Stress and sex determination in fish: From brain to gonads

CASTAÑEDA CORTÉS, D.C.; FERNANDINO, J.I.

INTERNATIONAL JOURNAL OF DEVELOPMENTAL BIOLOGY

U B C PRESS

Año: 2021 vol. 65 p. 207 - 214

0214-6282

Fish present remarkable malleability regarding gonadal sex fate. This phenotypic plasticity enables an organism to adapt changes in the environment by responding with different phenotypes. The gonad and the brain present this extraordinary plasticity. These organs are involved in the response to environmental stressors to direct the gonadal fate, inducing sex change or sex reversal in hermaphroditic and gonochoristic fish, respectively. The presence of such molecular and endocrine plasticity gives this group a large repertoire of possibilities against a continuously changing environment, resulting in the highest radiation of reproduction strategies described in vertebrates. In this review, we provide a broad and comparative view of tremendous radiation of sex determination mechanisms to direct gonadal fate. New results have established that the driving mechanism involves early response to environmental stressors by the brain plus high plasticity of gonadal differentiation and androgens as by-products of stress inactivation. In addition to the stress axis, another two major axes ? the hypothalamic-pituitary-gonadal axis and the hypothalamic-pituitary-thyroid axis, which are well known to participate in the regulation of reproduction ? have been proposed as reinforcing the brain-gonadal interrelationships in the fate of the gonad.