Identification of African swine fever virus-like elements in the soft tick genome provides insights into the virus’ evolution

BACKGROUND: African swine fever virus (ASFV) is a most devastating pathogen affecting swine. In 2007, ASFV was introduced into Eastern Europe where it continuously circulates and recently reached Western Europe and Asia, leading to a socio-economic crisis of global proportion. In Africa, where ASFV was first described in 1921, it is transmitted between warthogs and soft ticks of the genus Ornithodoros in a so-called sylvatic cycle. However, analyses into this virus’ evolution are aggravated by the absence of any closely related viruses. Even ancient endogenous viral elements, viral sequences integrated into a host’s genome many thousand years ago that have proven extremely valuable to analyse virus evolution, remain to be identified. Therefore, the evolution of ASFV, the only known DNA virus transmitted by arthropods, remains a mystery. - RESULTS: For the identification of ASFV-like sequences, we sequenced DNA from different recent Ornithodoros tick species, e.g. O. moubata and O. porcinus, O. moubata tick cells and also 100-year-old O. moubata and O. porcinus ticks using high-throughput sequencing. We used BLAST analyses for the identification of ASFV-like sequences and further analysed the data through phylogenetic reconstruction and molecular clock analyses. In addition, we performed tick infection experiments as well as additional small RNA sequencing of O. moubata and O. porcinus soft ticks. - CONCLUSION: Here, we show that soft ticks of the Ornithodoros moubata group, the natural arthropod vector of ASFV, harbour African swine fever virus-like integrated (ASFLI) elements corresponding to up to 10% (over 20 kb) of the ASFV genome. Through orthologous dating and molecular clock analyses, we provide data suggesting that integration could have occurred over 1.47 million years ago. Furthermore, we provide data showing ASFLI-element specific siRNA and piRNA in ticks and tick cells allowing for speculations on a possible role of ASFLI-elements in RNA interference-based protection against ASFV in ticks. We suggest that these elements, shaped through many years of co-evolution, could be part of an evolutionary virus-vector ‘arms race’, a finding that has not only high impact on our understanding of the co-evolution of viruses with their hosts but also provides a glimpse into the evolution of ASFV.Background Results - Evidence of ASFLI-elements in the O. moubata tick cell genome - Phylogenetic analysis shows ASFLI-elements are close relatives of ASFV sequences - ASFLI-elements are present in recently sampled O.moubata, O. porcinus and approx. 100-year-old O.moubata and O. porcinus field-collected ticks from Africa - Phylogenetic reconstruction using full-length mitochondrial genomes of soft ticks reveals a possible integration of an ASFLI-element might have occurred over 1.46–1.47 million years ago (mya) - Molecular clock analyses using ASFLI-elements from different Ornithodoros species provide an estimate for a time to the most recent common ancestor consistent with orthologous dating - Ornithodoros tick species and tick cell lines show differences in the infectability with various ASFV genotype isolates - RNA sequencing demonstrates ASFLI-element-specific mRNA—small-interfering and piwi-interacting RNAs in tick cells - The reconstructed ASFLI-A104R protein is highly similar to its ASFV homologue but is not expressed in tick cell lines Discussion Conclusion Methods - Virus strains - Tick rearing, tick infection and tick cell cultures - Nucleic acid extraction - Oligonucleotide design - PCR - qPCR - RT-qPCR - Sanger sequencing - Next-generation sequencing - Amplicon sequencing for assembly validation - Data analysis - Phylogenetic analysis - Clock rate estimates and Bayesian time-scaled trees - Protein expression and purification in E. coli and rabbit immunisation - Transfection - SDS-PAGE and immunoblotting - Statistical analysi

