Genes encoding the β1 subunit of voltage‐dependent Na+ channel in rat, mouse and human contain conserved introns

Abstract
We provide evidence in this study that the 86-bp insert in the β 1.2 mRNA isoform of the voltage gated sodium channel is an intron. Transcripts still retaining this intron were detected in all tissues where the β 1 gene expression was investigated. We also show that the exon/intron boundaries of the last two introns are conserved among rat, mouse and human β 1 gene. Unlike the highly conserved cDNAs, introns in only the rat and mouse genes are highly related. The last intron is very short (86–90 bp) and is located in the 3′ untranslated sequence, both uncommon properties of mammalian pre-mRNA introns.