15 research outputs found

    The draft genome sequence of the spider Dysdera silvatica (Araneae, Dysderidae): A valuable resource for functional and evolutionary genomic studies in chelicerates

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    Background We present the draft genome sequence of Dysdera silvatica, a nocturnal ground-dwelling spider from a genus that has undergone a remarkable adaptive radiation in the Canary Islands. Results The draft assembly was obtained using short (Illumina) and long (PaciBio and Nanopore) sequencing reads. Our de novo assembly (1.36 Gb), which represents 80% of the genome size estimated by flow cytometry (1.7 Gb), is constituted by a high fraction of interspersed repetitive elements (53.8%). The assembly completeness, using BUSCO and core eukaryotic genes, ranges from 90% to 96%. Functional annotations based on both ab initio and evidence-based information (including D. silvatica RNA sequencing) yielded a total of 48,619 protein-coding sequences, of which 36,398 (74.9%) have the molecular hallmark of known protein domains, or sequence similarity with Swiss-Prot sequences. The D. silvatica assembly is the first representative of the superfamily Dysderoidea, and just the second available genome of Synspermiata, one of the major evolutionary lineages of the 'true spiders' (Araneomorphae). Conclusions Dysderoids, which are known for their numerous instances of adaptation to underground environments, include some of the few examples of trophic specialization within spiders and are excellent models for the study of cryptic female choice. This resource will be therefore useful as a starting point to study fundamental evolutionary and functional questions, including the molecular bases of the adaptation to extreme environments and ecological shifts, as well of the origin and evolution of relevant spider traits, such as the venom and silk

    The Genome Sequence of the Grape Phylloxera Provides Insights into the Evolution, Adaptation, and Invasion Routes of an Iconic Pest

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    Background: Although native to North America, the invasion of the aphid-like grape phylloxera Daktulosphaira vitifoliae across the globe altered the course of grape cultivation. For the past 150 years, viticulture relied on grafting-resistant North American Vitis species as rootstocks, thereby limiting genetic stocks tolerant to other stressors such as pathogens and climate change. Limited understanding of the insect genetics resulted in successive outbreaks across the globe when rootstocks failed. Here we report the 294-Mb genome of D. vitifoliae as a basic tool to understand host plant manipulation, nutritional endosymbiosis, and enhance global viticulture. Results: Using a combination of genome, RNA, and population resequencing, we found grape phylloxera showed high duplication rates since its common ancestor with aphids, but similarity in most metabolic genes, despite lacking obligate nutritional symbioses and feeding from parenchyma. Similarly, no enrichment occurred in development genes in relation to viviparity. However, phylloxera evolved > 2700 unique genes that resemble putative effectors and are active during feeding. Population sequencing revealed the global invasion began from the upper Mississippi River in North America, spread to Europe and from there to the rest of the world. Conclusions: The grape phylloxera genome reveals genetic architecture relative to the evolution of nutritional endosymbiosis, viviparity, and herbivory. The extraordinary expansion in effector genes also suggests novel adaptations to plant feeding and how insects induce complex plant phenotypes, for instance galls. Finally, our understanding of the origin of this invasive species and its genome provide genetics resources to alleviate rootstock bottlenecks restricting the advancement of viticulture

    Research Priorities to Support Effective Manta and Devil Ray Conservation

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    Manta and devil rays are filter-feeding elasmobranchs that are found circumglobally in tropical and subtropical waters. Although relatively understudied for most of the Twentieth century, public awareness and scientific research on these species has increased dramatically in recent years. Much of this attention has been in response to targeted fisheries, international trade in mobulid products, and a growing concern over the fate of exploited populations. Despite progress in mobulid research, major knowledge gaps still exist, hindering the development of effective management and conservation strategies. We assembled 30 leaders and emerging experts in the fields of mobulid biology, ecology, and conservation to identify pressing knowledge gaps that must be filled to facilitate improved science-based management of these vulnerable species. We highlight focal research topics in the subject areas of taxonomy and diversity, life history, reproduction and nursery areas, population trends, bycatch and fisheries, spatial dynamics and movements, foraging and diving, pollution and contaminants, and sub-lethal impacts. Mobulid rays remain a poorly studied group, and therefore our list of important knowledge gaps is extensive. However, we hope that this identification of high priority knowledge gaps will stimulate and focus future mobulid research

    Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

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    Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

    Computational prediction of the phenotypic effects of genetic variants: basic concepts and some application examples in Drosophila nervous system genes

