Detection of intron 8 transcripts of the mGR gene. A, Genomic organization (not to scale) of the mGR gene, showing location of forward primer (exon 7) and reverse primers (1,2,3,4,5) used for RT-PCR analysis. B, Predicted PCR product sizes for reverse primers 1–4 are indicated. Only primers in the intron 8 (I-8) region yielded products. In the case of primer 4, two products were predicted based on alternate utilization of a donor or acceptor site (Supplemental Fig. 1). Primers 4 and 5 (data not shown) yielded no products on several attempts, consistent with published results (25). UTR, Untranslated region; Con, amplification without template.