title: An unusual 500,000 bases long oscillation of guanine and cytosine content in human chromosome 21.
abstract: An oscillation with a period of around 500 kb in guanine and cytosine content (GC%) is observed in the DNA sequence of human chromosome 21. This oscillation is localized in the rightmost one-eighth region of the chromosome, from 43.5 Mb to 46.5 Mb. Five cycles of oscillation are observed in this region with six GC-rich peaks and five GC-poor valleys. The GC-poor valleys comprise regions with low density of CpG islands and, alternating between the two DNA strands, low gene density regions. Consequently, the long-range oscillation of GC% result in spacing patterns of both CpG island density, and to a lesser extent, gene densities.
authors.affiliation: The Robert S. Boas Center for Genomics and Human Genetics, North Shore LIJ Institute for Medical Research, 350 Community Drive, Manhasset, NY 11030, USA. wli@nslij-genetics.org
authors.forename: Wentian
authors.initials: W
authors.lastname: Li
authors.forename: Dirk
authors.initials: D
authors.lastname: Holste
mesh_terms: D001482:Base Composition; D020029:Base Pairing; D002891:Chromosomes, Human, Pair 21 / Q000235:genetics*; D003596:Cytosine / Q000378:metabolism*; D004247:DNA / Q000235:genetics; D006147:Guanine / Q000378:metabolism*; D006801:Humans
chemical_list: D006147:Guanine; D003596:Cytosine; D004247:DNA