The genetic prehistory of the Greater Caucasus

5月16日，厦门大学人类学系、德国马普所、德国考古所、俄罗斯文化遗产联合会、奥地利维也纳大学人类学系、爱尔兰都柏林大学学院考古系、罗蒙诺索夫莫斯科国立大学考古系和人类学博物馆、俄罗斯国立东方艺术博物馆、俄罗斯联邦达吉斯坦考古与民族志研究所历史系、美国韦尔斯利学院人类学系、瑞士巴塞尔大学史前与考古科学研究所、德国国家遗产博物馆等36家单位的46位共同作者组成的国际合作团队在BioRxiv上预发表论文《The genetic prehistory of the Greater Caucasus》，厦门大学人类学系王传超研究员为论文的第一作者和通讯作者，也是该国际团队中的唯一一位来自中国的合作者。【Abstract】Archaeogenetic studies have described the formation of Eurasian 'steppe ancestry' as a mixture of Eastern and Caucasus hunter-gatherers. However, it remains unclear when and where this ancestry arose and whether it was related to a horizon of cultural innovations in the 4th millennium BCE that subsequently facilitated the advance of pastoral societies likely linked to the dispersal of Indo-European languages. To address this, we generated genome-wide SNP data from 45 prehistoric individuals along a 3000-year temporal transect in the North Caucasus. We observe a genetic separation between the groups of the Caucasus and those of the adjacent steppe. The Caucasus groups are genetically similar to contemporaneous populations south of it, suggesting that - unlike today - the Caucasus acted as a bridge rather than an insurmountable barrier to human movement. The steppe groups from Yamnaya and subsequent pastoralist cultures show evidence for previously undetected Anatolian farmer-related ancestry from different contact zones, while Steppe Maykop individuals harbour additional Upper Palaeolithic Siberian and Native American related ancestry.This work was funded by the Max Planck Society and the German Archaeological Institute (DAI). C.C.W. was funded by Nanqiang Outstanding Young Talents Program of Xiamen University (X2123302) and the Fundamental Research Funds for the Central Universities. 该研究由德国马普学会、德国考古所、厦门大学南强青年拔尖人才支持计划资助

Genomic and dietary discontinuities during the Mesolithic and Neolithic in Sicily

Sicily is a key region for understanding the agricultural transition in the Mediterranean because of its central position. Here, we present genomic and stable isotopic data for 19 prehistoric Sicilians covering the Mesolithic to Bronze Age periods (10,700-4,100 yBP). We find that Early Mesolithic hunter-gatherers (HGs) from Sicily are a highly drifted lineage of the Early Holocene western European HGs, whereas Late Mesolithic HGs carry ∼20% ancestry related to northern and (south) eastern European HGs, indicating substantial gene flow. Early Neolithic farmers are genetically most similar to farmers from the Balkans and Greece, with only ∼7% of ancestry from local Mesolithic HGs. The genetic discontinuities during the Mesolithic and Early Neolithic match the changes in material culture and diet. Three outlying individuals dated to ∼8,000 yBP; however, suggest that hunter-gatherers interacted with incoming farmers at Grotta dell'Uzzo, resulting in a mixed economy and diet for a brief interlude at the Mesolithic-Neolithic transition.Funding. The Max Planck Society financed the genetic, isotopic, and radiocarbon analyses. S. Talamo has received funding from the European Research Council under the European Union’s Horizon 2020 Research and Innovation Program (grant agreement No. 803147 RESOLUTION, https://site.unibo.it/resolution-erc/en).Peer reviewe

Ancient human genome-wide data from a 3000-year interval in the Caucasus corresponds with eco-geographic regions

Archaeogenetic studies have described the formation of Eurasian 'steppe ancestry' as a mixture of Eastern and Caucasus hunter-gatherers. However, it remains unclear when and where this ancestry arose and whether it was related to a horizon of cultural innovations in the 4 th millennium BCE that subsequently facilitated the advance of pastoral societies in Eurasia. Here we generated genome-wide SNP data from 45 prehistoric individuals along a 3000-year temporal transect in the North Caucasus. We observe a genetic separation between the groups of the Caucasus and those of the adjacent steppe. The northern Caucasus groups are genetically similar to contemporaneous populations south of it, suggesting human movement across the mountain range during the Bronze Age. The steppe groups from Yamnaya and subsequent pastoralist cultures show evidence for previously undetected farmer-related ancestry from different contact zones, while Steppe Maykop individuals harbour additional Upper Palaeolithic Siberian and Native American related ancestry

Herbivory elicits changes in green leaf volatile production via jasmonate signaling and the circadian clock

The timing of plant volatile emissions is important for a robust indirect defense response. Green leaf volatiles (GLVs) are emitted by plants upon damage but can be suppressed by herbivore‐associated elicitors, and the abundance and composition of GLVs vary depending on the timing of herbivore attack. We show that the GLV biosynthetic enzyme HYDROPEROXIDE LYASE (HPL) is transcriptionally regulated by the circadian clock in Nicotiana attenuata. In accordance with transcript abundance of NaHPL, GLV aldehyde pools in intact leaves peaked at night and at subjective night under diurnal and continuous light conditions, respectively. Moreover, although the basal abundance of NaHPL transcripts is upregulated by jasmonate (JA) signaling, JA does not regulate the reduction of NaHPL transcript abundance in damaged leaves by simulated herbivore treatment. Unexpectedly, the plant circadian clock was strongly altered when Manduca sexta larvae fed on N. attenuata, and this was also independent of JA signaling. Lastly, the temporal dynamics of NaHPL transcripts and total GLV emissions were strongly altered by M. sexta larval feeding. Our data suggest that the temporal dynamics of emitted GLV blends result from a combination of damage, JA signaling, herbivore‐associated elicitors, and the plant circadian clock

