Aromatase, brain sexualization and plasticity: the fish paradigm
| Autor: | Isabelle Anglade, Colette Vaillant, Elisabeth Pellegrini, Yohann Mérot, Nicolas Diotel, Yann Le Page, Olivier Kah |
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| Rok vydání: | 2010 |
| Předmět: |
0303 health sciences
medicine.medical_specialty Gonad Sexual differentiation medicine.drug_class General Neuroscience Neurogenesis Biology Radial glial cell 03 medical and health sciences 0302 clinical medicine medicine.anatomical_structure Endocrinology Estrogen Sex steroid Internal medicine medicine biology.protein Aromatase 030217 neurology & neurosurgery 030304 developmental biology Sex characteristics |
| Zdroj: | European Journal of Neuroscience. 32:2105-2115 |
| ISSN: | 0953-816X |
| DOI: | 10.1111/j.1460-9568.2010.07519.x |
| Popis: | In contrast to mammals, teleost fish have a very labile genetic sex determination. Sex differentiation is influenced by a combination of hormonal, social and environmental factors and teleost fishes exhibit many examples of hermaphroditism. This means that the brain of fish is not irreversibly sexualized early in life. This review aims at highlighting some unique features of fish that may explain their brain sexual plasticity. Unlike mammals, in which brain aromatase activity decreases after birth, adult teleosts exhibit an intense aromatase activity due to strong expression of one of two aromatase genes (aromatase A or cyp19a1a and aromatase B or cyp19a1b) that arose from a gene duplication event. Interestingly, aromatase B is only expressed in radial glial cells (RGC) of adult fish. These cells persist throughout life and act as progenitors in the brain of both developing and adult fish. In agreement with the fact that brain aromatase activity is correlated with sex steroid levels, the high expression of cyp19a1b is due to an autoregulatory loop through which estrogens and aromatizable androgens upregulate aromatase expression. Given the well-established roles of estrogens and aromatase on brain sexualization, these features suggest that the brain of fish conserves properties of embryonic mammalian brain throughout life - high neurogenic activity and high aromatase expression in progenitor cells correlated with sex steroid levels. The permanent dialogue between the brain and the gonad would permit sex changes and thus the emergence of a variety of reproductive strategies. Other hypotheses are also discussed. |
| Databáze: | OpenAIRE |
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