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Montinaro, F.

Publications and source records attributed to Montinaro, F..

At least 19 recordsLinked to original sources

A segmental duplication-mediated deletion leads to neocentromere formation in orangutans

Centromeres ensure faithful chromosome segregation, yet how new centromeres arise and replace canonical ones remains poorly understood. Here, we investigate a polymorphic centromere repositioning event on the orangutan chromosome 10 using near-telomere-to-telomere assemblies, epigenetic profiling, and population-scale data. We identify striking heterogeneity in canonical centromeres, ranging from large, higher-order repeat -satellite arrays to short, monomeric -satellite tracts, alongside the emergence of neocentromeres lacking -satellite DNA. We show a segmental duplication-mediated deletion of 3.6 Mbp that removed the higher-order repeat array, promoting centromere repositioning and neocentromere formation. Phylogenetic analyses reveal complex evolutionary dynamics, including introgression and incomplete lineage sorting in orangutan lineages. These findings demonstrate that centromere identity can evolve through structural variation and epigenetic reprogramming, highlighting its remarkable plasticity in primate genomes.

genomics↗

Ancient genomes from the siege and destruction of Middle Bronze Age Roca Vecchia (Apulia, Italy) shed light on Aegean contacts and conflicts

BackgroundRoca Vecchia, an iconic Bronze Age stronghold in Apulia, Southern Italy, was completely destroyed during a siege between the end of the 15th century BCE and the beginning of the 14th century BCE. During the siege, seven of the local people hid within the stronghold walls. Two others, who could have been as well attackers as defenders, were found under the ruins of the main gate. The material culture found at Roca Vecchia and associated with the period of the siege includes Minoan-type pottery produced from local clay, imported Aegean pottery and an Aegean-type dagger, pointing to an established relationship between the site and the Minoan civilization. Therefore, the site offers an unprecedented opportunity to characterise the genetic components of the population inhabiting an indigenous settlement with increasing contacts with the Aegean world, and to shed light on the demic or cultural modes of the Minoan presence in the central Mediterranean. ResultsWith our work, we sampled six out of nine available unburied Middle Bronze Age individuals, contemporary with the siege and destruction of the site, and obtained genome-wide information for two individuals. When compared with available Minoan, Apulian and broadly Mediterranean genomes, the individuals showed a characteristic Bronze/Iron Age Italian peninsula genetic signature, with limited contribution from Minoans. ConclusionsWe conclude that the local population of Roca Vecchia, at the moment of the siege, was predominantly autochthonous, with a minoritarian Minoan component. A Minoan genetic signal is indeed likely present in one out of two analysed individuals who were certainly part of the dwellers of Roca Vecchia. This confirms previous hypotheses supposing that a nucleus of "foreigners" coming from the Minoan world was living in the site and mixed with locals. Archaeological data suggest that the Roca Vecchia Aegean population component probably increased in the following centuries.

genetics↗

Imputed transcriptional patterns in ancient genomes reveal molecular targets of selection

The genetically regulated component of molecular traits can be imputed from ancient genomes, though low genotyping quality and genetic drift may impair accurate expression prediction and results interpretation. We developed tissue-specific gene expression and alternative splicing prediction models and applied them to over a thousand imputed ancient genomes spanning 10,000 years of Western Eurasian history. We revealed gene regulatory patterns diverging with time, space and genomic ancestry by fitting predicted transcriptional profiles onto multivariable models including these factors. By interpreting associations with time as recent natural selection we identify hits mediated by transcriptional changes. Finally, we fine-mapped these selection signals to tissue-specific transcriptional traits, explicitly accounting for prediction uncertainty. Among others, we elucidate the spatial patterns and the regulatory features promoting selection at LCT, FADS1, SLC22A5/P4HA2, ACAD10/OAS3 and find novel signals of selection at TBIMB6, SORD2P and AC012370.3.

genomics↗

CENdetectHOR: a comprehensive tool for CENtromere profiling and HOR detection

Centromeres are essential for accurate chromosome segregation and are characterized by long arrays of repetitive satellite DNA, showing extensive variation in sequence, length, and organization across species. Despite extensive research, fully characterizing centromeric DNA has been challenging due to its repetitive nature and rapid evolution. Here, we present CENdetectHOR, a computational tool to identify and analyze higher-order repeat (HOR) arrays in centromeric regions across diverse organisms, requiring no a priori information. We validate its efficacy using human and arabidopsis genomes, demonstrating its ability to reveal the complexity and diversity of centromeric architectures. CENdetectHOR also recognizes HOR variants, elucidating interindividual and interspecific variations in centromeric regions. These findings establish CENdetectHOR as a powerful, versatile, and rapid tool for advancing research on centromere structure, evolution, and function.

