title: Diversity in G + C content at the third position of codons in vertebrate genes and its cause.
abstract: Correlation was positive between the G + C content at the codon third position in genes of vertebrates and the G + C content of the genome portion surrounding each gene. Exons of genes with a high G + C% at the codon 3rd position are surrounded by G + C-rich introns and G + C-rich flanking sequences, and those with a low G + C% at the position by A + T-rich introns and flanking sequences. Analysis of G + C content distribution along DNA sequences using a DNA Sequence Data Bank supported the view that the vertebrate genome is a mosaic of regions with clear differences in their G + C content. The biological significance of the variation in G + C content throughout the vertebrate genome is discussed in connection with chromosomal banding.
mesh_terms: D000818:Animals; D001482:Base Composition; D001483:Base Sequence; D002645:Chickens; D003062:Codon; D005796:Genes; D014644:Genetic Variation; D006801:Humans; D012333:RNA, Messenger; D013045:Species Specificity; D014714:Vertebrates / Q000235:genetics*
chemical_list: D003062:Codon; D012333:RNA, Messenger