cDNA cloning and expression of a novel estrogen receptor β-subtype in goldfish (Carassius auratus)

摘要

We have isolated a second goldfish estrogen receptor (ER) β-subtype (gfER-β2) cDNA which is distinct from the liver-derived ER-β (gfER-β1) cDNA reported previously. The 2650-bp cDNA, isolated from a goldfish pituitary and brain cDNA library, encodes a 610 amino acid (aa) protein which shows only a 53% aa sequence identity with gfER-β1 in overall structure. RT-PCR analysis showed that mRNA of gfER-β2, in contrast to that of gfER-β1, was predominantly expressed in pituitary, telencephalon and hypothalamus as well as in liver of female goldfish. The existence of a second distinct ER-β subtype opens new dimensions for studying tissue-specific regulation of gene expression by estrogen in the tetraploid goldfish.