) the expression of TGF1 in the gonadal epithelium, resulting in epithelial structure maintenance and formation of the JCM by increased EMT. In chicken testis (bottom), TGIF1 expression is not induced in the gonadal epithelial cells due to the lack of ERα signaling. This results in the epithelial flattening and the lack of JCM formation.