Nonrandom localization of recombination events in human alpha satellite repeat unit variants: implications for higher-order structural characteristics within centromeric heterochromatin.


Journal Article

Tandemly repeated DNA families appear to undergo concerted evolution, such that repeat units within a species have a higher degree of sequence similarity than repeat units from even closely related species. While intraspecies homogenization of repeat units can be explained satisfactorily by repeated rounds of genetic exchange processes such as unequal crossing over and/or gene conversion, the parameters controlling these processes remain largely unknown. Alpha satellite DNA is a noncoding tandemly repeated DNA family found at the centromeres of all human and primate chromosomes. We have used sequence analysis to investigate the molecular basis of 13 variant alpha satellite repeat units, allowing comparison of multiple independent recombination events in closely related DNA sequences. The distribution of these events within the 171-bp monomer is nonrandom and clusters in a distinct 20- to 25-bp region, suggesting possible effects of primary sequence and/or chromatin structure. The position of these recombination events may be associated with the location within the higher-order repeat unit of the binding site for the centromere-specific protein CENP-B. These studies have implications for the molecular nature of genetic recombination, mechanisms of concerted evolution, and higher-order structure of centromeric heterochromatin.

Full Text

Cited Authors

  • Warburton, PE; Waye, JS; Willard, HF

Published Date

  • October 1993

Published In

Volume / Issue

  • 13 / 10

Start / End Page

  • 6520 - 6529

PubMed ID

  • 8413251

Pubmed Central ID

  • 8413251

Electronic International Standard Serial Number (EISSN)

  • 1098-5549

International Standard Serial Number (ISSN)

  • 0270-7306

Digital Object Identifier (DOI)

  • 10.1128/mcb.13.10.6520


  • eng