Genetical-demographic data from two amazonian populations composed of descendants of african slaves: Pacoval and Curiau

Guerreiro, João Farias; Ribeiro-dos-Santos, Ândrea; Santos, Eduardo José Melo dos; Vallinoto, Antônio Carlos Rosário; Cayres-Vallinoto, Izaura Maria Vieira; Aguiar, Gilberto Ferreira de Souza; Santos, Sidney Emanuel Batista dos

doi:10.1590/s1415-47571999000200004

Cited by 38 publications

(22 citation statements)

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“…Previous studies using classic markers and/or autosomal STRs also suggest a high contribution of Amerindian genes in the Amazonian Afro-descent (Schneider et al 1987;Bortolini et al 1995;Guerreiro et al 1999;Cayres-Valinoto et al 2003). However, the high contribution of Amerindian genes in Afro-derived communities is not common in other regions of Brazil.…”

Section: Differentiation Between Populationsmentioning

confidence: 88%

“…These studies demonstrate that, depending on the genetic marker used, the contribution of African genes in different communities can vary greatly and that the contribution of European and Amerindian genes is significant (Schneider et al 1987;Guerreiro et al 1999;Ribeiro-dos-Santos et al 2002;Carvalho et al 2008), implying that population stratification may be present in all Afro-derived communities studied. Stratification occurs when a population is formed from a relatively recent admixture of subpopulations (European, African, and indigenous, for example) and when the proportion of this admixture varies between the individuals that make it up (Hoggart et al 2003).…”

Section: Afro-derived Amazonianmentioning

confidence: 98%

“…In Brazil, various studies have been conducted on Afro-derived groups in an attempt to estimate the contribution of parental populations to the formation of these populations, using classic genetic polymorphisms (Bortolini et al 1995;Arpini-Sampaio et al 1999;Guerreiro et al 1999), polymorphisms of nuclear DNA Silva Jr. et al 1999;Cayres-Vallinoto et al 2003); mitochondrial DNA markers Ribeiro-dos-Santos et al 2002;Carvalho et al 2008) and Y chromosome markers Kiyoko et al 2004). …”

Section: Afro-derived Amazonianmentioning

confidence: 99%

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Afro-Derived Amazonian Populations: Inferring Continental Ancestry and Population Substructure

et al. 2011

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A panel of Ancestry Informative Markers (AIMs) was used to identify population substructure and estimate individual and overall interethnic admixture in 294 individuals from seven African-derived communities of the Brazilian Amazon. A panel of 48 biallelic markers, representing the insertion (IN) or the deletion (DEL) of small DNA fragments, was employed for this purpose. Overall interethnic admixture estimates showed high miscegenation with other ethnic groups in all populations (between 46% and 64%). The proportion of ancestral genes varied significantly among individuals of the sample: the contribution of African genes varied between 12% and 75%; of European genes between 10% and 73%; and of Amerindians genes between 8% and 66%. The obtained data reveal a high contribution of Amerindian genes in these communities, unlike in other African-derived communities of the Northeast and the South of Brazil. In addition, the majority of the Amerindian contribution may result from the preferential inclusion of indigenous women in the African descent groups. High heterogeneity of the proportion of interethnic admixture among analyzed individuals was found when the proportion of ancestral genes of each individual of the sample was estimated. This heterogeneity is reflected in the fact that four populations can be considered as substructured and that the global African descent sample is possibly formed by two subpopulations. 46% and 64%). The proportion of ancestral genes varied significantly among individuals of the sample: the contribution of African genes varied between 12% and 75%; of European genes between 10% and 73%; and of Amerindians genes between 8% and 66%. The obtained data reveal a high contribution of Amerindian genes in these communities, unlike in other African-derived communities of the Northeast and the South of Brazil. In addition, the majority of the Amerindian contribution may result from the preferential inclusion of indigenous women in the African descent groups. High heterogeneity of the proportion of interethnic admixture among analyzed individuals was found when the proportion of ancestral genes of each individual of the sample was estimated. This heterogeneity is reflected in the fact that four populations can be considered as substructured and that the global African descent sample is possibly formed by two subpopulations. Keywords AMAZON, AIM, AFRICAN DESCENT, INDEL, POPULATION SUBSTRUCTUREThe Brazilian population is the product of the miscegenation of three main ethnic groups: Amerindians, Europeans, and Africans. It is estimated that approximately four million Africans were brought by force to Brazil as slaves between 1550 and 1870 (Klein 1986). The distinct geographical regions of Brazil received different numbers of African slaves, being greater in the Northeast and lower in the North (Santos and Guerreiro 1995). The arrival of African slaves to the Amazon began in the mid-17th century (1750). It is estimated that at least 53,000 Africans arrived in the Brazilian Amazon during the ...

