Evolutionary Applications最新文献

Recent studies highlight extensive crosstalk that exists between sensory neurons responsible for pain and the immune system. Cutaneous pain neurons detect harmful microbes, recruit immune cells, and produce anticipatory immunity in nearby tissues. These complementary systems generally protect hosts from infections. At the same time, neuroimmune pain is vulnerable to manipulation. Some pathogens evade immunity activated by nociceptors by producing opioid analogs and by interfering with sensory nerve function. Other organisms manipulate neuroimmune pain by increasing it. Hosts may gain protection from interference by adjusting pain sensitivity. Nociceptive sensitization follows expectations of signal detection theory and the smoke detector principle, allowing pain to be more easily triggered in response to microbial threats and damage. However, pain sensitization at the spinal level and cortical responses to pain are themselves the target of manipulation by parasites and other organisms. Here we review examples of parasites, bacteria, and other medically important organisms that interfere with pain signaling and describe their implications for public health, infectious disease, and the treatment of pain.

Landscape ecology and genetics provide important analytical frameworks for investigating the effect of environmental features on ecological processes. Few empirical studies, however, have simultaneously tested how landscape characteristics influence spatial patterns of gene flow and abundance of pest insects in heterogeneous environments. To address this, we undertook a combined landscape-ecology/landscape-genetic study of the tephritid fruit fly, Bactrocera tryoni , in the Wide Bay-Burnett region of Southeast Queensland, Australia. This region contains areas of rainforest, Eucalyptus forest, cleared pasture, residential areas, and two areas of intensive horticulture production; one implementing area-wide management practices. We collected B. tryoni samples from 26 sites in 2021 during the months of April, August, October, December and the following year during February and April. We used high-density DArTseq SNP genotyping on samples collected during the 2021 April, August and December sampling periods. We then modelled the contemporary landscape characteristics and management factors influencing gene flow and abundance of this pest species. Genome-wide SNP analysis estimated infinite effective population sizes at all sites and detected limited genetic structure across the landscape. However, fly abundance varied significantly among habitats, with cleared pasture negatively associated with population abundance and acting as a barrier to gene flow. Additionally, highways in composite with cleared pasture exhibited a very strong barrier effect. Abundance was highest in residential areas and rainforest, lowest in Eucalyptus forest, and reduced in the horticultural region with area-wide management implemented. We discuss the benefits of collecting simultaneous genetic and ecological datasets for informing and evaluating area-wide management programmes for insect pests and highlight considerations in the spatial analysis of SNP data when effective population sizes are extremely large.

Ectothermic vertebrates with genotypic sex determination may adjust their sexual phenotype to early-life environmental conditions by sex reversal, and theoretical models predict diverse consequences for population dynamics and microevolution under environmental change. Environments that frequently expose individuals to sex-reversing effects may select for or against the propensity to undergo sex reversal, depending on the relative fitness of sex-reversed individuals. Yet, empirical data on the adaptive value and evolutionary potential of sex reversal is scarce. Here we conducted a common-garden experiment with agile frogs (Rana dalmatina) that respond to larval heat stress by sex reversal, to test whether sex-reversal propensity has changed via microevolution in populations that live in anthropogenic habitats where potentially sex-reversing heat events are more frequent, compared to populations that live in cooler woodland habitats. Furthermore, to infer the adaptive value of sex reversal, we compared fitness-related traits between heat-exposed genotypic females that phenotypically developed into males (sex-reversed) or females (sex-concordant). We found that the frequency of sex reversal varied between sibgroups and was higher in the sibgroups originating from anthropogenic habitats, regardless of the thermal environment they had been exposed to during the larval sex-determination period. Among heat-exposed animals, time to metamorphosis was similar between sex-reversed individuals and sex-concordant females, but the former reached larger body mass by the end of the experiment than the latter, approaching the mass of sex-concordant males. These results suggest that sex-reversal propensity may have increased in anthropogenic environments by adaptive microevolution, potentially to minimize the fitness cost of reduced growth caused by heat events. Thus, environmental sex reversal has the potential to provide an adaptive strategy for ectothermic vertebrates to cope with challenges of the Anthropocene. Such knowledge on the causes and consequences of sex reversal will help pinpoint which populations are most threatened by extinction due to climatically influenced sex determination.

