Each population isolate has a unique demographic history in terms of initial size , time since foundation and growth rate. These factors can shape their genetic makeup both at the individual and population level. However, is it possible to identify patterns relating genomic diversity and demographic history? To answer this question we analyzed approximately 90,000 autosomal ancestry informative markers (AIMs) as part of the Genochip (National Geographic Society, Washington, DC & Family Tree DNA, Houston, Texas, USA) in eight Italian populations, all subject to geographic and/or cultural isolation factors. Four were from Sardinia (old and large isolates) and as many from the eastern Alps (young and small isolates). The same panel of AIMs was analyze d in literature data relative to both open and isolated European groups, for a total of 24 populations. Alpine isolates (German-speaking linguistic islands of Sappada, Sauris and Timau) showed stronger signals of genetic isolation [i.e. frequency and size of Runs of Homozygosity, LD decay and intra-group distributions of Identity by State (IBS)] than older and larger groups (Sardinians, Basques and Orcadians). Rather unexpectedly, the ADMIXTURE and PCA analyses, as well as the comparison of intra-group IBS distributions, highlighted a noticeable genetic heterogeneity within Sappada, Sauris and Timau, likely due to relatively recent admixture events. This pattern, undetected in any other population sample, is at odds with the conventional view of a substantial genetic homogeneity within population isolates. Significance and implications of our results are discussed in relation to both micro-evolutionary aspects and bio-medical applications.
THE EMERGING COMPLEXITY OF GENOMIC ARCHITECTURE IN HUMAN POPULATION ISOLATES / Anagnostou, Paolo; Dominici, Valentina; BATTAGGIA BURATTINI, Cinzia; Pagani, L; Vilar, Mg; Wells, Rs; Pettener, D; Luiselli, D; Boattini, A; Francalacci, P; Calò, Cm; DESTRO-BISOL, Giovanni; The, Genographic Consortium. - (2015). (Intervento presentato al convegno Towards a Next - Generation Anthropology: challenges & synergies tenutosi a Bologna nel 3-5 Settembre 2015).
THE EMERGING COMPLEXITY OF GENOMIC ARCHITECTURE IN HUMAN POPULATION ISOLATES
ANAGNOSTOU, PAOLO;DOMINICI, VALENTINA;BATTAGGIA BURATTINI, Cinzia;DESTRO-BISOL, Giovanni;
2015
Abstract
Each population isolate has a unique demographic history in terms of initial size , time since foundation and growth rate. These factors can shape their genetic makeup both at the individual and population level. However, is it possible to identify patterns relating genomic diversity and demographic history? To answer this question we analyzed approximately 90,000 autosomal ancestry informative markers (AIMs) as part of the Genochip (National Geographic Society, Washington, DC & Family Tree DNA, Houston, Texas, USA) in eight Italian populations, all subject to geographic and/or cultural isolation factors. Four were from Sardinia (old and large isolates) and as many from the eastern Alps (young and small isolates). The same panel of AIMs was analyze d in literature data relative to both open and isolated European groups, for a total of 24 populations. Alpine isolates (German-speaking linguistic islands of Sappada, Sauris and Timau) showed stronger signals of genetic isolation [i.e. frequency and size of Runs of Homozygosity, LD decay and intra-group distributions of Identity by State (IBS)] than older and larger groups (Sardinians, Basques and Orcadians). Rather unexpectedly, the ADMIXTURE and PCA analyses, as well as the comparison of intra-group IBS distributions, highlighted a noticeable genetic heterogeneity within Sappada, Sauris and Timau, likely due to relatively recent admixture events. This pattern, undetected in any other population sample, is at odds with the conventional view of a substantial genetic homogeneity within population isolates. Significance and implications of our results are discussed in relation to both micro-evolutionary aspects and bio-medical applications.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
