Biology subjects

Semino, O.

Publications and source records attributed to Semino, O..

7 recordsLinked to original sources

bioRxiv2026

LAYERED GENOMIC COMPOSITION AND LINGUISTIC CONTINUITY IN GRECIA SALENTINA

Grecia Salentina (GS) is the label assigned to a geographic area in Southern Italy where a Greek dialect has historically been spoken. The origins of this Greek-speaking community, whether dating from ancient or Medieval settlement, are a controversial and essentially unsolved issue. To evaluate which historical-linguistic scenario is best supported on genomic grounds, we used whole genome sequencing of 27 GS natives and 21 controls, embedding them in a 799 modern samples dataset in which Greece and Anatolia were evenly represented, an uncommon feature in the genomic literature on the area. We considered different aspects of the genetic structuring, at different spatial and temporal scales. Analyses also included 4021 ancient samples from the literature. All analyses pointed to the same conclusion: the GS genomic profile displays the same characteristic features of the rest of Southern Italy, with no definite evidence for a single source population from outside Italy. Correspondingly, we detected strong genetic connectivity among GS municipalities and between GS and the rest of Italy. Only a subset of our analyses suggested a slightly increased affinity of GS with Greece, or with the Anatolian peninsula. These results indicate that GS has been all but a genetically closed community, and that the Greek language did not act as a barrier to gene flow. By endorsing a ''transient mobility model'' we support the most recent linguistic hypothesis: the prolonged resilience of the Greek language in GS, maintained in situ and periodically rejuvenated through recurrent external inputs from the Greek and Byzantine worlds.

genetics↗

bioRxiv2023

Echoes from the last Green Sahara: whole genome analysis of Fulani, a key population to unveil the genetic evolutionary history of Africa

BackgroundThe Sahelian Fulani are the largest nomadic pastoral ethnic group. Their origins are still largely unknown and their Eurasian genetic component is usually explained by recent admixture events with northern African groups. However, it has also been proposed that Fulani may be the descendants of ancient groups settled in the Sahara during its last Green phase (12000-5000 BP), as also suggested by Y chromosome results. ResultsWe produced 23 high-coverage (30 x) whole genomes from Fulani individuals from 8 Sahelian countries, plus 17 samples from other African groups and 3 Europeans as controls, for a total of 43 new whole genome sequences. These data have been compared with 814 published modern whole genomes and analyzed together with relevant published ancient individuals (for a total of > 1800 samples). These analyses showed that the non-sub-Saharan genetic ancestry component of Fulani cannot be only explained by recent admixture events, but it could be shaped at least in part by older events by events more ancient than previously reported, possibly tracing its origin to the last Green Sahara. ConclusionsAccording to our results, Fulani may be the descendants of Saharan cattle herders settled in that area during the last Green Sahara. The exact ancestry composition of such ghost Saharan population(s) cannot be completely unveiled from modern genomes only, but the joint analysis with the available African ancient samples suggested a similarity between ancient Saharans and Late Neolithic Moroccans.

genetics↗

bioRxiv2022

Assessing temporal and geographic contacts across the Adriatic Sea through the analysis of genome-wide data from Southern Italy

Southern Italy was characterised by a complex prehistory that started with different Palaeolithic cultures, later followed by the Neolithic transition and the demic dispersal from the Pontic-Caspian Steppe during the Bronze Age. Archaeological and historical evidence points to demic and cultural influences between Southern Italians and the Balkans, starting with the initial Palaeolithic occupation until historical and modern times. To shed light on the dynamics of these contacts, we analysed a genome-wide SNP dataset of more than 700 individuals from the South Mediterranean area (102 from Southern Italy), combined with ancient DNA from neighbouring areas. Our findings revealed high affinities of South-Eastern Italians with modern Eastern Peloponnesians, and a closer affinity of ancient Greek genomes with those from specific regions of South Italy than modern Greek genomes. The higher similarity could be associated with the presence of a Bronze Age component ultimately originating from the Caucasus and characterised by high frequencies of Iranian and Anatolian Neolithic ancestries. Furthermore, to reveal possible signals of natural selection, we looked for extremely differentiated allele frequencies among Northern and Southern Italy, uncovering putatively adapted SNPs in genes involved in alcohol metabolism, nevi features and immunological traits, such as ALDH2, NID1 and CBLB.

