Human recombination hotspots: Before and after the HapMap project

Abstract

Due to the inherent difficulties of studying recombination in humans, meiotic recombination hotspots have been best characterised in model organisms such as Saccharomyces cerevisiae. However, several intriguing features of human recombination have been unveiled by new analytical methods, including significant differences in both crossover rate and distribution between individuals and across chromosomes. Furthermore, studies at the highest resolution have shown that human meiotic crossovers generally concentrate into local hotspots that separate the genome into a series of relatively recombinationally inert haplotype blocks. The HapMap project has taken advantage of this pattern of recombination and is characterising the haplotype structure of the entire human genome, primarily to aid genome-wide association studies of complex, common disease. HapMap has also provided a tool for population geneticists to investigate genome-wide patterns of historical recombination at varying levels of resolution. However, it is only from the direct, high-resolution analysis of recombination events that we can truly appreciate what is currently happening at specific hotspots, and gain valuable clues about the dynamics and mechanisms of human meiotic recombination, the evolution of hotspots and their effect on genome diversity and evolution. © 2007 Springer-Verlag Berlin Heidelberg.