Satellite DNA

repetitive DNA with distinct base composition observed using isopycnic centrifugation.

Satellite DNA has many sections of repeating, non-coding DNA.

Satellite DNA is a type of tandem repeat. The repeats sit next to each other, in tandem. These are multiple copies of the same base-pair sequence lying end-to-end.[1][2][3] Tandem repeats also include minisatellite and microsatellite DNA. Satellite DNA is the main component of centromeres. It forms the main part of heterochromatin.[4][5]

The most common type of tandem repeat is the heterochromatin, which sits on chromosomes around the centromeres and elsewhere. It is "transcriptionally inactive", meaning, it does not code for proteins.[6][7][8]

References change

  1. Burt A. & Trivers R. 2006. Genes in conflict: the biology of selfish genetic elements. Harvard University Press. "Tandem Repeats" p364/6 & p582.
  2. "Copies of base-pair sequences may be repeated one after another along a chromosome: for example the 40S rRNA genes in somatic cells of toads, of which there are about 500 copies". Adapted from [1]
  3. Tandem Repeat at the US National Library of Medicine Medical Subject Headings (MeSH) [2]
  4. Knight, Julian C. (2009). Human genetic diversity: functional consequences for health and disease. Oxford University Press. p. 167. ISBN 978-0-19-922769-3.
  5. satellite DNA at Dorland's Medical Dictionary
  6. King R.C et al 2006. A dictionary of genetics. 7th ed, Oxford University Press, p202/3.
  7. Myers P.Z. 2007. Tandem repeats and morphological variation. Scitable. [3]
  8. Alberts, Bruce et al 2002. Molecular biology of the cell. Garland, G31.