African-derived South American populations: A history of symmetrical and asymmetrical matings according to sex revealed by bi- and uni-parental genetic markers

Abstract

Estimates of African, European, and Amerindian contributions to the gene pool of 11 predominantly African‐derived South American populations were obtained using five autosomal and one Y chromosome hypervariable loci, as well as mitochondrial DNA (sequences of the first hypervariable segment of the control region, plus two restriction sites and the presence or absence of the CoII/tRNALys intergenic 9‐bp deletion). The three latter characteristics are reported here for the first time for 42 individuals living in three Brazilian populations. Thirty‐eight sequences were identified in these persons; 17 (45%) could be classified as being of African, 4 (11%) of Amerindian, and 2 (5%) of European origin. Evidence for asymmetrical matings in relation to sex and ethnic group was obtained for nine of the 11 populations. The most consistent finding was the introduction of European genes through males, but the results differ in the several communities, indicating the importance of local factors in such interactions. Am. J. Hum. Biol. 11:551–563, 1999. © 1999 Wiley‐Liss, Inc.

Allele frequency distributions of six hypervariable loci (D1S80, APOB, D4S43, vW1, F13A and DYS19) in two African-Brazilian communities from the Amazon region

“…Based on hypervariable loci analysis, the African contribution to the Curiau gene pool was 30% lower than that estimated by protein loci, and the latter did not detect any Amerindian component whatsoever. Significant differences between the admixture estimates obtained with these hypervariable and with protein loci were also observed by Bortolini et al (1999) in three South American populations of African descent. Once again, in some populations, the Amerindian components were only identified by the autosomal hypervariable loci.…”

“…Admixture estimates for Pacoval and Curiau were calculated by the gene identity method (Chakraborty, 1985), using the ADMIX3 program. The parental allele frequencies used in the interethnic admixture estimates were obtained from Bortolini et al (1999).…”

Genetic affinity and admixture of northern Thai people along their migration route in northern Thailand: evidence from autosomal STR loci

“…7 Admixture, the genetic consequence of mixing between genetically differentiated populations, resulting from geographical, ecological or cultural separation, is common in human evolution. Pioneering research on genetic admixture of human populations was mainly been applied to African-Americans, [12][13][14][15] Latin-Americans, 16 Europeans [17][18] and East Asians, [19][20][21] but has been limited in Southeast Asia.…”

Admixture in Mexico City: implications for admixture mapping of Type 2 diabetes genetic risk factors

“…This approach, known as admixture mapping (AM), is analogous to linkage analysis of an experimental cross between inbred strains (Halder and Shriver 2003;Hoggart et al 2004;Patterson et al 2004; Montana and Pritchard 2004;Nievergelt and Schork 2005;Smith and O'Brien 2005). Populations with a recent history of admixture (eg., less than 20 generations ago), such as many populations in North, Central and South America and the Caribbean are ideally suited for admixture mapping (Hanis et al 1991;Parra et al 1998;Bortolini et al 1999;Mesa et al 2000). The history of admixture of each population determines the density of the map required as well as the mapping resolution Patterson et al 2004).…”