eLife Assessment
This is an overall compelling set of findings on the role of centrally produced estrogens in the control of behaviors in male medaka. The significance of the findings rests on the revealed potential mechanism between brain derived estrogens modulating social behaviors in males , supported by the analysis of multiple transgenic lines. The evidence for the broader claim is incomplete since it has not been extended to female medaka, and further experimentation would be necessary to fully validate the conclusions on the role of brain-derived estrogens. Nonetheless, the findings have led to important hypotheses on the hormonal control of behaviors in teleosts that can be tested further.