CRISPR-based gene-drives targeting the gene doublesex in the malaria vector Anopheles gambiae effectively suppressed the reproductive capability of mosquito populations reared in small laboratory cages. To bridge the gap between laboratory and the field, this gene-drive technology must be challenged with vector ecology.Here we report the suppressive activity of the gene-drive in age-structured An. gambiae populations in large indoor cages that permit complex feeding and reproductive behaviours.The gene-drive element spreads rapidly through the populations, fully supresses the population within one year and without selecting for resistance to the gene drive. Approximate Bayesian computation allowed retrospective inference of life-history parameters from the large cages and a more accurate prediction of gene-drive behaviour under more ecologically-relevant settings.Generating data to bridge laboratory and field studies for invasive technologies is challenging. Our study represents a paradigm for the stepwise and sound development of vector control tools based on gene-drive.
Biogenic fraction of airborne PM10 which includes bacteria, viruses, fungi and pollens, has been proposed as one of the potential causes of the PM10 toxicity. The present study aimed to provide a comprehensive understanding of the microbial community variations associated to PM10, and their main local sources in the surrounding environment in three urban sites of Rome, characterized by differential pollution rate: green area, residential area and polluted area close to the traffic roads. We combined high-throughput amplicon sequencing of the bacterial 16S rRNA gene and the fungal internal transcribed spacer (ITS) region, with detailed chemical analysis of particulate matter sampled from air, paved road surfaces and leaf surfaces of Quercus ilex. Our results demonstrated that bacterial and fungal airborne communities were characterized by the highest alpha-diversity and grouped separately from epiphytic and road dust communities. The reconstruction of source-sink relationships revealed that the resuspension/deposition of road dust from traffic might contribute to the maximum magnitude of microbial exchanges. The relative abundance of extremotolerant microbes was found to be enhanced in epiphytic communities and was associated to a progressively increase of pollution levels as well as opportunistic human pathogenicity in fungal communities.
A biocultural diversity approach integrates plant biology and germplasm dispersal processes with human cultural diversity. An increasing number of studies have identified cultural factors and ethnolinguistic barriers as the main drivers of the genetic diversity in crop plants. Little is known about how anthropogenic processes have affected the evolution of tree crops over the entire time scale of their interaction with humans. In Asia and the Mediterranean, common walnut (Juglans regia L.) and sweet chestnut (Castanea sativa Mill.) have been economically and culturally important crops for millennia; there, in ancient times, they were invested with symbolic and religious significance. In this study, we detected a partial geographic congruence between the ethno‐linguistic repartition of human communities, the distribution of major cognitive sets of word‐related terms, and the inferred genetic clusters of common walnut and sweet chestnut populations across Eurasia. Our data indicated that isolation by distance processes, landscape heterogeneity and cultural boundaries might have promoted simultaneously human language diversification and walnut/chestnut differentiation across the same geographic macro‐regions. Hotspots of common walnut and sweet chestnut genetic diversity were associated with areas of linguistic enrichment in the Himalayas, Trans‐Caucasus, and Pyrenees Mountains, where common walnuts and sweet chestnuts had sustained ties to human culture since the Early Bronze Age. Our multidisciplinary approach supported the indirect and direct role of humans in shaping walnut and chestnut diversity across Eurasia from the EBA (e.g., Persian Empire and Greek–Roman colonization) until the first evidence of active selection and clonal propagation by grafting of both species. Our findings highlighted the benefit of an efficient integration of the relevant cultural factors in the classical genome (G) × environmental (E) model and the urgency of a systematic application of the biocultural diversity concept in the reconstruction of the evolutionary history of tree species.
