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

We have isolated a second goldfish estrogen receptor (ER) beta-subtype (gfE R-beta 2) cDNA which is distinct from the liver-derived ER-beta (gfER-beta 1) cDNA reported previously. The 2650-bp cDNA, isolated from a goldfish pit uitary and brain cDNA library, encodes a 610 amino acid (aa) protein which shows only a 53% aa sequence identity with gfER-beta 1 in overall structure . RT-PCR analysis showed that mRNA of gfER-beta 2, in contrast to that of g fER-beta 1, was predominantly expressed in pituitary, telencephalon and hyp othalamus as well as in liver of female goldfish. The existence of a second distinct ER-beta subtype opens new dimensions for studying tissue-specific regulation of gene expression by estrogen in the tetraploid goldfish. (C) 2000 Elsevier Science B.V. All rights reserved.