title: GC Content Heterogeneity Transition of Conserved Noncoding Sequences Occurred at the Emergence of Vertebrates.
abstract: Conserved non-coding sequences (CNSs) of Eukaryotes are known to be significantly enriched in regulatory sequences. CNSs of diverse lineages follow different patterns in abundance, sequence composition, and location. Here, we report a thorough analysis of CNSs in diverse groups of Eukaryotes with respect to GC content heterogeneity. We examined 24 fungi, 19 invertebrates, and 12 non-mammalian vertebrates so as to find lineage specific features of CNSs. We found that fungi and invertebrate CNSs are predominantly GC rich as in plants we previously observed, whereas vertebrate CNSs are GC poor. This result suggests that the CNS GC content transition occurred from the ancestral GC rich state of Eukaryotes to GC poor in the vertebrate lineage due to the enrollment of GC poor transcription factor binding sites that are lineage specific. CNS GC content is closely linked with the nucleosome occupancy that determines the location and structural architecture of DNAs.
authors.affiliation: Department of Genetics, School of Life Science, Graduate University for Advanced Studies (SOKENDAI), Mishima, Japan.|Division of Population Genetics, National institute of Genetics, Mishima, Japan.
authors.forename: Nilmini
authors.initials: N
authors.lastname: Hettiarachchi
authors.affiliation: Department of Genetics, School of Life Science, Graduate University for Advanced Studies (SOKENDAI), Mishima, Japan saitounr@nig.ac.jp.|Division of Population Genetics, National institute of Genetics, Mishima, Japan.
authors.forename: Naruya
authors.initials: N
authors.lastname: Saitou
mesh_terms: D000818:Animals; D001482:Base Composition; D001717:Birds / Q000235:genetics; D017124:Conserved Sequence; D019143:Evolution, Molecular; D005399:Fishes / Q000235:genetics; D005658:Fungi / Q000235:genetics; D007448:Invertebrates / Q000235:genetics; D012045:Regulatory Sequences, Nucleic Acid; D012104:Reptiles / Q000235:genetics
keywords: CNS; conserved non-coding sequence; fungi; invertebrates; vertebrates