title: Detection of gene expression changes at chromosomal rearrangement breakpoints in evolution.
abstract: BACKGROUND
  We study the relation between genome rearrangements, breakpoints and gene expression. Genome rearrangement research has been concerned with the creation of breakpoints and their position in the chromosome, but the functional consequences of individual breakpoints remain virtually unknown, and there are no direct genome-wide studies of breakpoints from this point of view. A question arises of what the biological consequences of breakpoint creation are, rather than just their structural aspects. The question is whether proximity to the site of a breakpoint event changes the activity of a gene.
  
  
  RESULTS
  We investigate this by comparing the distribution of distances to the nearest breakpoint of genes that are differentially expressed with the distribution of the same distances for the entire gene complement. We study this in data on whole blood tissue in human versus macaque, and in cerebral cortex tissue in human versus chimpanzee. We find in both data sets that the distribution of distances to the nearest breakpoint of "changed expression genes" differs little from this distance calculated for the rest of the gene complement. In focusing on the changed expression genes closest to the breakpoints, however, we discover that several of these have previously been implicated in the literature as being connected to the evolutionary divergence of humans from other primates.
  
  
  CONCLUSIONS
  We conjecture that chromosomal rearrangements occasionally interrupt the regulatory configurations of genes close to the breakpoint, leading to changes in expression.
authors.affiliation: School of Information Technology & Engineering, University of Ottawa, Ottawa, K1N 6N5, Canada. adri.embo@gmail.com
authors.forename: Adriana
authors.initials: A
authors.lastname: Muñoz
authors.forename: David
authors.initials: D
authors.lastname: Sankoff
mesh_terms: D000818:Animals; D005075:Biological Evolution; D001773:Blood Cells / Q000378:metabolism; D002540:Cerebral Cortex / Q000378:metabolism; D002522:Chlorocebus aethiops; D056905:Chromosome Breakpoints; D033481:Chromosomes, Mammalian; D015870:Gene Expression; D016678:Genome; D006801:Humans; D008252:Macaca fascicularis; D002679:Pan troglodytes; D010802:Phylogeny; D011323:Primates / Q000235:genetics*