Corn and humans: recombination and linkage disequilibrium in two genomes of similar size.
Two species with genomes of almost identical size, maize and human, have different evolutionary histories, and as a result their genomes differ greatly in their content of retroelements, average size of the genes and amount of genetic diversity. However, there are also significant similarities: they both have undergone bottlenecks during their recent history and seem to have non-uniform distribution of recombination events. The human genome has been shown to contain large linkage blocks characterized by a limited number of haplotypes. A similar linkage block structure is likely to exist in maize. Although highly diverse maize populations show rapid decline of linkage disequilibrium, as in humans, it is possible to define populations with strong linkage disequilibrium, suitable for whole-genome scan association mapping. The genetic diversity and lack of sequence homology found in maize influences recombinational properties and local linkage disequilibrium levels but also challenges our understanding of the relationship between the genome sequence and species definition.
Rafalski
Antoni
A
DuPont Crop Genetics, Experimental Station E353, PO Box 80353, Wilmington DE 19880-0353, USA. j-antoni.rafalski@cgr.dupont.com
Morgante
Michele
M
D000483:Alleles; D005787:Gene Frequency / Q000235:genetics*; D014644:Genetic Variation / Q000235:genetics; D005828:Genetics, Population; D016678:Genome; D006801:Humans; D015810:Linkage Disequilibrium / Q000235:genetics*; D011995:Recombination, Genetic / Q000235:genetics; D003313:Zea mays / Q000235:genetics*