Research Perspectives of Expression Regulation and Putative Functions of Aromatase and Steroidogenic Enzymes in Brain of Teleost Fish

XIANG Fu-sheng;HUANG Tian-qing;GU Wei;WANG Bing-qian;HU Chao;XU Ge-feng;Heilongjiang River Fisheries Research Institute, Chinese Academy of Fishery Sciences;College of Fisheries and Life Sciences, Shanghai Ocean University;Dujiangyan Administration of Sichuan Province;

brain aromatase;;sex differentiation;;fish brain;;steroidogenic enzyme

Unlike mammals, Cyp19a,one of aromatase(Cyp19)is most strongly expressed in the brain of teleost fish, which is primarily derived from gonad aromatase and brain aromatase, and highly expressed in gonad and brain. Brain aromatase is found to be only expressed in radial glial cells(RGC), which acts as progenitor cells from first to last in the development of larval and adult brain throughout the life cycle of fishes, using transgenic fish(cyp19a1b-GFP)for in situ hybridization, immunohistochemistry and expression of green fluorescent protein(GFP). The aromatase is mainly distributed in the preoptic area and hypothalamus, as well as in the central nervous system and spinal cord. The high expression of Cyp19a1b is observed by the regulation of aromatase expression by estrogen and aromatic androgen, and the expression mechanism is derived from the combination of estrogen receptors and estrogen responsive components of the Cyp19a1b promoter. The specificity of the cells is conducted through the cooperation between estrogen receptor and specific glial factors. The adult brain aromatase has the classic function of the brain sex differentiation and sexual behavior,and is involved in expression in radial glial cells, which might be an important mechanism to maintain high activity in fish brain.