Ancestry informative markers in Amerindians from Brazilian Amazon

Ancestry informative markers (AIMs) are genetic loci with large frequency differences between the major ethnic groups and are very useful in admixture estimation. However, their frequencies are poorly known within South American indigenous populations, making it difficult to use them in admixture studies with Latin American populations, such as the trihybrid Brazilian population. To minimize this problem, the frequencies of the AIMs FY-null RB2300, LPL, AT3-1/1), Sb19.3, APO, and PV92 were determined via PCR and PCR-RFLP in four tribes from Brazilian Amazon (Tikuna, Kashinawa, Baniwa, and Kanamari), to evaluate their potential for discriminating indigenous populations from Europeans and Africans, as well as discriminating each tribe from the others. Although capable of differentiating tribes, as evidenced by the exact test of population differentiation, a neighbor-joining tree suggests that the AIMs are useless in obtaining reliable reconstructions of the biological relationships and evolutionary history that characterize the villages and tribes studied. The mean allele frequencies from these AIMs were very similar to those observed for North American natives. They discriminated Amerindians from Africans, but not from Europeans. On the other hand, the neighbor-joining dendrogram separated Africans and Europeans from Amerindians with a high statistical support (bootstrap = 0.989). The relatively low diversity (GST = 0.042) among North American natives and Amerindians from Brazilian Amazon agrees with the lack of intra-ethnic variation previously reported for these markers. Despite genetic drift effects, the mean allelic frequencies herein presented could be used as Amerindian parental frequencies in admixture estimates in urban Brazilian populations

Y-STR diversity and ethnic admixture in White and Mulatto Brazilian population samples

We investigated 50 Mulatto and 120 White Brazilians for the Y-chromosome short tandem repeat (Y-STR) markers (DYS19, DYS390, DYS391, DYS392 and DYS393) and found 79 different haplotypes in the White and 35 in the Mulatto sample. Admixture estimates based on allele frequencies showed that the admixture of the white sample was 89% European, 6% African and 5% Amerindian while the Mulatto sample was 93% European and 7% African. Results were consistent with historical records of the directional mating between European males and Amerindian or African females

Y-STR diversity and ethnic admixture in White and Mulatto Brazilian population samples Short Communicaton

Abstract We investigated 50 Mulatto and 120 White Brazilians for the Y-chromosome short tandem repeat (Y-STR) markers (DYS19, DYS390, DYS391, DYS392 and DYS393) and found 79 different haplotypes in the White and 35 in the Mulatto sample. Admixture estimates based on allele frequencies showed that the admixture of the white sample was 89% European, 6% African and 5% Amerindian while the Mulatto sample was 93% European and 7% African. Results were consistent with historical records of the directional mating between European males and Amerindian or African females. The Brazilian population is a result of interethnic crosses of Europeans, Africans and Amerindians, and is one of the most heterogeneous populations in the world. When the first European colonizers arrived (1500 AD), 1-5 million Amerindians already lived in the region that now is known as Brazil (Salzano and Callegari-Jacques, 1988). Before 1820, European colonization was almost exclusively composed of Portuguese while between 1820 and 1975 the great majority of immigrants were from Portugal and Italy, followed by a small number by people from Spain, Germany, Syria and Japan . Between the 16 th and 19th centuries approximately 3.5 million Africans were brought as slaves to Brazil, coming mainly from West, West-Central and Southeast Africa Although the classification of races is wrong from genetic standpoint We investigated 170 healthy, unrelated, individuals seeking paternity investigation at the Ribeirão Preto University Hospital, in the city of Ribeirão Preto, São Paulo state, Southeastern Brazil. The race of the individuals in the sample was determined based on their biomedical records, 120 individuals being White and 50 Mulatto, from Ribeirão Preto and the surrounding towns. We assessed the Y-STR loci DYS19, DYS390, DYS391, DYS392 and DYS393 Allele and haplotype frequencies were estimated by the gene counting method and gene and haplotype diversities calculated using the ARLEQUIN software version 2.00