genomics↗

bioRxiv2020

Archaeogenomic Distinctiveness of the Isthmo-Colombian Area

The recently enriched genomic history of Indigenous groups in the Americas is still meagre concerning continental Central America. Here, we report ten pre-Hispanic (plus two early colonial) genomes and 84 genome-wide profiles from seven groups presently living in Panama. Our analyses reveal that pre-Hispanic demographic changes and isolation events contributed to create the extensive genetic structure currently seen in the area, which is also characterized by a distinctive Isthmo-Colombian Indigenous component. This component drives these populations on a specific variability axis and derives from the local admixture of different ancestries of northern North American origin(s). Two of these ancestries were differentially associated to Pleistocene Indigenous groups that also moved into South America leaving heterogenous footprints. An additional Pleistocene ancestry was brought by UPopI, a still unsampled population that remained restricted to the Isthmian area, expanded locally during the early Holocene, and left genomic traces up to the present.

genomics↗

bioRxiv2019

Genome-wide analysis of Corsican population reveals a close affinity with Northern and Central Italy

Despite being the fourth largest island in the Mediterranean basin, the genetic variation of Corsica has not been explored as exhaustively as Sardinia, which is situated only 11 km South. However, it is likely that the populations of the two islands shared, at least in part, similar demographic histories. Moreover, the relative small size of the Corsica may have caused genetic isolation, which, in turn, might be relevant under medical and translational perspectives. Here we analysed genome wide data of 16 Corsicans, and integrated with newly (33 individuals) and previously generated samples from West Eurasia and North Africa. Allele frequency, haplotype-based, and ancient genome analyses suggest that although Sardinia and Corsica may have witnessed similar isolation and migration events, the latter is genetically closer to populations from continental Europe, such as Northern and Central Italians.

genomics↗

bioRxiv2019

The genomic impact of European colonization of the Americas

The human genetic diversity of the Americas has been shaped by several events of gene flow that have continued since the Colonial Era and the Atlantic slave trade. Moreover, multiple waves of migration followed by local admixture occurred in the last two centuries, the impact of which has been largely unexplored.\n\nHere we compiled a genome-wide dataset of [~]12,000 individuals from twelve American countries and [~]6,000 individuals from worldwide populations and applied haplotype-based methods to investigate how historical movements from outside the New World affected i) the genetic structure, ii) the admixture profile, iii) the demographic history and iv) sex-biased gene-flow dynamics, of the Americas.\n\nWe revealed a high degree of complexity underlying the genetic contribution of European and African populations in North and South America, from both geographic and temporal perspectives, identifying previously unreported sources related to Italy, the Middle East and to specific regions of Africa.

genomics↗

bioRxiv2018

Population structure of modern-day Italians reveals patterns of ancient and archaic ancestries in Southern Europe

European populations display low genetic diversity as the result of long term blending of the small number of ancient founding ancestries. However it is still unclear how the combination of ancient ancestries related to early European foragers, Neolithic farmers and Bronze Age nomadic pastoralists can fully explain genetic variation across Europe. Populations in natural crossroads like the Italian peninsula are expected to recapitulate the overall continental diversity, but to date have been systematically understudied. Here we characterised the ancestry profiles of modern-day Italian populations using a genome-wide dataset representative of modern and ancient samples from across Italy, Europe and the rest of the world. Italian genomes captured several ancient signatures, including a non-steppe related substantial ancestry contribution ultimately from the Caucasus. Differences in ancestry composition as the result of migration and admixture generated in Italy the largest degree of population structure detected so far in the continent and shaped the amount of Neanderthal DNA present in modern-day populations.\n\nOne sentence summaryAncient and historical admixture events shaped the genetic structure of modern-day Italians, the ancestry profile of Southern European populations and the continental distribution of Neanderthal legacy.

genomics↗