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Section: Differentiation Between Populationsmentioning

confidence: 88%

Section: Afro-derived Amazonianmentioning

confidence: 98%

Section: Afro-derived Amazonianmentioning

confidence: 99%

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Afro-Derived Amazonian Populations: Inferring Continental Ancestry and Population Substructure

et al. 2011

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“…These differences may be due to sampling problems, but they nevertheless suggest that protein 238 Vallinoto et al Na: observed number of alleles; Ne: Effective number of alleles (Kimura and Crow, 1963); HWE = Hardy-Weinberg expectations; PIC = polymorphic information content. Guerreiro et al (1999) loci (or at least those used in this study) are less efficient than the autosomal hypervariable loci for the investigation of ethnic admixture.…”

Section: F13a1mentioning

confidence: 99%

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

Vallinoto

Valente

et al. 2003

Genet. Mol. Biol.

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The allele frequency distributions of three VNTR (D1S80, APOB and D4S43) and three STR (vW1, F13A1 and DYS19) loci were investigated in two Afro-Brazilian populations from the Amazon: Curiau and Pacoval. Exact tests for population differentiation revealed significant differences in allele frequency between populations only for the D1S80 and APOB loci. A statistically significant deviation from the Hardy-Weinberg equilibrium was observed only in the D1S80 locus of the Pacoval sample. A neighbor-joining tree was constructed based on DA genetic distances of allele frequencies in four Afro-Brazilian populations from the Amazon (Pacoval, Curiau, Trombetas, and Cametá), along with those from Congo, Cameroon, Brazilian Amerindians, and Europeans. This analysis revealed the usefulness of these Amp-FLPs for population studies -African and African-derived populations were closely grouped, and clearly separated from Amerindians and Europeans. Estimates of admixture components based on the gene identity method revealed the prevalence of the African component in both populations studied, amounting to 51% in Pacoval, and to 43% in Curiau. The Amerindian component was also important in both populations (37% in Pacoval, and 24% in Curiau). The European component reached 33% in Curiau.

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“…At present, at least 743 remnant quilombo communities have been identified in Brazil with most of them being located in the northeastern region of Brazil. In many of these communities genetic studies have shown several degrees of admixture with indigenous groups and European descendants (e.g., Arpini-Sampaio et al, 1999;Guerreiro et al, 1999).…”

Section: Introductionmentioning

confidence: 99%

CCR5D32 mutation in three Brazilian populations of predominantly Sub-Saharan African ancestry

et al. 2004

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This study reports the frequencies of the CCR5D32 mutation of the β-chemokine 5 gene and discusses the possible effects of past and recent gene flow in three quilombo remnants (Brazilians communities with anthropological African ancestry whose ancestors were escaped slaves): Rio das Rãs, Mocambo, and São Gonçalo in the northeastern region of Brazil. The CCR5D32 allele frequency of the Mocambo population was significantly higher (5.6%) than that found in the Rio das Rãs (1%) and São Gonçalo (0.9%) populations. These differences may reflect different proportions of parental populations in the founders individuals, a founder-effect and/or different histories of inter-ethnic contact. The frequency of the CCR5D32 allele in the Mocambo sample is similar to that found in those urban Brazilian populations which have a large amount of European genetic input, indicating a European contribution to the gene pool of this population and suggesting that, perhaps since its foundation, Mocambo has had a high level of admixture or experienced a founder-effect.

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Genetical-demographic data from two amazonian populations composed of descendants of african slaves: Pacoval and Curiau

Cited by 38 publications

References 4 publications

Afro-Derived Amazonian Populations: Inferring Continental Ancestry and Population Substructure

Afro-Derived Amazonian Populations: Inferring Continental Ancestry and Population Substructure

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

CCR5D32 mutation in three Brazilian populations of predominantly Sub-Saharan African ancestry

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