Intrachromosomal gene conversion and the maintenance of sequence homogeneity among repeated genes.

Intrachromosomal gene conversion is the non-reciprocal transfer of information between a pair of repeated genes on a single chromosome. This process produces eventual sequence homogeneity within a family of repeated genes. An evolutionary model for a single chromosome lineage was formulated and analyzed. Expressions were derived for the fixation probability, mean time to fixation or loss, and mean conditional fixation time for a variant repeat with an arbitrary initial frequency. It was shown that a small conversional advantage or disadvantage for the variant repeat (higher or lower probability of producing two variant genes by conversion than two wild-type genes) can have a dramatic effect on the probability of fixation. The results imply that intrachromosomal gene conversion can act sufficiently rapidly to be an important mechanism for maintaining sequence homogeneity among repeated genes.

Duke Scholars

Author Thomas Douglas Petes Molecular Genetics and Microbiology