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    Predicting the phenotypic impact of mutations is a central challenge in population and functional genetics. The analysis of DNA and amino acid sequence variation in an evolutionary context is a robust approach to infer the fitness effects of genetic variants. In this review, we discuss the most popular methods based on this approach, covering both theoretical and practical aspects, and introduce compelling software for predicting the functional effects of mutations, and to highlight functionally relevant nucleotide or amino acid candidate positions. Furthermore, we provide some examples of their application to Drosophila genes affecting significant aspects of the development, physiology and function of the nervous system.This work was supported by grants of the Ministerio de Economía y Competitividad, Spain (CGL2016–75255), and by the Comissió Interdepartamental de Recerca I Innovació Tecnològica of Catalonia, Spain (2014SGR-1055). SG-R was supported by a Beatriu de Pinós Postdoctoral Fellowship (AGAUR; 2014 BP-B 00027), and SHA by the Consejo Nacional de Ciencia y Tecnología, México.Peer reviewe

    The chloroplast genome of the pincushion cactus Mammilllaria haageana subsp. san-angelensis, a Mexican endangered species

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    The genus Mammillaria occupies diverse habitats and exhibits diverse growth patterns and a large range of morphologies. Most of the species of this genus are used as ornamental plants and are subject to mass habitat loss. Due to these factors, they are being submitted to selective pressure that might affect conservational efforts and management plans. We obtained the 133 gene chloroplast genome as part of the project of sequencing the complete genome of pincushion cactus, including 88 protein-coding genes, 8 rRNA genes, and 37 tRNA genes. The phylogenetic tree indicates the pincushion cactus is a sister species of M. supertexta and M. huitzilopochtli

    Evaluating the monophyly of Mammillaria series Supertextae (Cactaceae)

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    Mammillaria (Cactaceae) taxonomy has been historically problematic due to the morphological variability and sympatry of the species. This has led to several proposals for infrageneric classification, including subgeneric, section and series categories. Mammillaria ser. Supertextae is one of 15 series and is made up of a variable set of species that are mainly distributed in southern Mexico and Central America. However, the phylogenetic relationships within M. ser. Supertextae and its relationship to other Mammillaria taxa are far from fully understood. Here we attempt to elucidate these relationships using complete terminal sampling and newly obtained chloroplast marker sequences and comparing them to Mammillaria species sequences from GenBank. Our phylogenetic analyses showed that M. ser. Supertextae comprises a well-supported monophyletic group that diverged approximately 2.1 Mya and has M. ser. Polyacanthae as its sister group; however, relationships within M. ser. Supertextae remain unresolved. The topology obtained within M. ser. Supertextae must also be interpreted under the distribution shared by these taxa, but it is difficult to differentiate ancestral polymorphisms from possible introgression, given the short time elapsed and the markers used. Our results show that the infrageneric units of M. haageana and M. albilanata can be considered independent evolutionary units. We also suggest that the relationship between M. haageana and M. albilanata is convoluted because their distribution overlaps (mainly towards southern Mexico), with genetic differences that possibly indicate they represent more than two taxonomic entities. One possible explanation is that there could still be gene flow between these taxa, and we might be witnessing an ongoing speciation process

    Supplementation of flavonoids and inulin in Totoaba macdonaldi: Microbiota, liver gene expression and growth performance responses

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    Totoaba macdonaldi is an endemic, vulnerable, carnivorous fish of the Gulf of California that is currently being cultivated in northwestern Mexico for commercial and conservation purposes. The challenge for aquaculture of Totoaba is finding a diet that meets the protein requirements at an acceptable price and does not compromise its overall performance. Current diets in aquaculture are either prejudicial for the environment or have caused adverse effects on the digestive system and liver of Totoaba. To counteract those negative effects, this study evaluates quercetin and epicatechin supplementation in two doses (0.25% and 0.5%), with and without inulin, as functional additives. A total of 360 juveniles were divided into 18 tanks and fed with six experimental diets in triplicate. Growth performance, intestinal microbiota, blood biochemistry, and liver transcriptomics were evaluated. The liver’s transcriptome de novo assembly had an N50 of 2599 bp and 76.38% BUSCO completeness. Experimental diets showed higher growth performance than the control diet (p < 0.05). The lowest concentrations of triglycerides and cholesterol were observed in fish fed with Inulin (I), Flavonoids at 0.5% (FH), and Flavonoids at 0.5% + Inulin (IFH). In the liver, Flavonoids at 0.25% (FL) and IFH diets presented down regulated genes related to metabolic and biosynthetic processes, whereas FH and Inulin diets presented upregulated genes related to cellular and growth processes. Additionally, the FH diet presented a greater abundance of Lactobacillaceae and a reduction of Enterococcus faecalis and Vibrio anguillarum in the intestinal microbiome. The present results found that flavonoids and inulin improve metagenomic diversity at the intestinal level by increasing the abundance of beneficial bacteria. This leads to a reciprocal interaction improving the absorption of flavonoids, reducing fat absorption in the gastrointestinal tract, enhancing gene modulation of metabolic processes involved in lipid oxidation
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