The Effect of Gene Conversion on Intralocus Associations

Open Access
Publisher Website
Google Scholar
Abstract
SEVERAL predictions of the genomic pattern of nucleotide polymorphism include the local recombination rate, r, as a parameter. In typical population genetic models, the parameter r, for two specified loci (or sites), is properly defined as the probability that a randomly selected gamete produced by a double heterozygote is a recombinant. In a given region, r can be measured directly through genetic crosses. This is typically done by observing markers spaced several centimorgans apart, in which case recombinants are produced almost exclusively by classical crossing-over. Over small intervals it may be assumed that crossing-over events are equally likely to occur at any point between two markers, and the probability of observing more than one can be neglected. Thus r, to a reasonable approximation, increases linearly over short physical distances. The problem we wish to draw attention to is that this model is often extrapolated to distances far too small to ignore the added effect of gene conversion events on the overall probability of producing a recombinant.