Molecular cloning and expression of three estrogen receptors in the protogynous wrasse, Halichoeres trimaculatus
Estrogens are essential for sex change and behavior in wrasses. To understand the molecular mechanisms of estrogen action in the reproduction of the protogynous wrasse, Halichoeres trimaculatus, we isolated cDNA encoding three estrogen receptor (ER) subtypes from ovary by 5’ and 3’ rapid amplification cDNA ends (RACE) methods. The deduced amino acid sequence of ERα, ERb1 and ERb2 showed high identity to the red seabream ERα (81%), largemouth bass ERb (82%) and largemouth bass ERγ (81%), respectively. Real-time polymerase chain reaction revealed some distinctions in tissue expression of ERs, suggesting different functions for each ER subtype in protogynous wrasses.