title: Selective constraint in intergenic regions of human and mouse genomes.
abstract: We aligned and analyzed 100 pairs of complete, orthologous intergenic regions from the human and mouse genomes (average length approximately 12 000 nucleotides). The alignments alternate between highly similar segments and dissimilar segments, indicating a wide variation of selective constraint. The average number of selectively constrained nucleotides within a mammalian intergenic region is at least 2000. This is threefold higher than within a nematode intergenic region and at least twofold higher than the number of selectively constrained nucleotides coding for an average protein. Because mammals possess only two- to threefold more proteins than Caenorhabditis elegans, the higher complexity of mammals might be primarily because of the functioning of intergenic DNA.
authors: National Center of Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA. shabalin@ncbi.nlm.nih.gov
authors: S A
authors: SA
authors: Shabalina
authors: A Y
authors: AY
authors: Ogurtsov
authors: V A
authors: VA
authors: Kondrashov
authors: A S
authors: AS
authors: Kondrashov
mesh_terms: D000818:Animals; D001483:Base Sequence; D019295:Computational Biology; D021901:DNA, Intergenic / Q000235:genetics*; D019143:Evolution, Molecular; D016678:Genome; D023281:Genomics; D006801:Humans; D051379:Mice / Q000235:genetics*; D008969:Molecular Sequence Data; D012641:Selection, Genetic; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid
chemical_list: D021901:DNA, Intergenic