This study investigated pine pollen (PP) as a safe, eco-friendly alternative to the synthetic hormone 17-methyltestosterone (MT) for inducing female-to-male sex reversal in Nile tilapia. Researchers fed three-day-old all-female fry either a standard diet, a diet with MT, or a diet supplemented with pine pollen for 30 days. Both the pine pollen and MT treatments successfully triggered female-to-male sex changes between 21 and 45 days post-hatch, resulting in significantly higher male populations (77.8% for PP and 97.8% for MT). Histological and genetic analysis revealed that pine pollen achieves this by up-regulating male-specific genes (dmrt1 and amh), down-regulating female genes (cyp19a1a and foxl2), and raising male sex hormones (testosterone and 11-ketotestosterone). While MT resulted in faster and more complete masculinisation, the study concludes that pine pollen successfully drives sex reversal by shifting the fish’s natural androgen-to-estrogen balance, though further optimization is needed to match the potency of the synthetic alternative.
Source : https://link.springer.com/article/10.1186/s13293-026-00950-5
