Heterogeneity of mitochondrial DNA haplotypes in Pre‐Columbian natives of the Amazon region

Abstract

We report the first study of mitochondrial DNA (mtDNA) sequencing from ancestral Amerindian populations of the South American continent. Sequencing of the D-loop region of mtDNA was carried out for bone fragments from 18 skeletons of Pre-Columbian Amerinidians. The skeletons were excavated in different archeological sites of the Brazilian Amazon region, with dating estimated at 500-4,000 years before the present. The sequencing of at least 354 bases permitted the identification of 13 haplotypes defined by variation of 26 nucleotide positions. Two haplotypes were shared by more than one sample, while 11 haplotypes were observed for a single sample. Seven haplotypes observed in 11 individuals (61% of the sample) belong to the four haplogroups described by Horai et al. (1993). Three samples that shared the transition C-->T in positions 16,223 and 16,278 formed a fifth haplogroup, which has been previously described in present-day Indian populations. Finally, four samples formed a heterogeneous group but each haplotype had at least one mutation typically detected in Asian or Mongoloid populations. Thus, although only haplotypes shared by Asian populations were detected, a wide haplotype variability was observed. If our sample is representative of Pre-Columbian South America, the percentage of haplotypes (39%) not belonging to the four haplogroups described by Horai is much greater than in contemporary indigenous populations. This permits us to suggest that, in addition to the postulated bottleneck effect during the migration from Asia to the Americas, the depopulation effect started by European colonization in the 16th century contributed to the reduction in genetic variability of Amerindians.

An mtDNA Analysis in Ancient Basque Populations: Implications for Haplogroup V as a Marker for a Major Paleolithic Expansion from Southwestern Europe

“…On the other hand, similar rates of success (80%-100%) have been found by other authors using the same method of analysis (restriction enzymes) (Stone and Stoneking 1993;Lalueza et al 1997;Parr et al 1996). However, when the analysis performed comprises the sequencing of the amplified fragment, the rate of success decreases to 55%-70% (Hagelberg and Clegg 1993;Oota et al 1995;Ribeiro-Dos-Santos et al 1996).…”

The peopling of South America and the trans-Andean gene flow of the first settlers

“…The origin of B2b3a (and B2b3a1, too) could be placed close to the Amazon River delta, as witnessed by its high frequency in the region (Fig. 4D) as well as the detection of a 4-ky-old sample from Pirabas (north of Pará state) carrying the HVS-I motif T16189C-T16217C-T16249C-A16312G-C16344T (Ribeiro-dos-Santos et al 1996). The subclade B2b3a2 arose in Brazil ∼3.9 kya (3.3-4.8 kya) and likely spread southward following the Atlantic as testified by the presence of a B2b3a2 member in Uruguay (Guarani) (Sans et al 2015) and Argentineans from Río de la Plata (Fig.…”

mtDNA Haplogroup X: An Ancient Link between Europe/Western Asia and North America?

“…An ancient arrival of haplogroup X in the Americas could be corroborated by the presence of haplogroup X in pre-Columbian human remains. Two studies on mtDNA variation in pre-Columbian samples have reported partial CR sequences that include the 16223T-and-16278T motif (Hauswirth et al 1994;Ribeiro-Dos-Santos et al 1996). However, in the absence of either more-complete CR sequence or RFLP data, it is not possible to definitively assign these pre-Columbian mtDNAs to haplogroup X.…”