Data from: Traces of Medieval migrations in a socially-stratified population from Northern Italy. Evidence from uniparental markers and deep-rooted pedigrees.

Social and cultural factors had a critical role in determining the genetic structure of Europe. Therefore, socially stratified populations may help to focus on specific episodes of European demographic history. In this study, we use uniparental markers to analyse the genetic structure of Partecipanza in San Giovanni in Persiceto (Northern Italy), a peculiar institution whose origins date back to the Middle Ages and whose members form the patrilineal descent of a group of founder families. From a maternal point of view (mtDNA), Partecipanza is genetically homogeneous with the rest of the population. However, we observed a significant differentiation for Y-chromosomes. In addition, by comparing 17 Y-STR profiles with deep-rooted paternal pedigrees, we estimated a Y-STR mutation rate equal to 3.90 * 10−3 mutations per STR per generation and an average generation duration time of 33.38 years. When we used these values for tentative dating, we estimated 1300-600 years ago for the origins of the Partecipanza. These results, together with a peculiar Y-chromosomal composition and historical evidence, suggest that Germanic populations (Lombards in particular) settled in the area during the Migration Period (400–800 AD, approximately) and may have had an important role in the foundation of this community

Detecting genetic isolation in human populations: a study of European language minorities.

The identification of isolation signatures is fundamental to better understand the genetic structure of human populations and to test the relations between cultural factors and genetic variation. However, with current approaches, it is not possible to distinguish between the consequences of long-term isolation and the effects of reduced sample size, selection and differential gene flow. To overcome these limitations, we have integrated the analysis of classical genetic diversity measures with a bayesian method to estimate gene flow and have carried out simulations based on the coalescent. Combining these approaches, we first tested whether the relatively short history of cultural and geographical isolation of four "linguistic islands" of the Eastern Alps (Lessinia, Sauris, Sappada and Timau) had left detectable signatures in their genetic structure. We then compared our findings to previous studies of European population isolates. Finally, we explored the importance of demographic and cultural factors in shaping genetic diversity among the groups under study. A combination of small initial effective size and continued genetic isolation from surrounding populations seems to provide a coherent explanation for the diversity observed among Sauris, Sappada and Timau, which was found to be substantially greater than in other groups of European isolated populations. Simulations of micro-evolutionary scenarios indicate that ethnicity might have been important in increasing genetic diversity among these culturally related and spatially close populations

The impact of forensic genetics on the management of sexual assault victims: A multicentre GE.F.I project

13noWe conducted a retrospective study to analyse the ways in which sexual abuse was handled by the Italian forensic geneticists in order to delineate common strategies in the management of the collected biological samples. In particular, the results of laboratory analyses were compared with the patients’ reports and the outcome of their medical examination, as recorded on standard evidence collection documents. The purpose of this study is identifying which factors could influence the congruence between what was reported and the typing of male genetic profiles. The project was proposed at the Italian Society of Forensic Genetics and 10 laboratories have joined the study filling in a questionnaire. We analysed 102 cases that occurred between 2006 and 2017. The analysis of the data here presented highlights that the ability to ascertain the presence of male biological material in the collected evidence is not a technical problem for forensic genetics laboratories but it seems to be influenced by other factors, such as how much time elapsed before being taken into care, actions or other relevant events that have occurred between the assault and the medical examination, and the characterisation of the evidence.reservedmixedGino S.; Bo M.; Ricciardelli R.; Alu M.; Boschi I.; Carnevali E.; Fabbri M.; Fattorini P.; Piccinini A.; Previdere C.; Verzeletti A.; Tozzo P.; Caenazzo L.Gino, S.; Bo, M.; Ricciardelli, R.; Alu, M.; Boschi, I.; Carnevali, E.; Fabbri, M.; Fattorini, P.; Piccinini, A.; Previdere, C.; Verzeletti, A.; Tozzo, P.; Caenazzo, L

An Ancient Mediterranean Melting Pot: Investigating the Uniparental Genetic Structure and Population History of Sicily and Southern Italy

<div><p>Due to their strategic geographic location between three different continents, Sicily and Southern Italy have long represented a major Mediterranean crossroad where different peoples and cultures came together over time. However, its multi-layered history of migration pathways and cultural exchanges, has made the reconstruction of its genetic history and population structure extremely controversial and widely debated. To address this debate, we surveyed the genetic variability of 326 accurately selected individuals from 8 different provinces of Sicily and Southern Italy, through a comprehensive evaluation of both Y-chromosome and mtDNA genomes. The main goal was to investigate the structuring of maternal and paternal genetic pools within Sicily and Southern Italy, and to examine their degrees of interaction with other Mediterranean populations. Our findings show high levels of within-population variability, coupled with the lack of significant genetic sub-structures both within Sicily, as well as between Sicily and Southern Italy. When Sicilian and Southern Italian populations were contextualized within the Euro-Mediterranean genetic space, we observed different historical dynamics for maternal and paternal inheritances. Y-chromosome results highlight a significant genetic differentiation between the North-Western and South-Eastern part of the Mediterranean, the Italian Peninsula occupying an intermediate position therein. In particular, Sicily and Southern Italy reveal a shared paternal genetic background with the Balkan Peninsula and the time estimates of main Y-chromosome lineages signal paternal genetic traces of Neolithic and post-Neolithic migration events. On the contrary, despite showing some correspondence with its paternal counterpart, mtDNA reveals a substantially homogeneous genetic landscape, which may reflect older population events or different demographic dynamics between males and females. Overall, both uniparental genetic structures and TMRCA estimates confirm the role of Sicily and Southern Italy as an ancient Mediterranean melting pot for genes and cultures.</p></div

Y-STR haplotypes and haplogroups in Partecipanza and S. Giovanni in Persiceto samples

Y-STR haplotypes and haplogroups in Partecipanza and S. Giovanni in Persiceto sample

Spatial Principal Component Analysis (sPCA) based on Y-chromosome haplogroups frequencies.

<p>The first two global components, sPC1 (a) and sPC2 (b), are depicted. Positive values are represented by black squares; negative values are represented by white squares; the size of the square is proportional to the absolute value of sPC scores.</p

Discriminant Analysis of Principal Components (DAPC) based on Y-chromosome sPC1-identified structure.

<p>The barplot represents DAPC-based posterior membership probabilities for each of the considered populations to belong at each of the two sPC1-identified groups (white = South-Eastern Mediterranean; black = North-Western Mediterranean). Population codes as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0096074#pone.0096074.s004" target="_blank">Table S1</a>.</p

Admixture-like barplots for Y-chromosome (a) and mtDNA (b).

<p>The barplots represent DAPC-based posterior membership probabilities for each of the considered populations and for each inferred cluster (<i>mclust</i> algorithm). The affiliation of each population to a given cluster and its corresponding colour code are represented by letters (within coloured squares) on the top of each bar. Labels: NAFR: North-Africa, LEV: Levant, BALK: Balkans, SSI: Sicily and South-Italy, NCI: North-Central Italy, IBE: Iberian Peninsula, GER: Germany.</p