Tissue-specific expression of multiple mRNA variants of the mouse estrogen receptor α gene

The isolation of five new mouse estrogen receptor cc. mRNA variants (mER alpha. A, B, F1, F2 and H) is described. All of these transcripts are generated by alternative splicing and all encode the 66 kDa ER alpha protein that the previously identified mRNA C variant generates. However, these transcripts differ in their 5' untranslated regions. RT-PCR and S1 nuclease protection assays revealed a tissue- and sex-specific expression pattern of all variants. The C and F mRNA variants are the predominantly expressed mER alpha. variants in mouse. The expression of mER alpha. H mRNA is restricted to liver, although female mice produce around a five fold higher level of this transcript than males. Our results show that the mER alpha gene is a complex genomic unit in mice that exhibits alternative splicing which is regulated in a tissue-specific manner. (C) 2000 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.