In this study, we present the results of community-engaged ancient DNA research initiated after the remains of 36 African-descended individuals dat…
Abstract Global warming poses a major threat to food security and necessitates the development of crop varieties that are resilient to future climatic instability. By evaluating 149 spring wheat lines in the field under yield potential and heat stressed conditions, we demonstrate how strategic integration of exotic material significantly increases yield under heat stress compared to elite lines, with no significant yield penalty under favourable conditions. Genetic analyses reveal three exotic-derived genetic loci underlying this heat tolerance which together increase yield by over 50% and reduce canopy temperature by approximately 2 °C. We identified an Ae. tauschii introgression underlying the most significant of these associations and extracted the introgressed Ae. tauschii genes, revealing candidates for further dissection. Incorporating these exotic alleles into breeding programmes could serve as a pre-emptive strategy to produce high yielding wheat cultivars that are resilient to the effects of future climatic uncertainty.
Every crop has a story. The story of breadfruit (Artocarpus altilis), an increasingly valued staple crop in tropical agroforestry systems, is filled with intrigue, oppression, and remains incomplete. The Caribbean is a major producer and consumer of breadfruit, yet most breadfruit there came from a single 1793 introduction aimed at providing a cheap food source for slaves forced to work on British plantations. St. Vincent was the first significant point of Caribbean introduction and played a vital role in subsequent breadfruit distribution throughout the region. Hundreds of cultivars are documented in breadfruit’s native Oceania. It remains a mystery, however, which ones were introduced to the Caribbean 230 years ago—still comprising the vast diversity found there today. Integrating local knowledge, historical documents and specimens, morphological data, and DNA, we identify eight major global breadfruit lineages—five of which are found in the Caribbean and likely represent the original 1793 introduction. Genetic data were able to match two Caribbean cultivar names confidently to their Oceania counterparts. Genetics and morphology together enabled additional possible matches. Many other named cultivars within lineages are too genetically similar to differentiate, highlighting difficulties of defining and identifying variation among clonally propagated triploid crops. Breadfruit is important in resilient agroforestry in tropical islands predicted to be especially affected by climate change. Findings reveal global links, building upon collective knowledge that can be used to inform breadfruit management. Results are also summarized in a brochure about breadfruit history and diversity in St. Vincent, and the Caribbean more broadly.
Herpes simplex virus 1 (HSV-1) encodes a family B DNA polymerase (Pol) capable of exonucleolytic proofreading whose functions have been extensively studied in the past. Early studies on the in vitro activity of purified Pol protein found that the enzymatic functions of the holoenzyme are largely separate. Consequently, exonuclease activity can be reduced or abolished by certain point mutations within catalytically important regions, with no or only minor effects on polymerase activity. Despite unimpaired polymerase activity, the recovery of HSV-1 mutants with a catalytically inactive exonuclease has been so far unsuccessful. Hence, mutations such as D368A, which abolish exonuclease activity, are believed to be lethal. Here, we show that HSV-1 can be recovered in the absence of Pol intrinsic exonuclease activity and demonstrate that a lack of proofreading causes the rapid accumulation of likely detrimental mutations. Although mutations that abolish exonuclease activity do not appear to be lethal, the lack of proofreading yields viruses with a suicidal phenotype that cease to replicate within few passages following reconstitution. Hence, we conclude that high replication fidelity conferred by proofreading is essential to maintain HSV-1 genome integrity and that a lack of exonuclease activity produces an initially viable but rapidly suicidal phenotype. However, stably replicating viruses with reduced exonuclease activity and therefore elevated mutation rates can be generated by mutating a catalytically less important site located within a conserved exonuclease domain. IMPORTANCE Recovery of fully exonuclease-deficient herpes simplex virus 1 (HSV-1) DNA polymerase mutants has been so far unsuccessful. However, exonuclease activity is not known to be directly essential for virus replication, and the lethal phenotype of certain HSV-1 polymerase mutants is thus attributed to factors other than exonuclease activity. Here, we showed that the recovery of a variety of exonuclease-deficient HSV-1 polymerase mutants is possible and that these mutants are initially replication competent. We, however, observed a progressive loss of mutant viability upon cell culture passaging, which coincided with the rapid accumulation of mutations in exonuclease-deficient viruses. We thus concluded that a lack of DNA proofreading in exonuclease-deficient viruses causes an initially viable but rapidly suicidal hypermutator phenotype and, consequently, the extinction of mutant viruses within few generations following recovery. This would make the absence of exonuclease activity the primary reason for the long-reported difficulties in culturing exonuclease-deficient HSV-1 mutants.
Historic records indicate that in 1909 the remains of 17 Maronite patriarchs were exhumed from their primary burial location and transferred to a collective secondary burial inside the Saint Marina chapel in an underground cave at the Qanubin monastery in the Northern Lebanese mountains. We used Church records, iconography, archaeology, anthropology, and ancient DNA (aDNA) analyses to investigate whether the remains found in the chapel might belong to the patriarchs. Further, we hoped to identify the remains of patriarch Estephan El Douaihy, one of the 17 patriarchs who was among those said to be buried in the chapel and who is in the process of being canonized by the Vatican. The entire secondary burial was excavated by horizontal ‘décapage’. Pairing of bones, and reconstruction were undertaken, and the Minimum Number of Individuals (MNI) was identified. Age at death was determined through senescence indicators and sex determination was determined from pelvic bone observations. There were only 16 complete crania represented in the collection, and these were targeted for aDNA analyses. The complete mitochondrial genomes were sequenced for all 16 samples and Y-chromosome haplogroups were able to be determined for four individuals. The evidence from the funerary stele, historical church records, osteological analyses and aDNA analyses when combined provide strong evidence to suggest that the 16 complete skulls present in the burial likely belong to 16 of the patriarchs exhumed in 1909.
The Istituti Zooprofilattici Sperimentali (IZSs) are public health institutes dealing with the aetiology and path-ogenesis of infectious diseases of domestic and wild animals. During Coronavirus Disease 2019 epidemic, the Italian Ministry of Health appointed the IZSs to carry out diagnostic tests for the detection of SARS-CoV-2 in human samples. In particular, the IZS of Abruzzo and Molise (IZS-Teramo) was involved in the diagnosis of SARS-CoV-2 through testing nasopharyngeal swabs by Real Time RT-PCR. Activities and infrastructures were reor-ganised to the new priorities, in a “One Health” framework, based on interdisciplinary, laboratory promptness, accreditation of the test for the detection of the RNA of SARS-CoV-2 in human samples, and management of confidentiality of sensitive data. The laboratory information system-SILAB-was implemented with a One Health module for managing data of human origin, with tools for the automatic registration of information improving the quality of the data. Moreover, the “National Reference Centre for Whole Genome Sequencing of microbial pathogens-database and bioinformatics analysis”-GENPAT-formally established at the IZS-Teramo, developed bioinformatics workflows and IT dashboard with ad hoc surveillance tools to support the metagenomics-based SARS-CoV-2 surveillance, providing molecular sequencing analysis to quickly intercept the variants circulating in the area. This manuscript describes the One Health system developed by adapting and integrating both SILAB and GENPAT tools for supporting surveillance during COVID-19 epidemic in the Abruzzo region, southern Italy. The developed dashboard permits the health authorities to observe the SARS-CoV-2 spread in the region, and by combining spatio-temporal information with metagenomics provides early evidence for the identification of emerging space-time clusters of variants at the municipality level. The implementation of the One Health module was designed to be easily modelled and adapted for the management of other diseases and future hypothetical events of pandemic nature.
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