Genomic and dietary discontinuities during the Mesolithic and Neolithic in Sicily

Sicily is a key region for understanding the agricultural transition in the Mediterranean because of its central position. Here, we present genomic and stable isotopic data for 19 prehistoric Sicilians covering the Mesolithic to Bronze Age periods (10,700-4,100 yBP). We find that Early Mesolithic hunter-gatherers (HGs) from Sicily are a highly drifted lineage of the Early Holocene western European HGs, whereas LateMesolithic HGs carry similar to 20% ancestry related to northern and (south) eastern European HGs, indicating substantial gene flow. Early Neolithic farmers are genetically most similar to farmers from the Balkans and Greece, with only similar to 7% of ancestry from local Mesolithic HGs. The genetic discontinuities during the Mesolithic and Early Neolithic match the changes in material culture and diet. Three outlying individuals dated to similar to 8,000 yBP; however, suggest that hunter-gatherers interacted with incoming farmers at Grotta dell'Uzzo, resulting in a mixed economy and diet for a brief interlude at the Mesolithic-Neolithic transition.N

Emergence of human-adapted Salmonella enterica is linked to the Neolithization process

It has been hypothesized that the Neolithic transition towards an agricultural and pastoralist economy facilitated the emergence of human-adapted pathogens. Here, we recovered eight Salmonella enterica subsp. enterica genomes from human skeletons of transitional foragers, pastoralists and agropastoralists in western Eurasia that were up to 6,500 yr old. Despite the high genetic diversity of S. enterica, all ancient bacterial genomes clustered in a single previously uncharacterized branch that contains S. enterica adapted to multiple mammalian species. All ancient bacterial genomes from prehistoric (agro-)pastoralists fall within a part of this branch that also includes the human-specific S. enterica Paratyphi C, illustrating the evolution of a human pathogen over a period of 5,000 yr. Bacterial genomic comparisons suggest that the earlier ancient strains were not host specific, differed in pathogenic potential and experienced convergent pseudogenization that accompanied their downstream host adaptation. These observations support the concept that the emergence of human-adapted S. enterica is linked to human cultural transformations

Ten millennia of hepatitis B virus evolution

Hepatitis B virus (HBV) has been infecting humans for millennia and remains a global health problem, but its past diversity and dispersal routes are largely unknown. We generated HBV genomic data from 137 Eurasians and Native Americans dated between ~10,500 and ~400 years ago. We date the most recent common ancestor of all HBV lineages to between ~20,000 and 12,000 years ago, with the virus present in European and South American hunter-gatherers during the early Holocene. After the European Neolithic transition, Mesolithic HBV strains were replaced by a lineage likely disseminated by early farmers that prevailed throughout western Eurasia for ~4000 years, declining around the end of the 2nd millennium BCE. The only remnant of this prehistoric HBV diversity is the rare genotype G, which appears to have reemerged during the HIV pandemic.The research was funded by the Max Planck Society, the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (771234–PALEoRIDER, to W.H.; 805268–CoDisEASe to K. Bos; 834616–ARCHCAUCASUS to S.H.), the Slovak Academy of Sciences and the European Union’s Seventh Framework Programme and Marie Curie Actions under the Programme SASPRO (1340/03/03 to P.C.R.), the ERA.NET RUS Plus–S&T programm of the European Union’s Seventh Framework Programme (277–BIOARCCAUCASUS to S.Re. and S.H.), the Werner Siemens Stiftung (“Paleobiochemistry”, to CW), the Award Praemium Academiae of the Czech Academy of Sciences (to M.E.), the Institute of Archaeology of the Czech Academy of Sciences (RVO 67985912, to M.Dobe.), the Russian Foundation for Basic Research (19-09-00354a, to M.K.K. and V.V.K.; 19-78-10053 to SSh), the German Research Foundation (DFG-HA-5407/4-1–INTERACT to W.H. and RE2688/2 to S.Re.), the French National Research Agency (ANR-17-FRAL-0010–INTERACT, to M.F.D., M.Ri., S.Ro., S.Sai., D.Bi., and P.Le.), the Wenner-Gren Dissertation Fieldwork Grant (9558 to S.Sab.), and the Ministry of Education and Science of the Republic of Kazakhstan (AP08856654 to L.B.D., L.M., and E.Kh. and AP08857177 to A.Z.B.)