Flow Separation in Falling Liquid Films

BACKGROUND: Neuromyelitis optica (NMO) is considered relatively more common in non-Whites, whereas multiple sclerosis (MS) presents a high prevalence rate, particularly in Whites from Western countries populations. However, no study has used ancestry informative markers (AIMs) to estimate the genetic ancestry contribution to NMO patients. METHODS: Twelve AIMs were selected based on the large allele frequency differences among European, African, and Amerindian populations, in order to investigate the genetic contribution of each ancestral group in 236 patients with MS and NMO, diagnosed using the McDonald and Wingerchuck criteria, respectively. All 128 MS patients were recruited at the Faculty of Medicine of Ribeirão Preto (MS-RP), Southeastern Brazil, as well as 108 healthy bone marrow donors considered as healthy controls. A total of 108 NMO patients were recruited from five Neurology centers from different Brazilian regions, including Ribeirão Preto (NMO-RP). PRINCIPAL FINDINGS: European ancestry contribution was higher in MS-RP than in NMO-RP (78.5% vs. 68.7%) patients. In contrast, African ancestry estimates were higher in NMO-RP than in MS-RP (20.5% vs. 12.5%) patients. Moreover, principal component analyses showed that groups of NMO patients from different Brazilian regions were clustered close to the European ancestral population. CONCLUSIONS: Our findings demonstrate that European genetic contribution predominates in NMO and MS patients from Brazil

Information of ancestry informative markers (AIMs) set for ancestral populations, multiple sclerosis (MS) and neuromyelitis optica (NMO) patients.

<p>(A) The panel of 12 ancestry informative markers (AIMs) for Africans (green), Europeans (red) and Amerindians (blue) were sufficient for an adequate discrimination among ancestral populations. (B) Principal components analysis (PCA) for NMO [Southeastern: Ribeirão Preto (NMO-RP), São Paulo (NMO-SP) and Belo Horizonte (NMO-BH); Central:-Goiânia (NMO-GO), and Northeastern: (Recife-Pernambuco (NMO-PE)] and MS patients from Ribeirão Preto (MS-RP) and control individuals from Ribeirão Preto (CTRL-RP) together with ancestral populations [Africans (green), Europeans (red) and Amerindians (blue)], showing that they clustered closer to Europeans than to Africans and Amerindians.</p

African ancestry indexes (AAI) distribution for ancestral populations, multiple sclerosis (MS) and neuromyelitis optica (NMO) patients.

<p>Distribution of African ancestry Index (AAI) for Africans (AFR-green), Amerindians (AMZ-blue) and Europeans (EUR-red) in NMO patients from several Brazilian regions [Southeastern: Ribeirão Preto (NMO-RP), São Paulo (NMO-SP) and Belo Horizonte (NMO-BH); Central:-Goiânia (NMO-GO), and Northeastern: (Recife-Pernambuco (NMO-PE)]; in MS patients from Ribeirão Preto (MS-RP); and in healthy controls from Ribeirão Preto (CTRL-RP).</p

AIMs frequencies observed in MS and NMO patients and healthy controls from Ribeirao Preto (RP), and in Africans (AFR), Europeans (EUR) and Amerindians (AMZ).

<p>Significant differences (δ > 0.30) between ancestral populations are underlined in the last columns. European, African and Amerindian ancestry contributions and respective R² values are shown at the bottom of the Table.</p>a<p>Ancestry informative marker *1 alleles with their reference sequence number from database of National Center for Biotechnological Information (dbSNP/NCBI).</p>b<p>Single nucleotide polymorphism (SNP), insertion/deletion (Indel), and <i>Alu</i> insertion (Alu) polymorphism / allele that characterizes the *1 allele.</p>c<p>Chromosomal location of each AIM.</p

Demographic, clinical and laboratory findings of neuromyelitis optica (NMO) and multiple sclerosis (MS) Brazilian patients.

<p>Demographic, clinical and laboratory findings of neuromyelitis optica (NMO) and multiple sclerosis (MS) Brazilian patients.</p