Biology subjects

Larena, M.

Publications and source records attributed to Larena, M..

5 recordsLinked to original sources

bioRxiv2025

Ancestry, admixture, and pathogens in contemporaneous Neolithic farmers and foragers on the Island of Gotland

Two archaeological cultural complexes coexisted on Gotland for over 500 years, between [~]3300 and 2800 calBCE, i.e. the Neolithic Funnelbeaker culture (FBC), and the Pitted ware culture (PWC). The ancestry of the FBC farmers and PWC marine foragers largely aligns with European Neolithic Farmers and European Mesolithic foragers, respectively, but the direct interactions between the groups on Gotland is not understood. We present a Middle Neolithic (MN) high-coverage genome and a Late Neolithic (LN) low-coverage genome from the Ansarve FBC dolmen. We investigate ancestry, admixture, and pathogens among these MN farmers (n =6), foragers (n=19), and a LN individual. We find that recent gene-flow between farmers and foragers could have taken place, although most gene-flow happened prior to their coexistence on the island. We also find evidence of different Yersinia pestis strains in the three cultural groups, showing that the pestis was widespread among groups with different subsistence strategies.

genomics↗

bioRxiv2025

Revisiting the African mtDNA Landscape: A Continental Update from Complete Mitochondrial Genomes

AbstractAfrica harbors the richest diversity of mitochondrial DNA lineages, reflecting its central role in human evolutionary history. Early studies of mtDNA variation provided the first genetic evidence for the African origin of modern humans. With complete mitochondrial genome sequencing, we can now reconstruct maternal lineages with high resolution, yet large parts of the continent remain underrepresented. Using a newly developed long-range sequencing assay, we generated 1,288 complete mitochondrial genomes from 14 countries across sub-Saharan Africa, focusing on previously understudied regions. We combined these with over 3,600 publicly available African mitogenomes to produce a comprehensive dataset and updated overview of maternal genetic diversity across the continent. We contextualized this diversity with autosomal structure and information on major human expansions, integrating archaeological and linguistic evidence. Our analyses reveal a demographic expansion of Niger-Congo speakers around 17 thousand years ago (kya), followed by a second expansion associated with Bantuspeaking groups around 6 kya. We identify haplogroup L3e as a key marker of this early Bantu expansion, tracking its spread across sub-Saharan Africa. Distinct demographic signatures also emerge for different geographic sub-branches of Bantu speakers. These findings highlight the power of mitochondrial DNA to trace maternal ancestry and demographic history in Africa, while also acknowledging its limitations for phylogeographic reconstruction.

evolutionary biology↗

bioRxiv2024

Wide-scale Geographical Analysis of Genetic Ancestry in the South African Coloured Population

The South African Coloured (SAC) population, a prominent admixed population in South Africa, reflects centuries of migration, admixture, and historical segregation. Descendants of local Khoe-San and Bantu-speaking populations, European settlers, and enslaved individuals from Africa and Asia, SAC individuals embody diverse ancestries. This study investigates the genetic makeup of SAC individuals, utilizing autosomal genotypes, mitochondrial DNA and Y-chromosome data. We analyze new genotype data for 125 SAC individuals from seven locations. Our analysis, based on a dataset comprising 356 SAC individuals from 22 geographic locations, revealed significant regional variations in ancestry. Khoe-San ancestry predominates in 14 locations, highlighting its lasting influence. Inland regions exhibit higher proportions of Khoe-San ancestry, eastern regions show more Bantu-speaker/West African ancestry, and western/coastal areas, particularly around Cape Town, display increased Asian ancestry. These patterns reflect historical migrations and settlement patterns. Additionally, sex-biased admixture ratios show male-biased admixture from East Africans and Europeans, and female-biased admixture from Khoe-San populations, which is supported by mitochondrial and Y-chromosome data. This research underscores the importance of studying the SAC population to understand South Africas historical migrations, providing insights into the complex genetic heritage of South Africans.

evolutionary biology↗

bioRxiv2022

Archaic humans have contributed to large-scale variation in modern human T cell receptor genes

The human T cell receptor (TCR) genes are critical for mediating immune responses to pathogens, tumors and regulating self-antigen recognition. A detailed analysis and validation of expressed TCR alpha, beta, gamma, and delta genes in 45 donors from 4 human populations: African, East Asian, South Asian, and European, revealed a total of 175 novel TCR variable and junctional alleles. The majority of novel alleles contained coding changes and were present at widely differing frequencies in the populations, a finding confirmed using DNA samples and sequences from the 1000 Genomes Project. Importantly, we identified three Neanderthal-derived, introgressed TCR regions, including a highly divergent novel TRGV4 variant, present in all archaic assemblies, that was frequent in all modern Eurasian population groups. Our results demonstrate significant variation in TCR genes at both individual and population levels, providing a strong incentive for including allelic variation in studies of TCR function in human biology.

immunology↗

bioRxiv2022

Demographic history and genetic structure in pre-Hispanic Central Mexico

Aridoamerica and Mesoamerica are two distinct cultural areas that hosted numerous pre-Hispanic civilizations between 2,500 BCE and 1,521 CE. The division between these regions shifted southward due to severe droughts ca. 1,100 years ago, allegedly driving demographic changes and population replacement in some sites in central Mexico. Here, we present shotgun genome-wide data from 12 individuals and 26 mitochondrial genomes from eight pre-Hispanic archaeological sites across Mexico, including two at the shifting border of Aridoamerica and Mesoamerica. We find population continuity spanning the climate change episode and a broad preservation of the genetic structure across present-day Mexico for the last 2,300 years. Lastly, we identify a contribution to pre-Hispanic populations of northern and central Mexico from an ancient unsampled ghost population.

genomics↗