Pre-Columbian male ancestors for the American Continent, molecular Y-chromosome insight.

BAILLIET G; MUZZIO M; RAMALLO V; JURADO MEDINA LS; ALFARO EL; DIPIERRI JE; BRAVI CM

Genetic Diversity / Book 4

In Tech d.o.o.

Lugar: Rijeka; Año: 2012;

Pre-Columbian male ancestors for the American Continent, molecular Y-chromosome insight.  Bailliet G, Muzzio M, Ramallo V, Jurado Medina LS, Alfaro EL, Dipierri JE, Bravi CM  The study of SNP polymorphisms in the specific region of Y- Chromosome resulted in the construction of a consistent phylogeny and nomenclature (YCC 2002, Karafet et al., 2008). This phylogeny spanned in a tree of 20 mayor clades representing haplogrups, in which the accumulation of polymorphisms along the lineages has determined their diversification and configuration of sub-branches. The phylogeny seems to have a geographic distribution that follows the routes of dispersion of human populations. There is no doubt that Siberia was the main source of colonization to America, one of the last continents to be populated. Multidisciplinary evidence support the hypothesis that strong bottlenecks happened during this process, yet when it happened and how many migratory waves occurred is still debated. All present evidence about the Y-chromosomes in human populations of America indicates that Native American lineages were restricted to the two Y-chromosome haplogroups C and Q.  The C haplogroup, defined by RPS4Y and M216, has been described in Asia, Australo-Melanesia and North America (Bergen et al. 1999; Karafet et al., 1999, Capelli et al. 2001; Hammer et al. 2001;), and the lineages that acquired another mutation, M217, spread through central and eastern Asia and North America (Karafet et al., 1999;  Zegura et al. 2004). The North American C haplogroup lineage was characterized by the derived alleles for RPS4Y, M217 and P39 corresponding to sub-haplogroup C3b. Two samples from Wayu were the first South American C lineages identified (Zegura et al., 2004), and new evidence of presence C3 in South American was found in three Waorani and one Kichwa individuals, although P39 was absent (Geppert et al. 2011).   The Q haplogroup was defined by the M242 mutation (Seielstad et al., 2003). Currently, it has frequencies lower than 17%, with an average of 5%, in Asia (Seielstad et al., 2003), and of 18.8% in Siberia (Karafet et al., 2002). In North America they rise up to 47% (13.9% average) (Zegura et al., 2004; Bolnick et al., 2006), yet it is poorly represented in most South American populations (<6%) (Bortolini et al., 2003; Bailliet et al., 2009; Bisso-Machado et al., 2010). Recent publications showed that all analyzed chromosomes from the Q haplogroup had a derived state for the M242 and M346 polymorphisms, plus the ancestral state for M3, so they were assigned as Q1a3* para-haplogroup (Bailliet et al., 2009, Bisso-Machado et al., 2010). In South America, most native males carry a Y-chromosome lineage named Q1a3a sub-haplogroup (Karafet et al., 2008), which is characterized by a one base pair polymorphism, M3 (Underhill et al., 1996), and the derived states for M242 and M346. It was described very early in the study of Y lineages for America (Pena et al., 1995, Underhill et al., 1996), and it was found in all Native American populations from Alaska to the Magellan’s Strait, in average frequencies of at least 60% (Bianchi et al., 1998, Bortolini et al., 2003). This lineage was initially thought to be the only “founder” (Underhill et al, 1996), however it is nowadays considered “autochthonous” since posterior studies showed that M3 occurred either in America or in Siberia shortly before migrating (Lell et al, 2002). At moment, there are important amounts of information regarding samples analyzed for the C and Q haplogroups from many locations with a vast geographic distribution, so it is possible to analyze the peculiarities of the geographic distribution of male lineages and their diversity in America. Accordingly, we aim to review the available information of C and Q lineages from North and South America, in order to find these peculiarities and evidences of genetic differentiation.