Prehistoric migrations through the Mediterranean basin shaped Corsican Y-chromosome diversity

Julie Di Cristofaro (1) , Stéphane Mazières (1) , Audrey Tous (2) , Cornelia Di Gaetano , Alice Lin (3) , Paul Nebbia , Alberto Piazza , Roy King (4) , Peter Underhill (5) , Jacques Chiaroni (6)

1 ADES - Anthropologie bio-culturelle, Droit, Ethique et Santé
2 EFS - Alpes-Méditerranée - Etablissement Français du Sang - Alpes-Méditerranée
3 EHESS - École des hautes études en sciences sociales
4 Department of Psychiatry and Behavioral Sciences [Stanford]
5 Department of Genetics [Stanford]
6 UAABC - Anthropologie Bio-Culturelle

The rarity of human remains makes it difficult to apprehend the first settlements in Corsica. It is admitted that initial colonization could have occurred during the Mesolithic period when glaciations would have shortened the open water travel distance from the continent. Meso-lithic sites in Corsica show relatively short and irregular occupation, and suggest discontinu-ous settling of very mobile groups probably traveling by boat. Previous genetic studies on Corsican populations showed internal differentiation and a relatively poor genetic relationship with continental populations, despite intense historical contacts, however local Meso-lithic-based genetic inheritance has never been properly estimated. The aim of this study was to explore the Corsican genetic profile of Y-chromosomes in order to trace the genetic signatures back to the first migrations to Corsica. This study included 321 samples from men throughout Corsica; samples from Provence and Tuscany were added to the cohort. All samples were typed for 92 Y-SNPs, and Y-STRs were also analyzed. Results revealed highly differentiated haplogroup patterns among Corsican populations. Haplogroup G had the highest frequency in Corsica, mostly displaying a unique Y-STR profile. When compared with Provence and Tuscany, Corsican populations displayed limited genetic proximity. Cor-sican populations present a remarkable Y-chromosome genetic mixture. Although the Cor-sican Y-chromosome profile shows similarities with both Provence and to a lesser extent Tuscany, it mainly displays its own specificity. This study confirms the high level of genetic diversity in Corsican populations and backs genetic contributions from prehistoric migrations associated with the Mesolithic, Neolithic and Metal Age eras, rather than from historical movements to Corsica, respectively attested by frequencies and TMRCA of haplogroups G2a-L91 and G2a-P15, J2a-M241 and J2-DYS445 = 6, R1b-U152 and R1b-U106. These results suggest that marine routes to reach the Corsican coast in many different points may have led to such a genetic heterogeneity.

Mots clés: Y chromosomes; Neolithic period; Population genetics; Haplogroups; Mesolithic period; Paleogenetics; Italy; Islands

Domaines: Anthropologie biologique

Julie Di Cristofaro, Stéphane Mazières, Audrey Tous, Cornelia Di Gaetano, Alice Lin, et al.. Prehistoric migrations through the Mediterranean basin shaped Corsican Y-chromosome diversity. PLoS ONE, 2018, 13 (8), pp.e0200641. ⟨10.1371/journal.pone.0200641⟩. ⟨hal-01863090⟩