Y-chromosome and Surname Analyses for Reconstructing Past Population Structures: The Sardinian Population as a Test Case

Abstract

Many anthropological, linguistic, genetic and genomic analyses have been carried out to evaluate the potential impact that evolutionary forces had in shaping the present-day Sardinian gene pool, the main outlier in the genetic landscape of Europe. However, due to the homogenizing effect of internal movements, which have intensified over the past fifty years, only partial information has been obtained about the main demographic events. To overcome this limitation, we analyzed the male-specific region of the Y chromosome in three population samples obtained by reallocating a large number of Sardinian subjects to the place of origin of their monophyletic surnames, which are paternally transmitted through generations in most of the populations, much like the Y chromosome. Three Y-chromosome founding lineages, G2-L91, I2-M26 and R1b-V88, were identified as strongly contributing to the definition of the outlying position of Sardinians in the European genetic context and marking a significant differentiation within the island. The present distribution of these lineages does not always mirror that detected in ancient DNAs. Our results show that the analysis of the Y-chromosome gene pool coupled with a sampling method based on the origin of the family name, is an efficient approach to unravelling past heterogeneity, often hidden by recent movements, in the gene pool of modern populations. Furthermore, the reconstruction and comparison of past genetic isolates represent a starting point to better assess the genetic information deriving from the increasing number of available ancient DNA samples.

High Coverage Mitogenomes and Y-Chromosomal Typing Reveal Ancient Lineages in the Modern-Day Székely Population in Romania

“…In Hungary, 16.74% of men carry this haplotype [21]. I2a-P37 and subgroups occur at high frequencies in Sardinia (38.9% [63]) and are also present at high frequency among Balkan populations [64]. The proportion of the I2a1a Y type in the Romanian population is 17.7% [64].…”

Characterization of the Y Chromosome in Newfoundland and Labrador: Evidence of a Founder Effect

“…15 Detailed studies of Y chromosome haplotypes have revealed male migration patterns throughout history and led to an understanding of the origins of current human populations. 16,17,18,19,20 These studies contributed to the development of a standardized Y-DNA phylogenetic tree maintained by the International Society of Genetic Genealogy (ISOGG). 21 European Y chromosomes are primarily comprised of the haplogroups E, G, I, J, N and R, with the R haplogroup comprising the majority of the Y chromosomes.…”

High Coverage Mitogenomes and Y-Chromosomal Typing Reveal Ancient Lineages in the Modern-day Székely Population in Romania

“…In Hungary, 16.74% of men carry this haplotype [14]. I2a-P37 and subgroups occur at high frequencies in Sardinia (38.9% [57]), and are also present at high frequency among Balkan populations [58]. The proportion of the I2a1a Y type in the Romanian population is 17.7%.…”