Консервативность сигнала альтернативного сплайсинга UGCAUG в геномах человека и мыши

It has recently been shown that the sequence UGCAUG occurred in introns downstream of brain-specific cassette exons more often than in a control sample of introns following constitutive exons. Here we analyzed conservation of all UGCAUG hexanucleotides observed in 1000 nucleotide segments following cassette exons. Some 50% of UGCAUG sites in the human introns and 70% sites from mouse introns were conserved in both genomes. Since conservation is a feature of functionally important genomic regions (e.g., protein-coding or regulatory regions), it is likely that the conserved sites are functional and regulate alternative splicing. Besides, analysis of newly available mRNA and EST data demonstrated that the considered exons are not strictly brain-specific, and thus UGCAUG appears to be an enhancer of exon inclusion not only in the brain, but also in other tissues.