Chromosome-wide distribution of haplotype blocks and the role of recombination hot spots.
Phillips MS., Lawrence R., Sachidanandam R., Morris AP., Balding DJ., Donaldson MA., Studebaker JF., Ankener WM., Alfisi SV., Kuo F-S., Camisa AL., Pazorov V., Scott KE., Carey BJ., Faith J., Katari G., Bhatti HA., Cyr JM., Derohannessian V., Elosua C., Forman AM., Grecco NM., Hock CR., Kuebler JM., Lathrop JA., Mockler MA., Nachtman EP., Restine SL., Varde SA., Hozza MJ., Gelfand CA., Broxholme J., Abecasis GR., Boyce-Jacino MT., Cardon LR.
Recent studies of human populations suggest that the genome consists of chromosome segments that are ancestrally conserved ('haplotype blocks'; refs. 1-3) and have discrete boundaries defined by recombination hot spots. Using publicly available genetic markers, we have constructed a first-generation haplotype map of chromosome 19. As expected for this marker density, approximately one-third of the chromosome is encompassed within haplotype blocks. Evolutionary modeling of the data indicates that recombination hot spots are not required to explain most of the observed blocks, providing that marker ascertainment and the observed marker spacing are considered. In contrast, several long blocks are inconsistent with our evolutionary models, and different mechanisms could explain their origins.