The effects of genotype-dependent recombination, and transmission asymmetry, on linkage disequilibrium

A recent sperm-typing study by Jeffreys and Neumann suggested that recombination rates in different individuals at the DNA2 recombination hotspot appeared to be highly dependent on their genotype at a particular A/G SNP, FG11. Specifically, individuals who carried at least one copy of the A allele at this SNP exhibited rates of crossover considerably higher than those of individuals with no copies. Further, recombinant sperm from heterozygous individuals showed a preferential tendency to carry the G allele. We consider the effects of these phenomena on patterns of linkage disequilibrium and find them to be more subtle than might have been expected. In particular, our analysis suggest that, perhaps surprisingly, patterns of LD among chromosomes carrying the "hot" allele (in case, A) will typically be similar to those among chromosomes carrying the "cold" allele (G).