Phylogenetic inference and species delimitation can be challenging in taxonomic groups that have recently radiated and where introgression produces conflicting gene trees, especially when species delimitation has traditionally relied on mitochondrial data and color pattern. Chromodoris, a genus of colorful and toxic nudibranch in the Indo-Pacific, has been shown to have extraordinary cryptic diversity and mimicry, and has recently radiated, ultimately complicating species delimitation. In these cases, additional genome-wide data can help improve phylogenetic resolution and provide important insights about evolutionary history. Here, we employ a transcriptome-based exon capture approach to resolve Chromodoris phylogeny with data from 2,925 exons and 1,630 genes, derived from 15 nudibranch transcriptomes. We show that some previously identified mimics instead show mitonuclear discordance, likely deriving from introgression or mitochondrial capture, but we confirm one “pure” mimic in Western Australia. Sister–species relationships and species-level entities were recovered with high support in both concatenated maximum likelihood (ML) and summary coalescent phylogenies, but the ML topologies were highly variable while the coalescent topologies were consistent across datasets. Our work also demonstrates the broad phylogenetic utility of 149 genes that were previously identified from eupulmonate gastropods. This study is one of the first to (a) demonstrate the efficacy of exon capture for recovering relationships among recently radiated invertebrate taxa, (b) employ genome-wide nuclear markers to test mimicry hypotheses in nudibranchs and (c) provide evidence for introgression and mitochondrial capture in nudibranchs.

The Near East and the Caucasus are commonly regarded as the original domestication centres of Vitis vinifera (grapevine), and the region continues to be home to a high diversity of wild and cultivated grapevines, particularly within Georgia. The earliest chemical evidence for wine making was recorded in Georgian Neolithic sites (6000–5800 bc) and grape pips, possibly of the domesticated morphotype, have been reported from several sites of about the same period. We performed geometric morphometric and palaeogenomic investigations of grape pip samples in order to identify the appearance of domesticated grapevine and explore the changes in cultivated diversity in relation to modern varieties. We systematically investigated charred and uncharred grape pip samples from Georgian archaeological sites. Their chronology was thoroughly assessed by direct radiocarbon dating. More than 500 grape pips from 14 sites from the Middle Bronze Age to modern times were selected for geometric morphometric studies. The shapes of the ancient pips were compared to hundreds of modern wild individuals and cultivated varieties. Degraded DNA was isolated from three pips from two sites, converted to Illumina libraries, sequenced at approximately 10,000 single nucleotide polymorphism (SNP) sites, and compared to a large public database of grapevine diversity. The most ancient pip dates from the Middle Bronze Age (1900–1500 cal bc) and the domesticated morphotype is identified from ca. 1000 bc onwards. A great diversity of domesticated shapes was regularly seen in the samples. Most are close to modern cultivars from the Caucasian, southwest Asian and Balkan areas, which suggests that the modern local vine diversity is deeply rooted in early viticulture. DNA was successfully recovered from historic pips and genome-wide analyses found close parental relationships to modern Georgian cultivars.

Building an artificial cell is a research area that is rigorously studied in the field of synthetic biology. It has brought about much attention with the aim of ultimately constructing a natural cell-like structure. In particular, with the more mature cell-free platforms and various compartmentalization methods becoming available, achieving this aim seems not far away. In this review, we discuss the various types of artificial cells capable of hosting several cellular functions. Different compartmental boundaries and the mature and evolving technologies that are used for compartmentalization are examined, and exciting recent advances that overcome or have the potential to address current challenges are discussed. Ultimately, we show how compartmentalization and cell-free systems have, and will, come together to fulfill the goal to assemble a fully synthetic cell that displays functionality and complexity as advanced as that in nature. The development of such artificial cell systems will offer insight into the fundamental study of evolutionary biology and the sea of applications as a result. Although several challenges remain, emerging technologies such as artificial intelligence also appear to help pave the way to address them and achieve the ultimate goal.

Plague continued to afflict Europe for more than five centuries after the Black Death. Yet, by the 17th century, the dynamics of plague had changed, leading to its slow decline in Western Europe over the subsequent 200 y, a period for which only one genome was previously available. Using a multidisciplinary approach, combining genomic and historical data, we assembled Y. pestis genomes from nine individuals covering four Eurasian sites and placed them into an historical context within the established phylogeny. CHE1 (Chechnya, Russia, 18th century) is now the latest Second Plague Pandemic genome and the first non-European sample in the post-Black Death lineage. Its placement in the phylogeny and our synthesis point toward the existence of an extra-European reservoir feeding plague into Western Europe in multiple waves. By considering socioeconomic, ecological, and climatic factors we highlight the importance of a noneurocentric approach for the discussion on Second Plague Pandemic dynamics in Europe.

