Figure 5. Cross-species sequence conservation of proximal intron 15 of the Nfκb1 gene.

A. ClustalW alignment (EBI) of Nfκb1 intron 15 sequences from different species (shown at the left of the alignment). The reference mouse sequence from B6 is shown on top, including the single letter amino acid code for the polypeptide segment coded by exon 15. The genomic sequence of A is shown exactly as in Fig. 3B, including the deleted 54 bp duplication (‘---’) and the 3-repeat DNA motif overlapping the 3′ splice site of exon 15 (Arrows). Both mouse sequences (B6 and A) have been aligned to corresponding rat, dog, horse and human genomic sequences. Conservation of each mouse nucleotide is represented as shaded boxes at the bottom with high (black) to low (white) level conservation. B. Nfκb1 cDNA sequence encoded by exon 13 to exon 17 (displayed as alternating underlined and regular format for each exon) of mouse and human genes have been aligned. The least conserved portion of the sequence is that encoded by exon 15, which sequence is in bold characters. Conserved nucleotides across the sequence are identified (*).