Contagious cancers represent one of the least understood types of infections in wildlife. Devil Facial Tumor Disease (comprised of two different contagious cancers, DFT1 and DFT2) has led to an 80% decline in the Tasmanian devil (Sarcophilus harrisii ) population at the regional level since it was first observed in 1996. There are currently no treatment options for the disease, and research efforts are focused on vaccine development. Although DFT1 is clonal, phylogenomic studies have identified different genetic variants of the pathogen. We postulated that different genetic strains may have different gene expression profiles and would therefore require different vaccine components. Here, we aimed to test this hypothesis by applying two types of unsupervised clustering (hierarchical and k-means) to 35 DFT1 transcriptomes selected from the disease's four major phylogenetic clades. The two algorithms produced conflicting results, and there was low support for either method individually. Validation metrics, such as the Gap statistic method, the Elbow method, and the Silhouette method, were ambiguous, contradictory, or indicated that our dataset only consisted of a single cluster. Collectively, our results show that the different phylogenetic clades of DFT1 all have similar gene expression profiles. Previous studies have suggested that transcriptomic differences exist between tumours from different locations. However, our study differs in that it considers both tumor purity and genotypic clade when analysing differences between DFTD biopsies. These results have important implications for therapeutic development, as they indicate that a single vaccine or treatment approach has the potential to be effective for a large cross-section of DFT1 tumors. As one of the largest studies to use transcriptomics to investigate phenotypic variation within a single contagious cancer, it also provides novel insight into this unique group of diseases.

The European sardine (Sardina pilchardus) sustains some of the most important East Atlantic fisheries and is exhibiting pronounced phenotypic and distributional changes linked to environmental changes. The application of high-resolution genomic methods is recommended to provide insights into population demographics and patterns of ecological and evolutionary diversification. This study performed genome wide SNP analysis of samples collected across understudied NE Atlantic waters as well as geographical outgroup samples from Morocco and the Western Mediterranean. The data revealed pronounced differentiation of three regional groups (NE Atlantic, Morocco, and Western Mediterranean) that can be linked to glacial vicariance and contemporary dispersal limitations. Structuring was also apparent at outlier loci adding to evidence that genome architecture and non-neutral processes are influencing sardine populations at various spatial scales. The highly resolved Morocco group may be a previously undescribed and localized lineage and confirms complex stock structure along the North African coast. Among the NE Atlantic samples, genome wide patterns confirm restricted gene flow between Biscay and North Sea sardine with signatures of isolation by distance. F_ST, individual assignment, and introgression tail analyses of outlier loci revealed further structuring and identify a North Sea—Eastern Channel group distinct from a Bay of Biscay-Celtic Sea-Western Channel group. This pattern contradicts current management boundaries and indicates that increasing sardine numbers in the North Sea reflect an expansion of an eastern English Channel-North Sea fringe population. While this confirms the ability of the species' northern peripheral populations to expand in response to changing conditions, the genetically differentiated southern populations may differ in this regard. Overall, this study adds to a developing genetic framework for understanding sardine biocomplexity and provides resources for management.

Tree species are often locally adapted to their environments, but the extent to which environmental adaptation contributes to incipient speciation is unclear. One of the rarest pines in the world, Torrey pine (Pinus torreyana Parry), persists naturally across one island and one mainland population in southern California. The two populations are morphologically and genetically differentiated but experience some connectivity, making it an ideal system for assessing the evolution of reproductive isolation. Previous work has found evidence of heterosis in F1 mainland-island hybrids, suggesting genetic rescue could be beneficial in the absence of reproductive barriers. Using ddRADseq and GWAS for a common garden experiment of island, mainland, and F1 individuals, we identified candidate loci for environmentally driven reproductive isolation, their function, and their relationship to fitness proxies. By simulating neutral evolution and admixture between the two populations, we identified loci that exhibited reduced heterozygosity in the F1s, evidence of selection against admixture. SNPs with reduced F1 heterozygosity were enriched for growth and pollination functions, suggesting genetic variants that could be involved in the evolution of reproductive barriers between populations. One locus with reduced F1 heterozygosity exhibited strong associations with growth and reproductive fitness proxies in the common garden, with the mainland allele conferring increased fitness. If this locus experiences divergent selection in the two natural populations, it could promote their reproductive isolation. Finally, although hybridization largely reduced allele fixation in the F1s initially, indicating heterosis is likely due to the masking of deleterious alleles, the emergence of reproductive isolation between populations may diminish the longer-term benefits of genetic rescue in F2 or advanced-generation hybrids. As Torrey pine is a candidate for interpopulation genetic rescue, caution is warranted where longer-term gene flow between diverged populations may result in reduced fitness if barriers have evolved.