genetics↗

Complete sequencing of ape genomes

We present haplotype-resolved reference genomes and comparative analyses of six ape species, namely: chimpanzee, bonobo, gorilla, Bornean orangutan, Sumatran orangutan, and siamang. We achieve chromosome-level contiguity with unparalleled sequence accuracy (<1 error in 500,000 base pairs), completely sequencing 215 gapless chromosomes telomere-to-telomere. We resolve challenging regions, such as the major histocompatibility complex and immunoglobulin loci, providing more in-depth evolutionary insights. Comparative analyses, including human, allow us to investigate the evolution and diversity of regions previously uncharacterized or incompletely studied without bias from mapping to the human reference. This includes newly minted gene families within lineage-specific segmental duplications, centromeric DNA, acrocentric chromosomes, and subterminal heterochromatin. This resource should serve as a definitive baseline for all future evolutionary studies of humans and our closest living ape relatives.

genomics↗

Fast and reliable ancestral reconstruction on ancient genotype data with non-negative Least square and Principal Component Analysis

The history of human populations has been strongly shaped by admixture events, contributing to the patterns of observed genetic diversity across populations. Given its significance for evolutionary and medical studies, many algorithms focusing on the inference of the genetic composition of admixed populations have been developed. In particular, the recent development of new ancestry estimation methods that consider the fragmentary nature of ancient genotype data, such as the f-statistics family and its derivations, have radically changed our understanding of the past. F-statistics capture similar genetic similarity information as Principal Component Analysis (PCA), which is widely used in population genetics to quantify genetic affinity between populations or individuals. In this study, we introduce ASAP (ASsessing ancestry proportions through Principal component Analysis) method that leverages PCA and Non-Negative Least Square (NNLS) to assess the ancestral compositions of admixed individuals given a large set of populations. We tested ASAP on different simulated models, incorporating high levels of missingness. Our results show its ability to reliably estimate ancestry across numerous scenarios, even those with a significant proportion of missing genotypes, in a fraction of the time required when using other tools. When harnessed on Eurasias genotype data, ASAP helped replicate and extend findings from previous studies proving to be a fast, efficient, and straightforward new ancestry estimation tool.

genomics↗

The Genomic portrait of the Picene culture: new insights into the Italic Iron Age and the legacy of the Roman expansion in Central Italy.

BackgroundThe Italic Iron Age was characterized by the presence of various ethnic groups partially examined from a genomic perspective. To explore the evolution of Iron Age Italic populations and the genetic impact of Romanization, we focused on the Picenes, one of the most fascinating pre-Roman civilizations, who flourished on the Middle Adriatic side of Central Italy between the 9th and the 3rd century BCE, until the Roman colonization. ResultsWe analyzed more than 50 samples, spanning more than 1,000 years of history from the Iron Age to Late Antiquity. Despite cultural diversity, our analysis reveals no major differences between the Picenes and other coeval populations, suggesting a shared genetic history of the Central Italian Iron Age ethnic groups. Nevertheless, a slight genetic differentiation between populations along the Adriatic and Tyrrhenian coasts can be observed, possibly due to genetic contacts between populations residing on the Italian and Balkan shores of the Adriatic Sea. Additionally, we found several individuals with ancestries deviating from their general population. Lastly, In the Late Antiquity period, the genetic landscape of the Middle Adriatic region drastically changed, indicating a relevant influx from the Near East. ConclusionsOur findings, consistently with archeological hypotheses, suggest genetic interactions across the Adriatic Sea during the Bronze/Iron Age and a high level of individual mobility typical of cosmopolitan societies. Finally, we highlighted the role of the Roman Empire in shaping genetic and phenotypic changes that greatly impacted the Italian peninsula.

genomics↗

Assessing the impact of 20th century internal migrations on the genetic structure of Estonia

There is emerging evidence that migration behaviour can be selective with respect to individuals genotypes. As a result, it can generate genotype-environment correlations at migration-associated loci that cannot be corrected by standard methods used in genetic association studies. Here, we explore this phenomenon by looking into the dynamics of the spatial distribution of polygenic scores (PGSs) in the Estonian Biobank. We show that contemporary migrations intensify inter-regional differences in PGSs for many traits, with the effect of educational attainment (EA) PGS being the strongest and, to a large extent, explaining inter-regional differences in other PGSs. This differentiation is mainly driven by the migration of individuals with relatively high PGS for EA to the two largest cities from the rest of the country. Importantly, we replicate this pattern within families: individuals migrating to the major cities have, on average, higher PGS for EA relative to their siblings residing in other regions of Estonia. This trend is observed for the period starting from the mid-20th century to the present, despite substantial changes in Estonian society during this period. Thus, we show that there is increasing genetic differentiation at trait-associated loci between most urbanized regions of Estonia versus the rest of the country, leading to genotype-environment correlations that cannot be fully corrected using standard approaches. We also provide evidence for direct genetic effects on migration behaviour based on sibling analysis and discuss potential links between migration and EA.

