Genetics, Vol. 179, 527-537, May 2008, Copyright © 2008
doi:10.1534/genetics.107.081497

Linkage Disequilibrium Under Genetic Hitchhiking in Finite Populations

Ludwig-Maximilians University, Biocenter, 82152 Planegg, Germany

1 Corresponding author: Mathematical Institute, Albert-Ludwigs University, Eckerstrasse 1, D-79104 Freiburg, Germany.
E-mail: peter.pfaffelhuber{at}stochastik.uni-freiburg.de

The model of genetic hitchhiking predicts a reduction in sequence diversity at a neutral locus closely linked to a beneficial allele. In addition, it has been shown that the same process results in a specific pattern of correlations (linkage disequilibrium) between neutral polymorphisms along the chromosome at the time of fixation of the beneficial allele. During the hitchhiking event, linkage disequilibrium on either side of the beneficial allele is built up whereas it is destroyed across the selected site. We derive explicit formulas for the expectation of the covariance measure D and standardized linkage disequilibrium Formula between a pair of polymorphic sites. For our analysis we use the approximation of a star-like genealogy at the selected site. The resulting expressions are approximately correct in the limit of large selection coefficients. Using simulations we show that the resulting pattern of linkage disequilibrium is quickly—i.e., in <0.1N generations—destroyed after the fixation of the beneficial allele for moderately distant neutral loci, where N is the diploid population size.


Related articles in Genetics:

ISSUE HIGHLIGHTS

Genetics 2008 179: NP. [Full Text]  



This article has been cited by other articles:


Home page
Mol Biol EvolHome page
N. Svetec, P. Pavlidis, and W. Stephan
Recent Strong Positive Selection on Drosophila melanogaster HDAC6, a Gene Encoding a Stress Surveillance Factor, as Revealed by Population Genomic Analysis
Mol. Biol. Evol., July 1, 2009; 26(7): 1549 - 1556.
[Abstract] [Full Text] [PDF]


Home page
GeneticsHome page
S. Boitard, C. Schlotterer, and A. Futschik
Detecting Selective Sweeps: A New Approach Based on Hidden Markov Models
Genetics, April 1, 2009; 181(4): 1567 - 1578.
[Abstract] [Full Text] [PDF]