title: Linkage disequilibrium patterns and genetic structure of Amerindian and non-Amerindian Brazilian populations revealed by long-range X-STR markers.
abstract: The extent of X-chromosome linkage disequilibrium (LD) was studied in a southern Brazilian population, and in a pool of samples from Amerindian populations. For this purpose, 11 microsatellites, located mostly in a Xq region comprising approximately 86 Mb was investigated. The lower Amerindian gene diversity associated with significant differences between the populations studied indicated population structure as the main cause for the higher LD values in the Amerindian pool. On the other hand, the LD levels of the non-Amerindian Brazilian sample, although less extensive than that of the Amerindians, were probably determined by admixture events. Our results indicated that different demographic histories have significant effects on LD levels of human populations, and provide a first approach to the X-chromosome ancestry of Amerindian and non-Amerindian Brazilian populations, being valuable for future studies involving mapping and population genetic studies.
authors.affiliation: Laboratório de Perícias, Instituto Geral de Perícias, Porto Alegre, RS, Brazil.
authors.forename: Fabio P N
authors.initials: FP
authors.lastname: Leite
authors.forename: Sidney E B
authors.initials: SE
authors.lastname: Santos
authors.forename: Elzemar M R
authors.initials: EM
authors.lastname: Rodríguez
authors.forename: Sidia M
authors.initials: SM
authors.lastname: Callegari-Jacques
authors.forename: Dario A
authors.initials: DA
authors.lastname: Demarchi
authors.forename: Luiza T
authors.initials: LT
authors.lastname: Tsuneto
authors.forename: M Luiza
authors.initials: ML
authors.lastname: Petzl-Erler
authors.forename: Francisco M
authors.initials: FM
authors.lastname: Salzano
authors.forename: Mara H
authors.initials: MH
authors.lastname: Hutz
mesh_terms: D000704:Analysis of Variance; D001938:Brazil; D041321:Chromosomes, Human, X / Q000235:genetics*; D005787:Gene Frequency; D014644:Genetic Variation; D005828:Genetics, Population; D006801:Humans; D007199:Indians, South American / Q000235:genetics*; D015810:Linkage Disequilibrium; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics