Alternative forms of murine TfR2 transcripts.

Using primers for 5′ and 3′ ends of the murine TfR2 coding region, the transcripts were amplified by RT-PCR, cloned, sequenced, and compared with the genomic sequences. The sequences of the primers are 5′-CACAAGCATGGAGCAACGTTGG-3′ and 5′-AGGGAGAAAGGAGAATCACGTGG-3′. Type 1 is the representative form, which is identical to that cloned by 5′ and 3′ RACE. Type 2 is a longer form that has additional sequences (intron 5 in the type 1) between exons 5 and 6. Type 3 is a shorter form that lacks exon 2. Sequences after exon 6 were the same in all 3 types, so only the 5′ portion of this gene (exons 1-6) is shown in this figure.