Stocks of the European flat oyster, Ostrea edulis, have collapsed due to overfishing, habitat destruction, and pathogen outbreaks across most of their distribution range. Nonetheless, as a result of lower exploitation pressure and the absence of pathogens in the most northern part of the range, a large part of the remaining wild population can be found in relatively high densities in Scandinavia, a region in Northern Europe. However, despite recent studies focusing on flat oyster population structure along the European coast, little is known about the population structure of oysters in the Skagerrak marginal sea in Scandinavia, and how it is related to neighbouring regions. This study, therefore, aimed to investigate the population structure of flat oysters in Scandinavia, with a special emphasis on the Skagerrak. We gathered low-coverage whole-genome sequencing data from oysters in Sweden, Norway, and Denmark, the three countries that border the Skagerrak. Genetic diversity appeared to be homogeneously distributed over the sampled area in the Skagerrak, while samples collected from the east coast of Denmark and from a location with known historical farming activity on the Norwegian West Coast were genetically distinct from Skagerrak samples. A genetic barrier analysis indicated barriers to gene flow in the Baltic Sea transition zone and on the west coast of Norway. Overall, our results suggest that flat oysters from the Swedish Skagerrak coasts form a single panmictic population that is distinct from neighbouring seas, potentially allowing for regional management of stocks and restoration translocations in the area. However, the genetic composition of donor and recipient stocks should be assessed on a case-by-case basis, genetic diversity effects of hatchery practices should be monitored, and biosecurity measures need to be considered prior to any movement of stock.

The genetic structure and demographic history of marine organisms are shaped by a variety of factors including biological and ecological characteristics, ocean currents, and the palaeogeological effects of sea-level fluctuations. Here we present a comprehensive method combining population genomics, laboratory experiments, and ocean modelling in 13 populations of the chiton Acanthochitona rubrolineata along the coast of China. Based on demographic and population genomic analyses, significant divergence was observed between the Northern and Southern population groups, which are separated by the Yangtze River Estuary. The numerical circulation model simulation showed that gene flow and population connectivity were strongly influenced by ocean currents and the larval dispersal ability of chiton A. rubrolineata. These data thus clearly revealed the presence of two separately evolving lineages in chiton—A. rubrolineata northern and A. rubrolineata southern. Our study highlights that a robust understanding of organisms in the intertidal zone requires a comprehensive consideration of factors that influence gene flow and genetic structure, including the life-history traits, coastal currents, geographic isolation, and habitat suitability. The life history of marine organisms, together with local oceanographic features, could ultimately drive the population divergence and lead to speciation. These findings provide a guideline for future analyses of non-model and potentially threatened species and will aid in the conservation of biodiversity.

The symposium “Evolutionary Applications” took place on June 28, 2024 in the virtual part of the 3rd Joint Congress on Evolutionary Biology. It was contributed to the conference by the European Society for Evolutionary Biology (ESEB). The symposium highlighted research on evolutionary biology applied to address questions and contemporary problems in medicine and public health, conservation biology, and food production and agriculture. Each of the six talks covered a different application and a different organism: domestication of cheese-making fungi, restoration of long-lived bird populations, evolution of herbicide resistance, coral reef conservation, gene drive systems targeting Malaria vectors, and antibiotic resistance evolution in bacteria. By including speakers who are active in a consortium or work in an NGO, the symposium also showed how to make the step from scientific findings to practical application. The symposium furthermore featured a range of scientific methods, ranging from genomic analyses and mathematical modeling to laboratory evolution and field experiments. Speakers from across 15 time zones highlighted the potential of virtual symposia to foster global collaboration in evolutionary biology.

Restoring connectivity via assisted migration is a useful but currently underused approach for maintaining genetic diversity and preventing extirpations of threatened species. The use of assisted migration as a conservation strategy may be limited by the difficulty of balancing the benefits of reconnecting populations (including reduced inbreeding depression and increased adaptive capacity) with the perceived risk of outbreeding depression, which requires comprehensive knowledge of the landscape of adaptive, neutral, deleterious, and structural variation across a species' range. Using a combination of reduced-representation and whole-genome sequencing, we characterized genomic diversity and differentiation for the Arkansas Darter (Etheostoma cragini) across its range in the Midwestern US. We found strong population structure and large differences in genetic diversity and effective population sizes across drainages. The strength of genetic isolation by river distance differed among drainages, with landscape type surrounding streams and impoundments also contributing to genetic isolation. Despite low effective population sizes in some populations, there was surprisingly little evidence for recent inbreeding (based on the absence of long runs of homozygosity) or for elevated levels of deleterious variation in smaller populations. Considering neutral, adaptive, deleterious, and structural variation allowed us to identify several potential recipient populations that may benefit from translocations and potential donor sites throughout the range. Planning translocation strategies intended for restored connectivity and possible genetic rescue at earlier stages in species decline will likely increase the probability of retaining genetic diversity and population persistence over the long term while minimizing risks associated with translocation.