Replacement of local crops with alternative varieties adapted to future conditions may improve food security under climate change. Here the authors apply landscape genomics and ensemble climate modelling to pearl millet in West Africa, supporting the potential of transfrontier assisted seed exchange.

Summary

Background

The degree of protective immunity conferred by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is currently unknown. As such, the possibility of reinfection with SARS-CoV-2 is not well understood. We describe an investigation of two instances of SARS-CoV-2 infection in the same individual.

Methods

A 25-year-old man who was a resident of Washoe County in the US state of Nevada presented to health authorities on two occasions with symptoms of viral infection, once at a community testing event in April, 2020, and a second time to primary care then hospital at the end of May and beginning of June, 2020. Nasopharyngeal swabs were obtained from the patient at each presentation and twice during follow-up. Nucleic acid amplification testing was done to confirm SARS-CoV-2 infection. We did next-generation sequencing of SARS-CoV-2 extracted from nasopharyngeal swabs. Sequence data were assessed by two different bioinformatic methodologies. A short tandem repeat marker was used for fragment analysis to confirm that samples from both infections came from the same individual.

Findings

The patient had two positive tests for SARS-CoV-2, the first on April 18, 2020, and the second on June 5, 2020, separated by two negative tests done during follow-up in May, 2020. Genomic analysis of SARS-CoV-2 showed genetically significant differences between each variant associated with each instance of infection. The second infection was symptomatically more severe than the first.

Interpretation

Genetic discordance of the two SARS-CoV-2 specimens was greater than could be accounted for by short-term in vivo evolution. These findings suggest that the patient was infected by SARS-CoV-2 on two separate occasions by a genetically distinct virus. Thus, previous exposure to SARS-CoV-2 might not guarantee total immunity in all cases. All individuals, whether previously diagnosed with COVID-19 or not, should take identical precautions to avoid infection with SARS-CoV-2. The implications of reinfections could be relevant for vaccine development and application.

Funding

Nevada IDEA Network of Biomedical Research, and the National Institute of General Medical Sciences (National Institutes of Health).

Takabuti, was a female who lived in ancient Egypt during the 25th Dynasty, c.660 BCE. Her mummified remains were brought to Belfast, Northern Ireland, in 1834 and are currently displayed in the Ulster Museum. To gain insight into Takabuti’s ancestry, we used deep sampling of vertebral bone, under X-ray control, to obtain non-contaminated bone tissue from which we extracted ancient DNA (aDNA) using established protocols. We targeted the maternally inherited mitochondrial DNA (mtDNA), known to be highly informative for human ancestry, and identified 38 single nucleotide variants using next generation sequencing. The specific combination of these SNVs suggests that Takabuti belonged to mitochondrial haplogroup H4a1. Neither H4 nor H4a1 have been reported in ancient Egyptian samples, prior to this study. The modern distribution of H4a1 is rare and sporadic and has been identified in areas including the Canary Islands, southern Iberia and the Lebanon. H4a1 has also been reported in ancient samples from Bell Beaker and Unetice contexts in Germany, as well as Bronze Age Bulgaria. We believe that this is an important finding because first, it adds to the depth of knowledge about the distribution of the H4a1 haplogroup in existing mtDNA, thus creating a baseline for future occurrences of this haplogroup in ancient Egyptian remains. Second, it is of great importance for archaeological sciences, since a predominantly European haplogroup has been identified in an Egyptian individual in Southern Egypt, prior to the Roman and Greek influx (332BCE).

CRISPR guide RNAs (gRNAs) can be programmed with relative ease to allow the genetic editing of nearly any DNA or RNA sequence. Here, we propose novel molecular architectures to achieve RNA-dependent modulation of CRISPR activity in response to specific RNA molecules. We designed and tested, in both living Escherichia coli cells and cell-free assays for rapid prototyping, cis-repressed RNA-interacting guide RNA (igRNA) that switch to their active state only upon interaction with small RNA fragments or long RNA transcripts, including pathogen-derived mRNAs of medical relevance such as the human immunodeficiency virus infectivity factor. The proposed CRISPR-igRNAs are fully customizable and easily adaptable to the majority if not all the available CRISPR-Cas variants to modulate a variety of genetic functions in response to specific cellular conditions, providing orthogonal activation and increased specificity. We thereby foresee a large scope of application for therapeutic, diagnostic, and biotech applications in both prokaryotic and eukaryotic systems.