Guinea pig <i>Abcb1</i> gene, transcripts and C-terminal amino acid differences.

<p>A. Guinea pig <i>Abcb1</i> locus showing the relative localization of exons (bars) on the coding (minus) strands and in the 5′- to -3′ (left-right) orientation relative to that of the corresponding human <i>ABCB1</i> locus (above). Dashed lines join highly homologous exons. Diagram drawn to scale. Stars indicate major differences between guinea pig and human P-gp, including the absence of the first two exons, a 2.8 kb exon 29, and the presence of two additional terminal exons, exons 30 and 31. Diagonal lines between exons 30 and 31 represent a longer region than can be represented here. B. Composition of guinea pig <i>ABCB1</i> transcripts following alternate exon usage and alternative splicing. Note that exons 3 to 28 are common to all three isoforms. Dotted lines represent spliced junctions; Met represents start codon (AUG); Hexagons represent stop codons (UAA). Diagram drawn to scale. C. The 4 carboxy terminal amino acids of the guinea pig P-gp proteins according to <i>in silico</i> translation. R– = the rest of the protein; -COOH = the carboxylic acid tail. Note that diagrams based on results returned from <i>BLAST</i> or <i>BLAT</i> against the UCSC 2008 guinea pig genome assembly change periodically as the assembly evolves; hence, results regarding nucleotide sequences especially intron sizes are subject to change.