Acerola fruit is one of the richest natural sources of ascorbic acid. As a consequence, acerola fruit and its products are in demand worldwide for the production of health supplements and for the development of functional products. Acerola phenotypes (103) were screened in Western Paraná State, in the Southern region of Brazil, and evaluated to obtain information on fruit quality characteristics with the aim of using them in future breeding programs. Principal Component and Hierarchical Cluster analysis were performed on all datasets to explore the variability among samples and to identify the main clusters. A great variability among phenotypes was observed, with potential for use in breeding programs. Seven phenotypes were selected as candidates in the next breeding program, characterized by high vitamin C content and yield, or higher values of fruit size and color parameters. Four belong to cluster 1 and three to cluster 2. Specifically, two phenotypes, belonging to cluster 2, showed the best performance in terms of vitamin C (2150 mg 100 g−1 pulp and 2625 mg 100 g−1 pulp respectively) and pulp yield (74.8% and 82.3% respectively), and one phenotype, belonging to cluster 1, for high pulp yield, fruit size and vitamin C content (80.3% 6.43 g and 2490 mg 100 g−1 pulp).
The development of genetically modified mosquitoes and their subsequent field release offers innovative and cost‐effective approaches to reduce mosquito‐borne diseases, such as malaria. A sex‐distorting autosomal transgene has been developed recently in G3 mosquitoes, a lab strain of the malaria vector Anopheles gambiae s.l. The transgene expresses an endonuclease called I‐PpoI during spermatogenesis, which selectively cleaves the X chromosome to result in ~95% male progeny. Following the World Health Organization guidance framework for the testing of genetically modified mosquitoes, we assessed the dynamics of this transgene in large cages using a joint experimental‐modelling approach. We performed a four‐month experiment in large, indoor cages to study the population genetics of the transgene. The cages were set up to mimic a simple tropical environment with a diurnal light‐cycle, constant temperature, and constant humidity. We allowed the generations to overlap to engender a stable age structure in the populations. We constructed a model to mimic the experiments, and used the experimental data to infer the key model parameters. We identified two fitness costs associated to the transgene. First, transgenic adult males have reduced fertility and, second, their female progeny have reduced pupal survival rates. Our results demonstrate that the transgene is likely to disappear in less than three years under our confined conditions. Model predictions suggest this will be true over a wide range of background population sizes and transgene introduction rates. Synthesis and applications . Our study is in line with World Health Organization guidance recommendations in regards to the development and testing of genetically modified mosquitoes. Since the transgenic sex‐ratio‐distorter strain (Ag(PMB)1) has been considered for genetic vector control of malaria, we recorded the dynamics of this transgene in indoor‐large cage populations and modelled its post‐release persistence under different scenarios. We provide a demonstration of the self‐limiting nature of the transgene, and identified new fitness costs that will be further reduce the longevity of the transgene after its release. Finally, our study has showcased an alternative and effective statistical method for characterising the phenotypic expression of a transgene in an insect pest population.
13 September 2023 in Frontiers in Environmental Science
Introduction: Biogenic fraction of airborne PM10 dominated by bacteria and fungi, has been recognized as serious environmental and human health issues in cities.Methods: In the present study, we combined a high-throughput amplicon sequencing of the bacterial 16S rRNA gene and the fungal internal transcribed spacer (ITS) region, with elemental analysis of airborne particulate matter (PM10) to investigate the community compositions and structures of PM10-associated bacteria and fungi across four different seasons in three urban sites of Rome with differential pollution rate.Results: In this study, а clear seasonal shift of bacterial and fungal community structure driven by PM10 mass concentrations and environmental factors, such as temperature and precipitations, has been identified. In addition, the seasonal impact of local sources and long-range transported air masses on the community structures of the microbes has been also postulated. Our data revealed that the lack of precipitation and the subsequent resuspension of dust produced by vehicular traffic might contribute to the maximum abundance of soil-associated microbes in winter and summer. However, the increase of PM10 concentrations favoured also by climatic conditions, domestic heating and dust advection event from African desert further shaped the community structure of winter. Across three seasons, the pollutant removal-hydrogen oxidation bacteria and the opportunist-human pathogenic fungi progressively increased with pollution levels, in the sequence from green to residential and/or polluted area close to the traffic roads, with highest fraction during winter.Discussion: Hence, our results highlight a close interrelationship between pollution, climatic factors and abundance of certain bacterial and fungal predicted functional groups also with potential implications for human health.