genetics↗

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↗

Genetic heritage of the BaPhuthi highlights an over ethnicised notion of 'Bushman' in the Maloti-Drakensberg, Southern Africa

Using contemporary people as proxies for ancient communities is a contentious but necessary practice in anthropology. In Southern Africa, the distinction between the Cape KhoeSan and eastern KhoeSan remains unclear as ethnicity labels are continually changed through time and most communities were extirpated. The eastern KhoeSan may reflect an essentialistic biological distinction from neighbouring Bantu-speaking communities or it may not be tied to race and instead denote communities with a nomadic life-way distinct from agro-pastoralism. The BaPhuthi of the 1800s in the Maloti-Drakensberg, Southern Africa had a substantial San constituency and a life-way of nomadism, cattle raiding, and horticulture. The BaPhuthi heritage could provide insights into the history of the eastern KhoeSan. We examine for the first time genetic affinities of 23 BaPhuthi to distinguish if KhoeSan ancestry reflects biologically distinct heritage or a shared life-way. Data were merged with 52 global populations. The Principle Component Analysis, ADMIXTURE clustering and F3 tests show no support for a unique eastern KhoeSan ancestry distinct from other KhoeSan or southern Bantu-speaking communities. The BaPhuthi have strong affinities with Nguni communities, as the non-Nguni show strong evidence of recent African admixture possibly related to late-iron age migrations. The BaPhuthi may have an interesting connection to the early iron-age Bantu-speaking communities as MALDER detected no signals for late-iron age admixture. We demonstrate how the essentialistic understanding of references in historic literature creates misconstrued notions of ethnic/biological distinctions when San and Bushman may have reflected ambiguous references to the non-sedentary polities and practices.

genomics↗

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↗

Ancestral contributions to contemporary European complex traits

The contemporary European genetic makeup formed in the last 8000 years as the combination of three main genetic components: the local Western Hunter-Gatherers, the incoming Neolithic Farmers from Anatolia and the Bronze Age component from the Pontic Steppes. When meeting into the post-Neolithic European environment, the genetic variants accumulated during their three distinct evolutionary histories mixed and came into contact with new environmental challenges. Here we investigate how this genetic legacy reflects on the complex trait landscape of contemporary European populations, using the Estonian Biobank as a case study. For the first time we directly connect the phenotypic information available from biobank samples with the genetic similarity to these ancestral groups, both at a genome-wide level and focusing on genomic regions associated with each of the 27 complex traits we investigated. We also found SNPs connected to pigmentation, cholesterol, sleep, diastolic blood pressure, and body mass index (BMI) to show signals of selection following the post Neolithic admixture events. We recapitulate existing knowledge about pigmentation traits, corroborate the connection between Steppe ancestry and height and highlight novel associations. Among others, we report the contribution of Hunter Gatherer ancestry towards high BMI and low blood cholesterol levels. Our results show that the ancient components that form the contemporary European genome were differentiated enough to contribute ancestry-specific signatures to the phenotypic variability displayed by contemporary individuals in at least 11 out of 27 of the complex traits investigated here.

genomics↗

The genetic origin of Daunians and the Pan-Mediterranean southern Italian Iron Age context

The geographical location and shape of Apulia, a narrow land stretching out in the sea at the South of Italy, made this region a Mediterranean crossroads connecting Western Europe and the Balkans. Such movements culminated at the beginning of the Iron Age with the Iapygian civilization which consisted of three cultures: Peucetians, Messapians and Daunians. Among them, the Daunians left a peculiar cultural heritage, with one-of-a-kind stelae and pottery, but, despite the extensive archaeological literature, their origin has been lost to time. In order to shed light on this and to provide a genetic picture of Iron Age Southern Italy, we collected and sequenced human remains from three archaeological sites geographically located in Northern Apulia (the area historically inhabited by Daunians) and radiocarbon dated between 1157 and 275 calBCE. We find that Iron Age Apulian samples are still distant from the genetic variability of modern-day Apulians, they show a remarkable genetic heterogeneity, even though a few kilometers and centuries separate them, and they are well inserted into the Iron Age Pan-Mediterranean genetic landscape. Our study provides for the first time a window on the genetic make-up of pre-imperial Southern Italy, whose increasing connectivity within the Mediterranean landscape, would have contributed to laying the foundation for modern genetic variability. In this light, the genetic profile of Daunians may be compatible with an autochthonous origin, with plausible contributions from the Balkan peninsula.

genetics↗

Regulatory dissection of the severe COVID-19 risk locus introgressed by Neanderthals

