Biology subjects

Torroni, A.

Publications and source records attributed to Torroni, A..

8 recordsLinked to original sources

bioRxiv2026

From prehistory to present-day: How isolation shaped the distinct genomic makeup of Italian Alpine valleys

Historically, the eastern Italian Alps have provided crucial geographic corridors for cultural and genetic exchange between the Mediterranean region and Central and Northern Europe. Although recent archaeogenomic data suggest a strong regional persistence of Anatolian Neolithic ancestry followed by the arrival of Yamnaya-related components during the Bronze Age, the genomic landscape of modern Alpine populations remains largely unmapped. In this study, we verified the persistence of these signals in the present-day Rendena and Ledro Valleys by integrating novel complete mitochondrial genomes (N=185) and genome-wide SNP data (N=96), the latter combined with a novel Italian genomic dataset (N=139). Our findings show that the Rendena and Ledro populations form a distinct "modern Alpine" genomic group, which retains a significant proportion of early European Neolithic ancestry, aligning with ancient eastern Italian Alpine individuals and modern Sardinians. More recently, geographic isolation and localized genetic drift appear to have shaped the two valleys differently. Demographic reconstructions reveal asynchronous population declines over the past two millennia, followed by a sharp, synchronized bottleneck 200-300 years ago, which coincided with historical plague outbreaks. Remarkably, this structured drift persisted at an extremely fine microgeographic scale within the valleys, resulting in internal genetic subclusters that directly correlate with local topography. This micro-differentiation was likely maintained by steep geographic barriers and/or local endogamous practices. This study ultimately underscores how geographic barriers and isolation can preserve ancient genomic components and shape highly localized genetic structures over centuries even to the modern day.

evolutionary biology↗

bioRxiv2026

DNA Traces on the Shroud of Turin: Metagenomics of the 1978 Official Sample Collection

This research provides original insights into the diversity of DNA extracted from samples collected in 1978 from the Turin Shroud, revealing its biological complexity through rigorous DNA and metagenomic analyses. Our findings highlight its preservation conditions and environmental interactions, offering valuable perspectives into the identified genetic variants, which originated from multiple biological sources. Several human mitochondrial DNA (mtDNA) lineages were identified, including K1a1b1a, which matches the 1978 official collectors mitogenome, H2a2 (i.e. the lineage of the mtDNA reference sequence rRCS), H1b, which is common in Western Eurasia, and H33, which is prevalent in the Near East and frequent among the Druze. Moreover, the reconstructed microbiome of the Shroud reveals a rich tapestry of multiple microbes commonly found on the human epidermis, as well as archaeal communities adapted to high salinity, and fungi including molds. This is indicative of the Shrouds preservation conditions over the centuries. Additionally, the presence of abundant Mediterranean endemic red coral, various cultivated plants (e.g. carrot, wheat, corn, bananas, and peanuts) and domesticated animals (e.g. cattle, pigs, chickens, dogs, and cats) provide a fascinating glimpse into the diverse biological sources of the contaminants that have accumulated on the Turin Shroud over time. Finally, radiocarbon dating of two distinct threads collected from the reliquary provides evidence of their use to repair the Shroud in the years 1534 and 1694 of the Common Era (CE). Significance statementAn in-depth metagenomic analysis was conducted on several linen strands collected from different areas of the body image of the Man of the Shroud during the official sampling in 1978. Our analyses revealed several human mtDNA lineages, including one common in Western Eurasia and another prevalent in the Near East. Additionally, the diversity of animal and plant species identified details the significant environmental contamination of the Shroud that likely occurred in recent centuries, particularly following the voyages of Marco Polo and Christopher Columbus. Radiocarbon dating of two distinct textile residuals from the Shrouds reliquary indicated a time range between 1451 and 1800 CE, overlapping with the period of its repair interventions.

genomics↗

bioRxiv2022

Pangenomics provides insights into the role of synanthropy in barn swallow evolution

Insights into the evolution of non-model organisms are often limited by the lack of reference genomes. As part of the Vertebrate Genomes Project, we present a new reference genome and a pangenome produced with High-Fidelity long reads for the barn swallow Hirundo rustica. We then generated a reference-free multialignment with other bird genomes to identify genes under selection. Conservation analyses pointed at genes enriched for transcriptional regulation and neurodevelopment. The most conserved gene is CAMK2N2, with a potential role in fear memory formation. In addition, using all publicly available data, we generated a comprehensive catalogue of genetic markers. Genome-wide linkage disequilibrium scans identified potential selection signatures at multiple loci. The top candidate region comprises several genes and includes BDNF, a gene involved in stress response, fear memory formation, and tameness. We propose that the strict association with humans in this species is linked with the evolution of pathways typically under selection in domesticated taxa.

genomics↗

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↗

bioRxiv2021

Projecting ancient ancestry in modern-day Arabians and Iranians: a key role of the past exposed Arabo-Persian Gulf on human migrations

Arabian Peninsula is strategic for investigations centred on the structuring of the modern human population in the three main groups, in the awake of the out-of-Africa migration. Despite the poor climatic conditions for recovery of ancient DNA human evidence in Arabia, the availability of genomic data from neighbouring ancient specimens and of informative statistical tools allow better modelling the ancestry of these populations. We applied this approach to a dataset of 741,000 variants screened in 291 Arabians and 78 Iranians, and obtained insightful evidence. The west-east axis was a strong forcer of population structure in the Peninsula, and, more importantly, there were clear continuums throughout time linking west Arabia with Levant, and east Arabia with Iran and Caucasus. East Arabians also displayed the highest levels of the basal Eurasian lineage of all tested modern-day populations, a signal that was maintained even after correcting for possible bias due to recent sub-Saharan African input in their genomes. Not surprisingly, east Arabians were also the ones with higher similarity with Iberomaurusians, who were so far the best proxy for the basal Eurasians amongst the known ancient specimens. The basal Eurasian lineage is the signature of ancient non-Africans that diverged from the common European-East Asian pool before 50 thousand years ago, and before the later interbred with Neanderthals. Our results are strong evidence to include the exposed basin of the Arabo-Persian Gulf as possible home of basal Eurasians, to be investigated further on namely by searching ancient Arabian human specimens.

genetics↗

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

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↗