Unravelling the resilience of the KGK VI population from the Gumelnița site (Romania) through stable isotopes.

The Gumelnița site belongs to the Kodjadermen-Gumelnița-Karanovo VI (KGK VI) communities (c. 4700-3900 cal BC) and comprises the tell-type settlement and its corresponding cemetery. This paper reconstructs the diet and lifeways of the Chalcolithic people in the northeastern Balkans using archaeological remains found at the Gumelnița site (Romania). A multi-bioarchaeological investigation (archaeobotany, zooarchaeology, anthropology) was conducted on vegetal, animal, and human remains, alongside radiocarbon dating and stable isotope analyses (δ13C, δ15N) of humans (n = 33), mammals (n = 38), reptiles (n = 3), fishes (n = 8), freshwater mussels shells (n = 18), and plants (n = 24). According to the results of δ13C and δ15N values and FRUITS, the inhabitants of Gumelnița had a diet based on crops and using natural resources, such as fish, freshwater molluscs and game. Although domestic fauna was occasionally exploited for meat, it had a role in providing secondary products. Crops were heavily manured, and chaff and other crop waste may have been necessary fodder for cattle and sheep. Dogs and pigs fed on human waste, although the diet of the latter is more similar to that of wild boars. Foxes had a diet close to dogs, which may indicate synanthropic behaviour. Radiocarbon dates were calibrated with the percentage of freshwater resources obtained by FRUITS. As a result, the corrected dates for the freshwater reservoir effect (FRE) have a delay of an average of 147 years. According to our data, this agrarian community developed a subsistence strategy under the pressure of some climatic changes that started after 4300 cal BC, corresponding to KGK VI rapid collapse/decline episode tracked recently (that begins around 4350 cal BC). This matching of our data in the two models (climatic and chrono-demographic) allowed us to capture the economic strategies that led to the resilience of those people more than other contemporary KGK VI communities.

Paleogenomic Evidence for Multi-generational Mixing between Neolithic Farmers and Mesolithic Hunter-Gatherers in the Lower Danube Basin.

The transition from hunting and gathering to farming involved profound cultural and technological changes. In Western and Central Europe, these changes occurred rapidly and synchronously after the arrival of early farmers of Anatolian origin [1-3], who largely replaced the local Mesolithic hunter-gatherers [1, 4-6]. Further east, in the Baltic region, the transition was gradual, with little or no genetic input from incoming farmers [7]. Here we use ancient DNA to investigate the relationship between hunter-gatherers and farmers in the Lower Danube basin, a geographically intermediate area that is characterized by a rapid Neolithic transition but also by the presence of archaeological evidence that points to cultural exchange, and thus possible admixture, between hunter-gatherers and farmers. We recovered four human paleogenomes (1.1× to 4.1× coverage) from Romania spanning a time transect between 8.8 thousand years ago (kya) and 5.4 kya and supplemented them with two Mesolithic genomes (1.7× and 5.3×) from Spain to provide further context on the genetic background of Mesolithic Europe. Our results show major Western hunter-gatherer (WHG) ancestry in a Romanian Eneolithic sample with a minor, but sizeable, contribution from Anatolian farmers, suggesting multiple admixture events between hunter-gatherers and farmers. Dietary stable-isotope analysis of this sample suggests a mixed terrestrial/aquatic diet. Our results provide support for complex interactions among hunter-gatherers and farmers in the Danube basin, demonstrating that in some regions, demic and cultural diffusion were not mutually exclusive, but merely the ends of a continuum for the process of Neolithization.

Unravelling the complexity of domestication: a case study using morphometrics and ancient DNA analyses of archaeological pigs from Romania.

Current evidence suggests that pigs were first domesticated in Eastern Anatolia during the ninth millennium cal BC before dispersing into Europe with Early Neolithic farmers from the beginning of the seventh millennium. Recent ancient DNA (aDNA) research also indicates the incorporation of European wild boar into domestic stock during the Neolithization process. In order to establish the timing of the arrival of domestic pigs into Europe, and to test hypotheses regarding the role European wild boar played in the domestication process, we combined a geometric morphometric analysis (allowing us to combine tooth size and shape) of 449 Romanian ancient teeth with aDNA analysis. Our results firstly substantiate claims that the first domestic pigs in Romania possessed the same mtDNA signatures found in Neolithic pigs in west and central Anatolia. Second, we identified a significant proportion of individuals with large molars whose tooth shape matched that of archaeological (likely) domestic pigs. These large 'domestic shape' specimens were present from the outset of the Romanian Neolithic (6100-5500 cal BC) through to later prehistory, suggesting a long history of admixture between introduced domestic pigs and local wild boar. Finally, we confirmed a turnover in mitochondrial lineages found in domestic pigs, possibly coincident with human migration into Anatolia and the Levant that occurred in later prehistory.

Treatment of hepatitis B virus-infected cells with alpha-glucosidase inhibitors results in production of virions with altered molecular composition and infectivity.

Trimming of the N-glycans attached to the envelope proteins of hepatitis B virus (HBV) is required in different steps of the viral life cycle. Inhibition of the host enzymes alpha-glucosidases, involved in the endoplasmic reticulum (ER)-associated processing of the N-linked glycans, results in misfolding of the HBV envelope proteins, prevention of HBV secretion and accumulation of viral DNA within infected cells. However, the impact of these effects on HBV morphogenesis and infectivity of the viral particles that are still released from cells with inhibited alpha-glucosidase has not been addressed so far. Using N-butyldeoxynojirimycin (NB-DNJ), a competitive inhibitor of the ER alpha-glucosidases, we analyzed the role of these enzymes on HBV assembly and infectivity of the virions released from HepG2.2.2.15 cells. HBV secreted from drug-treated cells contained an envelope with altered composition of the disulfide-linked oligomers and no detectable middle (M) protein. These molecular changes had a significant effect on HBV infectivity, reducing it to 20% compared to controls, for the highest concentrations of NB-DNJ used. Our data show for the first time that an active alpha-glucosidase activity is crucial for production of infectious HBV and provide new insights into the controversial role of the M protein in this process.