RESUMO
BACKGROUND: Previous investigations of French Guiana Amerindians performed by this group included blood group and protein genetic markers, mitochondrial DNA and Y-chromosome investigations. Molecular autosomal data and more extensive Y-chromosome determinations were lacking. SUBJECTS AND METHODS: The genetic variability of 15 autosome (ASTRs) and 17 Y-chromosome (YSTRs) microsatellite loci was studied in four French Guiana (Emerillon, Palikur, Wayampi, Kali'na) and one Brazilian (Apalai) Amerindian populations. A sixth group, the Peruvian Matsiguenga of the Maipurean linguistic family, was included in the data analysis since they could provide information about the past migration of people from that linguistic stock into northeastern Amazonia. RESULTS: Marked ASTR and YSTR variability was found, with 96% of the YSTR haplotypes being found in one population only. There was excellent agreement between the present and previous autosomal or uniparental results. Multidimensional scaling based on F(ST) genetic distances and population structure analysis revealed heterogeneity in gene distribution, with a clear difference between the Matsiguenga and Emerillon and the other groups. In the latter, Wilcoxon sign-rank test between observed and expected heterozygosity and the mode of allele frequency distribution revealed clues of a significant past genetic bottleneck. The Wayampi stand genetically closer to the Apalai, Palikur and Kali'na when examined for the autosome but not the Y-chromosome panel of markers, suggesting preferential female gene flow. CONCLUSION: The new data provided additional important information about the biological history of people from a remote South American region, indicating how gene diversity analyses can be used to increase understanding of human microevolutionary processes.
Assuntos
Cromossomos Humanos Y/genética , Cromossomos Humanos/genética , Indígenas Sul-Americanos/genética , Repetições de Microssatélites , Brasil , Demografia , Feminino , Guiana Francesa , Fluxo Gênico , Frequência do Gene , Marcadores Genéticos , Variação Genética , Geografia , Haplótipos , Humanos , Masculino , Linhagem , Peru , Reação em Cadeia da Polimerase , Polimorfismo Genético , Estatísticas não ParamétricasRESUMO
The Hmong Diaspora is one of the widest modern human migrations. Mainly localised in South-East Asia, the United States of America, and metropolitan France, a small community has also settled the Amazonian forest of French Guiana. We have biologically analysed 62 individuals of this unique Guianese population through three complementary genetic markers: mitochondrial DNA (HVS-I/II and coding region SNPs), Y-chromosome (SNPs and STRs), and the Gm allotypic system. All genetic systems showed a high conservation of the Asian gene pool (Asian ancestry: mtDNA=100.0%; NRY=99.1%; Gm=96.6%), without a trace of founder effect. When compared across various Asian populations, the highest correlations were observed with Hmong-Mien groups still living in South-East Asia (Fst<0.05; P-value<0.05). Despite a long history punctuated by exodus, the French Guianese Hmong have maintained their original genetic diversity.
Assuntos
Povo Asiático/genética , Sudeste Asiático , Cromossomos Humanos X/genética , DNA Mitocondrial/genética , Interpretação Estatística de Dados , Etnicidade/genética , Guiana Francesa , Frequência do Gene , Pool Gênico , Variação Genética , Haplótipos , Migração Humana , Humanos , Imunoglobulina G/genética , Imunoglobulina G/imunologia , Polimorfismo de Nucleotídeo Único , População , Sequências de Repetição em TandemRESUMO
Hearing troubles were found to be very frequent among inhabitants of French origin in a small Caribbean island. Segregation analysis of hearing loss was performed in 165 complete nuclear families and revealed that familial aggregation could be entirely explained by a single recessive gene with high frequency (0.40). Homozygous individuals for this gene would probably be more suscepticle to ototoxic agents than other individuals. High frequency of this gene may be due to a founder effect (AU)
Assuntos
Humanos , Masculino , Feminino , Surdez , Genes Recessivos , Audiometria , Consanguinidade , Frequência do Gene , Homozigoto , Modelos Genéticos , Índias OcidentaisRESUMO
This study examines the relationships between blood pressure, prevalence of hypertension, and the degree of black African admixture in the population of the Caribbean Island of La Desirade which is homogenous with respect to the environmental factors and for which the socioeconomical stratification does not match racial origin. The degree of admixture was estimated by using both genealogical information and genetic markers. Blood pressure was repeatedly measured using an automatic sphygmomanometer. After adjustment for age, sex, ponderal index, Na/K urinary ratio, and clinical alcoholism, blood pressure and prevalence of hypertension were found to be significantly higher for the individuals having the largest proportion of genes of black origin. Identical results were obtained when either genetic markers or genealogical information were used as an individual-estimator of admixture. (AU)
Assuntos
Humanos , Adolescente , Adulto , Pessoa de Meia-Idade , Idoso , Masculino , Feminino , Pressão Arterial , Hipertensão/epidemiologia , /genética , Sistema ABO de Grupos Sanguíneos/genética , Antígenos de Grupos Sanguíneos/genética , /genética , Frequência do Gene , Hemoglobinas/genética , Antígenos HLA/genética , Alótipos Gm de Imunoglobulina/genética , Antígenos do Grupo Sanguíneo de Lewis/genética , Sistema do Grupo Sanguíneo Rh-Hr/genética , Índias OcidentaisRESUMO
Our recent segregation analysis, carried out on 27 large pedigrees from a Caribbean island (Desirade), has shown the presence of recessive major gene(s) controlling susceptibility to leprosy per se and nonlepromatous leprosy, respectively. Linkage analysis was performed between each of these two detected genes and each of five markers typed in the Desirade population: HLA, ABO, Rhesus, Gm and Km. No positive significant lod score was observed. However, for leprosy per se close linkage was excluded with Rhesus and Gm (and also with ABO and HLA, considering a lower value for the frequency of the gene controlling susceptibility to leprosy per se). The highest lod score, although not significant, was obtained between the gene for nonlepromatous leprosy and ABO. Our overall results, joined with previous studies and experimental data, suggest that the gene controlling susceptibility to leprosy per se and that controlling susceptibility to nonlepromatous leprosy might be different, acting at successive stages of the immune response to infection with Mycobacterium leprae. (AU)