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Salmonella enterica serovar Abortusovis is a host-restricted pathogen of sheep that causes invasive disease and spontaneous abortion (1-3). Transmission is thought to be limited to sheep; however, early studies identified [...]

Introduction Use of psychoactive substances constitutes a significant and growing international health concern. More than 4% of the global burden of disease and injury is attributable to substance use, and [...], Lifetime and temporal co-occurrence of substance use disorders (SUDs) is common and compared with individual SUDs is characterized by greater severity, additional psychiatric comorbidities, and worse outcomes. Here, we review evidence for the role of generalized genetic liability to various SUDs. Coaggregation of SUDs has familial contributions, with twin studies suggesting a strong contribution of additive genetic influences undergirding use disorders for a variety of substances (including alcohol, nicotine, cannabis, and others). GWAS have documented similarly large genetic correlations between alcohol, cannabis, and opioid use disorders. Extending these findings, recent studies have identified multiple genomic loci that contribute to common risk for these SUDs and problematic tobacco use, implicating dopaminergic regulatory and neuronal development mechanisms in the pathophysiology of generalized SUD genetic liability, with certain signals demonstrating cross-species and translational validity. Overlap with genetic signals for other externalizing behaviors, while substantial, does not explain the entirety of the generalized genetic signal for SUD. Polygenic scores (PGS) derived from the generalized genetic liability to SUDs outperform PGS for individual SUDs in prediction of serious mental health and medical comorbidities. Going forward, it will be important to further elucidate the etiology of generalized SUD genetic liability by incorporating additional SUDs, evaluating clinical presentation across the lifespan, and increasing the granularity of investigation (e.g., specific transdiagnostic criteria) to ultimately improve the nosology, prevention, and treatment of SUDs.

It is often assumed that the northern peripheral populations of species' ranges are genetically depauperate due in part to founder effects from postglacial colonization. The majority of federally protected plant species are peripheral in Canada, yet we have little information about their patterns of genetic diversity and structure. In British Columbia, the majority of these protected plant species occur in two threatened habitats: the Garry oak and Okanagan shrub-steppe ecosystems. Using universal noncoding chloroplast DNA markers, we investigated genetic diversity and genetic structure in four rare and common plant species pairs inhabiting these two ecosystems. We found that rare species had lower genetic diversity than their common congeners, and detected contrasting patterns of regional diversity and structure based on ecosystem. Species from the Garry oak ecosystem showed lower genetic diversity in the northern deglaciated region and significant differentiation between regions, likely due to limited dispersal between Vancouver Island and the mainland. Species from the Okanagan shrub-steppe, however, tended to have uniform diversity across their range and lack regional structure. This study provides an important first look at the phylogeographic patterns of four rare plant species in British Columbia. Key words: conservation genetics, British Columbia, rare plants, chloroplast DNA, phylogeography, genetic diversity, Garry oak ecosystem, shrub-steppe ecosystem, Introduction Genetic diversity is critical to the long-term viability of wild plant and animal species (Frankham 1996; Hughes et al. 2008) and is considered a prerequisite for adaptation to changing [...]

The giant barrel sponges (Xestospongia spp.) belong to a pan-global species complex with evidence suggesting they could encompass up to 9 cryptic species. In this study, we leveraged molecular and microbial techniques to investigate giant barrel sponges (X. testudinaria) from Singapore in relation to their placement within this species complex. Twenty-four giant barrel sponges from three sites were sequenced with mitochondrial (CO1) and nuclear (ATP6) DNA markers, identifying 6 distinct haplotypes belonging to 4 of the proposed barrel sponge species. Analysis of the X. testudinaria microbiomes was achieved with 16S rRNA gene amplicon sequencing. The microbiome composition of X. testudinaria did not differ by reef site, deviating from a pattern frequently observed in coral microbiomes across Singapore. However, there was significant differentiation in microbiome composition by host genetics consistent with the proposed species boundaries. General linear models identified 85 amplicon sequence variants (ASVs) as highly significant (P < 0.01) in differentiating among the four Species Groups, consisting of 12 Archaea and 73 Bacteria, with the largest representation from phylum Chloroflexi. We also identified 52 core ASVs present in all sponges representing 33.0% of the total sequence reads. Our results support previous findings of microbiome differentiation in co-occurring genetic haplotypes of barrel sponges from the Caribbean. Together these studies underline the potential for ecological partitioning based on genetic haplotype that could contribute to cryptic speciation within the giant barrel sponge species complex., Author(s): Lindsey K. Deignan [sup.1] , Raiyan Dansson [sup.1] , Aaron An Rong Loh [sup.1] , Keay Hoon Pwa [sup.1] Author Affiliations: (1) grid.484638.5, 0000 0004 7703 9448, Singapore Centre [...]

The tropical eastern Pacific (TEP) has been divided into several biogeographic provinces separated by two types of habitat gaps: stretches of sandy shoreline that separate rocky reefs on the mainland (Sinaloan and Central American gaps) and expanses of deep ocean between offshore TEP islands and the mainland. Those gaps are known to influence the distribution and evolution of TEP reef fishes by acting as barriers to gene flow. We investigated potential effects of those gaps on the genetic structure and connectivity of populations of five widely distributed TEP reef-fish species that have different modes of life, habitat preferences and reproductive strategies: Caranx caballus, Rypticus bicolor, Hypsoblennius brevipinnis, Plagiotremus azaleus and Stegastes flavilatus. We used the coxI mitochondrial DNA marker to make phylogeographic, population genetics, and coalescent analyses of geographic patterns of genetic variation in these species. Those analyses showed high variation in levels of genetic diversity. We found no geographic genetic differentiation relating to mainland gaps in any species. Such genetic homogeneity may relate to factors such as migratory behavior, high pelagic dispersal potential and wide environmental tolerance. In two species, differentiation across oceanic gaps separating oceanic islands from the mainland may reflect differences between insular and mainland environments. Historical population expansions that occurred between 400 and 100 thousand years ago in different species may have shaped by patterns of Pleistocene climatic dynamics. The lack of polymorphism of coxI in the damselfish Stegastes flavilatus may relate to the effects of a historical population collapse, although we were not able to detect that genetically., Author(s): Paola N. Palmerín-Serrano [sup.1] , Victor J. Piñeros [sup.1] [sup.2] [sup.3] , D. Ross Robertson [sup.4] , Arturo Angulo [sup.5] , Eduardo Espinoza [sup.6] , Enrique Barraza [sup.7] , [...]