Individuals infected with the SARS-CoV-2 virus present with a wide variety of phenotypes ranging from asymptomatic to severe and even lethal outcomes. Past research has revealed a genetic haplotype on chromosome 3 that entered the human population via introgression from Neanderthals as the strongest genetic risk factor for the severe COVID-19 phenotype. However, the specific variants along this introgressed haplotype that contribute to this risk and the biological mechanisms that are involved remain unclear. Here, we assess the variants present on the risk haplotype for their likelihood of driving the severe COVID-19 phenotype. We do this by first exploring their impact on the regulation of genes involved in COVID-19 infection using a variety of population genetics and functional genomics tools. We then perform an locus-specific massively parallel reporter assay to individually assess the regulatory potential of each allele on the haplotype in a multipotent immune-related cell line. We ultimately reduce the set of over 600 linked genetic variants to identify 4 introgressed alleles that are strong functional candidates for driving the association between this locus and severe COVID-19. These variants likely drive the locus impact on severity by putatively modulating the regulation of two critical chemokine receptor genes: CCR1 and CCR5. These alleles are ideal targets for future functional investigations into the interaction between host genomics and COVID-19 outcomes.

genetics↗

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↗

Continental-scale genomic analysis suggests shared post-admixture adaptation in Americas

American populations are one of the most interesting examples of recently admixed groups, where ancestral components from three major continental human groups (Africans, Eurasians and Native Americans) have admixed within the last 15 generations. Recently, several genetic surveys focusing on thousands of individuals shed light on the geography, chronology and relevance of these events. However, despite the fact that gene-flow could drive adaptive evolution, it is not clear whether and how natural selection acted on the resulting genetic variation in the Americas. In this study, we analysed the patterns of local ancestry of genomic fragments in genome-wide data for [~]6,000 admixed individuals from ten American countries. In doing so, we identified regions characterized by a Divergent Ancestry Profile (DAP), in which a significant over or under ancestral representation is evident. Our results highlighted a series of genomic regions with Divergent Ancestry Profiles (DAP) associated with immune system response and relevant medical traits, with the longest DAP region encompassing the Human Leukocyte Antigen locus. Furthermore, we found that DAP regions are enriched in genes linked to cancer-related traits and autoimmune diseases. Then, analyzing the biological impact of these regions, we showed that natural selection could have acted preferentially towards variants located in coding and non-coding transcripts, and characterized by a high deleteriousness score. Taken together, our analyses suggest that shared patterns of post admixture adaptation occurred at continental scale in the Americas, affecting more often functional and impactful genomic variants.

genomics↗

Revisiting the Out of Africa event with a novel Deep Learning approach

Anatomically modern humans evolved around 300 thousand years ago in Africa1. Modern humans started to appear in the fossil record outside of Africa about 100 thousand years ago though other hominins existed throughout Eurasia much earlier2-4. Recently, several researchers argued in favour of a single out of Africa event for modern humans based on whole-genome sequences analyses5-7. However, the single out of Africa model is in contrast with some of the findings from fossil records, which supports two out of Africa8,9, and uniparental data, which proposes back to Africa movement10,11. Here, we used a novel deep learning approach coupled with Approximate Bayesian Computation and Sequential Monte Carlo to revisit these hypotheses from the whole genome sequence perspective. Our results support the back to Africa model over other alternatives. We estimated that there are two successive splits between Africa and out of African populations happening around 60-80 thousand years ago and separated by 12-13 thousand years. One of the populations resulting from the more recent split has to a large extent replaced the older West African population while the other one has founded the out of Africa populations.

genetics↗

Fine-scale population structure reveals high genetic heterogeneity of the Kuwaiti population in the Arabian Peninsula

Recent studies have showed the diverse genetic architecture of the highly consanguineous populations inhabiting the Arabian Peninsula. Consanguinity coupled with heterogeneity is complex and makes it difficult to understand the bases of population-specific genetic diseases in the region. Therefore, comprehensive genetic characterization of the populations at the finest scale is warranted. Here, we revisit the genetic structure of the Kuwait population by analyzing genome-wide single nucleotide polymorphisms data from 583 Kuwaiti individuals sorted into three subgroups. We envisage a diverse demographic genetic history among the three subgroups based on drift and allelic sharing with modern and ancient individuals. Furthermore, our comprehensive haplotype-based analyses disclose a high genetic heterogeneity among the Kuwaiti populations. We infer the major sources of ancestry within the newly defined groups; one with an obvious predominance of sub-Saharan/Western Africa mostly comprising Kuwait-B individuals, and other with West Eurasia including Kuwait-P and Kuwait-S individuals. Overall, our results recapitulate the historical population movements and reaffirm the genetic imprints of the legacy of continental trading in the region. Such deciphering of fine-scale population structure and their regional genetic heterogeneity would provide clues to the uncharted areas of disease-gene discovery and related associations in populations inhabiting the Arabian Peninsula.

genomics↗