Biology subjects

Ozdogan, K. T.

Publications and source records attributed to Ozdogan, K. T..

5 recordsLinked to original sources

bioRxiv2025

Towards an archaeological workflow for sedaDNA sample collection: methods and best practices for minimizing surface contamination

SedaDNA has been successfully recovered from diverse contexts, enabling researchers to address paleoenvironmental questions such as ecosystem changes and climatic shifts, along with archaeological questions related to past human activities, diet, health, and interactions with their environment. Despite its potential, the reliability of sedaDNA data heavily depends on proper sampling and handling practices. Contamination remains a significant challenge in ancient DNA research, profoundly impacting data integrity and interpretation. Consequently, numerous studies have underscored the importance of minimizing contamination levels. Nonetheless, a challenge arises in implementing this in daily archaeological practice, as a specialized DNA expert is not always available. This study suggests two customised workflows of commonly used sedaDNA sampling techniques, redesigned for archaeologists without sedaDNA expertise. We test their effectiveness in the field. To benchmark these protocols, we applied artificial DNA contaminants onto sediment surfaces before sampling. Subsequently, we evaluate archaeologists effectiveness in reducing surface contamination by quantifying the level of artificial DNA detected. Finally, we compare results between samples taken by archaeologists with and without sedaDNA expertise. Our results demonstrate that existing sampling protocols, when slightly adapted to the needs of archaeologists, significantly minimize surface contamination to the point that they provide high-quality extraction. Additionally, our findings suggest that subsampling sediments with minimal surface contamination from previously collected materials is viable, emphasizing the potential of archived sediment collections for sedaDNA analysis.

genomics↗

bioRxiv2024

A complete mitochondrial genome of a Roman-era Plasmodium falciparum

Malaria has historically been one of the leading infection-related causes of death in human populations. To this day, it continues to pose a significant public health threat in African countries, particularly among children. Humans are affected by five Plasmodium species, with Plasmodium falciparum being the most lethal. The study of pathogenic DNA from ancient human remains has been vital in understanding the origin, evolution, and virulence of human-infecting pathogens. However, there have been no complete pre-20th century mitochondrial DNA (mtDNA) or genomic sequences of Plasmodium falciparum reported to date. This gap in knowledge makes it difficult to understand the genetic dynamics of this pathogen in the past. The difficulty in identifying ancient malaria cases through bioarchaeology and the infrequent presence of Plasmodium DNA in ancient bones contribute to these limitations. Here, we present the first complete mtDNA genome of P. falciparum recovered from an archaeological skeleton (a 2nd century CE Roman individual from Italy). The study of the 43-fold mtDNA genome supports the hypothesis of an Indian origin for P. falciparum in Europe and provides evidence for the genetic continuity of this lineage over the past 2,000 years. Additionally, our research highlights that extensive sampling may be necessary for malaria screening to gain insights into the evolution of this vector-borne disease from archaeological samples.

genomics↗

bioRxiv2022

Stable population structure in Europe since the Iron Age, despite high mobility

Ancient DNA research in the past decade has revealed that European population structure changed dramatically in the prehistoric period (14,000-3,000 years before present, YBP), reflecting the widespread introduction of Neolithic farmer and Bronze Age Steppe ancestries. However, little is known about how population structure changed from the historical period onward (3,000 YBP - present). To address this, we collected whole genomes from 204 individuals from Europe and the Mediterranean, many of which are the first historical period genomes from their region (e.g. Armenia and France). We found that most regions show remarkable inter-individual heterogeneity. At least 7% of historical individuals carry ancestry uncommon in the region where they were sampled, some indicating cross-Mediterranean contacts. Despite this high level of mobility, overall population structure across western Eurasia is relatively stable through the historical period up to the present, mirroring geography. We show that, under standard population genetics models with local panmixia, the observed level of dispersal would lead to a collapse of population structure. Persistent population structure thus suggests a lower effective migration rate than indicated by the observed dispersal. We hypothesize that this phenomenon can be explained by extensive transient dispersal arising from drastically improved transportation networks and the Roman Empires mobilization of people for trade, labor, and military. This work highlights the utility of ancient DNA in elucidating finer scale human population dynamics in recent history.

genetics↗

bioRxiv2021

Diverse northern Asian and Jomon-related genetic structure discovered among socially complex Three Kingdoms period Gaya region Koreans

The genetic history of prehistoric and protohistoric Korean populations is not well understood due to the lack of ancient Korean genomes. Here, we report the first paleogenomic data from Korea; eight shotgun-sequenced genomes (0.7x[~]6.1x coverage) from two archeological sites in Gimhae: Yuha-ri shell mound and Daesung-dong tumuli, the most important funerary complex of the Gaya confederacy. All eight individuals are from the Korean Three Kingdoms period (4th-7th century CE), during which there is archaeological evidence of extensive trade connections with both northern (modern-day China) and eastern (modern-day Japan) kingdoms. All genomes are best modeled as an admixture between a northern-Chinese Iron Age genetic source and a Japanese-Jomon-related ancestry. The proportion of Jomon-related ancestry suggests the presence of two genetic groups within the population. The observed substructure indicates diversity among the Gaya population that is not related to either social status or sex. Teaser1,700-year-old genomes reveal the genetic diversity of ancient Koreans in the Gimhae region.

evolutionary biology↗

bioRxiv2021

Genome-scale sequencing and analysis of human, wolf and bison DNA from 25,000 year-old sediment

Archaeological sediments have been shown to preserve ancient DNA, but so far have not yielded genome-scale information of the magnitude of skeletal remains. We retrieved and analysed human and mammalian low-coverage nuclear and high-coverage mitochondrial genomes from Upper Palaeolithic sediments from Satsurblia cave, western Georgia, dated to 25,000 years ago. First, a human female genome with substantial basal Eurasian ancestry, which was an ancestry component of the majority of post-Ice Age people in the Near East, North Africa, and parts of Europe. Second, a wolf genome that is basal to extant Eurasian wolves and dogs and represents a previously unknown, likely extinct, Caucasian lineage that diverged from the ancestors of modern wolves and dogs before these diversified. Third, a bison genome that is basal to present-day populations, suggesting that population structure has been substantially reshaped since the Last Glacial Maximum. Our results provide new insights into the late Pleistocene genetic histories of these three species, and demonstrate that sediment DNA can be used not only for species identification, but also be a source of genome-wide ancestry information and genetic history. HighlightsO_LIWe demonstrate for the first time that genome sequencing from sediments is comparable to that of skeletal remains C_LIO_LIA single Pleistocene sediment sample from the Caucasus yielded three low-coverage mammalian ancient genomes C_LIO_LIWe show that sediment ancient DNA can reveal important aspects of the human and faunal past C_LIO_LIEvidence of an uncharacterized human lineage from the Caucasus before the Last Glacial Maximum C_LIO_LI[~]0.01-fold coverage wolf and bison genomes are both basal to present-day diversity, suggesting reshaping of population structure in both species C_LI

developmental biology↗