Fig. 12

17α-ethinylestradiol (EE2) fails to induce ovarian development in triploid zebrafish (A). Differentially expressed genes (DEGs) in EE2-treated triploids (3n + EE2) compared to triploid controls (3n). DEGs consisted of dehydrogenase/reductase member 3a (dhrs3a), cytochrome P450 family 26 subfamily B member 1 (cyp26b1), cytochrome P450 family 11 subfamily A member 1 (cyp11a1), cytochrome P450 family 17 subfamily A member 1 (cyp17a1), insulin-like 3 (insl3), and naked cuticle homolog 3-like (nkd3l). Asterisks denote significant differences between treatments. Normalized counts and statistical significance were obtained using DESeq2 median of ratios normalization and negative binomial differential expression modeling. (B). Inferred gene regulatory network in the gonads of 3n + EE2 zebrafish at 120 days post-fertilization compared with 3n controls. EE2 exposure enhanced retinoic acid (RA) degradation through upregulation of cyp26b1 and substrate limitation via dhrs3a, and indirectly through insl3 downregulation. Increased RA breakdown and reduced RA synthesis likely promoted testicular development while suppressing ovarian pathways, even under EE2 treatment. At the same time, altered insl3 expression may have impaired spermatogenesis, contributing to the reduced number of spermatocysts and spermatozoa. Additionally, the known stimulatory effect of estradiol on spermatogonial proliferation may have contributed to the increased abundance of spermatogonia. Upward/downward arrows indicate up- or downregulation of the adjacent gene; colored solid lines denote upregulation, colored dashed lines downregulation, and grey lines genes not differentially expressed but active in baseline gonadal physiology. Line endings denote stimulatory or inhibitory interactions. Abbreviations: spermatogonia An undifferentiated (SpgAund), spermatogonia A differentiated (SpgAdiff), spermatogonia B (SpgB), spermatocyte (Spc), spermatid (Spt), spermatozoa (Stz). Created in BioRender. MARTINEZ, A. (2025) https://BioRender.com/q3sjavl.