We used microsatellite genetic markers to evaluate the mating system of western red cedar (Thuja plicata Donn ex D. Don) under various seed orchard pollen management schemes. We primarily examined whether supplemental mass pollination (SMP) can reduce the observed selfing rates. Pollen blowing and 'hooding' were also examined in smaller tests. Only SMP was consistently effective in reducing the selfing rate, from 30% to 20%. The correlation of paternity was quite high (60%-90%) in two of three orchards, and in these two orchards the application of SMP reduced this correlation by about 10% as well. The correlation of paternity is the fraction of full-sibling vs. half-sibling progeny, and unbiased estimates can be obtained with few loci, even single loci, in contrast to other types of paternity analysis. We also find the microsatellite amplicon sizes should be pooled into 'bins' of 2-4 nucleotides, owing to unintended errors of assay; otherwise the estimates are biased. This new feature of mating system estimation was incorporated into the computer program MLTR. Key words: self-fertilization, correlated paternity, supplemental mass pollination, western red cedar. Les auteurs ont utilisé des marqueurs génétiques microsatellites afin d'évaluer le système de fécondation du thuya géant (Thuja plicata Donn ex D. Don) dans le cadre de divers programmes de gestion du pollen de vergers à graines. Ils ont d'abord examiné si une pollinisation de masse supplémentaire (PMS) peut réduire les taux d'autofécondation observés. Le soufflage et le << capuchonnage >> (<< hooding >>) du pollen ont aussi été examinés lors de tests à plus petite échelle. Seule la PMS était efficace de façon constante pour réduire le taux d'autofécondation de 30% à 20%. La corrélation de la paternité était relativement élevée (60-90%) dans deux des trois vergers et dans ces deux vergers, l'application de la PMS réduisait aussi cette corrélation d'environ 10%. La corrélation de la paternité consiste en la fraction de pleins germains par rapport à la demi-fratrie dans la progéniture, et des estimations non biaisées peuvent être obtenues avec peu de locus, et même un seul locus, comparativement aux autres types d'analyse de paternité. Les auteurs ont aussi constaté que les tailles des amplicons microsatellites devraient être regroupées en << classes >> (bins) de 2-4 nucléotides, en raison d'erreurs involontaires du test; sinon, les estimations sont biaisées. Cette nouvelle caractéristique du système de fécondation a été incorporée au programme informatique MLTR. [Traduit par la Rédaction] Mots-clés : autofécondation, paternité corrélée, pollinisation de masse supplémentaire, thuya géant., Introduction Seed orchards connect the generations between domesticated trees and deliver genetically improved trees to natural populations. In British Columbia, there are seed orchards for two species of angiosperms and [...]

African swine fever (ASF) is one of the most pathogenic viral diseases of swine leading to clinical and pathomorphological signs of a viral hemorrhagic fever (1). In 2007, ASF was [...]

Author(s): Mohamed Abbas[sup.1], Nadia Gaïa[sup.2], Nicolas C. Buchs[sup.3], Vaihere Delaune[sup.3], Myriam Girard[sup.2], Diego O. Andrey[sup.4], Jeremy Meyer[sup.3], Jacques Schrenzel[sup.2,4,5], Frédéric Ris[sup.3], Stephan Harbarth[sup.1,4] and Vladimir Lazarevic[sup.2] Introduction Surgical site infections [...], Background Colon surgery has been shown to modulate the intestinal microbiota. Our objective was to characterize these changes using state-of-the-art next generation sequencing techniques. Methods We performed a single-centre prospective observational cohort study to evaluate the changes in the gut microbiota, i.e., taxon distribution, before and after elective oncologic colon surgery in adult patients with different antimicrobial prophylaxis regimens (standard prophylaxis with cefuroxime/metronidazole versus carbapenems for extended-spectrum beta-lactamase-producing Enterobacterales [ESBL-E] carriers). We obtained rectal samples on the day of surgery, intraoperative luminal samples, and rectal or stoma samples 3 days after surgery. We performed metataxonomic analysis based on sequencing of the bacterial 16S rRNA gene marker. Similarities and differences between bacterial communities were assessed using Bray-Curtis similarity, visualised using principal coordinates analysis and statistically tested by PERMANOVA. Comparison of taxa relative abundance was performed using ANCOM. Results We included 27 patients between March 27, 2019 and September 17, 2019. The median age was 63.6 years (IQR 56.4-76.3) and 44% were females. Most (81%) patients received standard perioperative prophylaxis as they were not ESBL carriers. There was no significant association between ESBL carriage and differences in gut microbiome. We observed large and significant increases in the genus Enterococcus between the preoperative/intraoperative samples and the postoperative sample, mainly driven by Enterococcus faecalis. There were significant differences in the postoperative microbiome between patients who received standard prophylaxis and carbapenems, specifically in the family Erysipelotrichaceae. Conclusion This hypothesis-generating study showed rapid changes in the rectal microbiota following colon cancer surgery. Keywords: Gut microbiome, Colon cancer, Colon surgery, Antimicrobial prophylaxis