Identification of C-terminally and N-terminally truncated estrogen receptor α variants in the mouse.

We re-examined mouse ERα mRNA variants using rapid amplification of cDNA ends (RACE) and RT-PCR. Our analysis showed the presence of several mRNA variants containing unique 5'- or 3'-nucleotide sequences. We mapped the cDNA sequences on the mouse genome, and identified four novel 3'-terminal and 5'-leader exons in the intronic region between exons 4 and 5.