Fig. 5: Bod1l-expression and H3K4me3-methylation in primordial gonads of B. viridis, i.e., in the female early ovary, and in male Bidder’s organ, contributing to the testes anlage (Gosner stages 36–37) as well as in early metamorphosis (Gosner stages 43–44).

Bod1l expression shown by RNA in-situ hybridization (ISH) on 20 µm transverse cryosections of female (a, d) and male (b, c, e, f, h) gonads at developmental stages Gosner 36–37 (a–c) and 43–44 (d–f), the latter presenting early metamorphic stages. DAPI was used to stain nuclei. Magenta asterisks indicate nuclei of germ cells; magenta arrows: cytoplasm of germ cells; yellow arrows: nuclei of somatic cells not stained by bod1l RNA ISH; green arrows: nuclei of somatic cells stained by bod1l RNA ISH. Yellow boxes in b and e indicate zoomed images shown in c and f, respectively. H3K4me3 and DAPI staining on 20 µm transverse cryosections of female (g) and male (h) green toad Bidder’s organ and gonads, Gosner stage 43–44. White asterisks indicate H3K4me3-positive germ cell nuclei; yellow boxes indicate somatic cells. Scale bars (a, b, d, e, g, h): 20 µm; (c, f) 5 µm. i Summary of bod1l-expression and H3K4me3-methylation in somatic cells and germ cells in Gosner stages 36–37 and 43–44 male and female gonads. For each Gosner stage, five sections from one gonad sample were analyzed in two independent experiments.