Tissue-specific expression of multiple mRNA variants of the mouse estrogenreceptor alpha gene

The isolation of five new mouse estrogen receptor cc. mRNA variants (mER al pha. A, B, F1, F2 and H) is described. All of these transcripts are generat ed by alternative splicing and all encode the 66 kDa ER alpha protein that the previously identified mRNA C variant generates. However, these transcri pts differ in their 5' untranslated regions. RT-PCR and S1 nuclease protect ion assays revealed a tissue- and sex-specific expression pattern of all va riants. 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 l iver, 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 comple x genomic unit in mice that exhibits alternative splicing which is regulate d in a tissue-specific manner. (C) 2000 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.