scholarly journals A Novel and Divergent Gyrovirus with Unusual Genomic Features Detected in Wild Passerine Birds from a Remote Rainforest in French Guiana

Viruses ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1148 ◽  
Author(s):  
Daniel A. Truchado ◽  
José Manuel Diaz-Piqueras ◽  
Esperanza Gomez-Lucia ◽  
Ana Doménech ◽  
Borja Milá ◽  
...  

Sequence-independent amplification techniques have become important tools for virus discovery, metagenomics, and exploration of viral diversity at the global scale, especially in remote areas. Here, we describe the detection and genetic characterization of a novel gyrovirus, named GyV11, present in cloacal, oral, and blood samples from neotropical wild birds in French Guiana. The molecular epidemiology revealed the presence of GyV11 only in passerine birds from three different species at a low prevalence (0.73%). This is the first characterization and prevalence study of a gyrovirus carried out in resident wild bird populations in a remote region, and provides evidence of the fecal–oral route transmission and local circulation of the virus. The molecular phylogeny of gyroviruses reveals the existence of two distinct gyrovirus lineages in which GyV11 is phylogenetically distinct from previously reported gyroviruses. Furthermore, GyV11 is placed basal in the gyrovirus phylogeny, likely owing to its ancestral origin and marked divergence. This study also provides important insights into the ecology, epidemiology, and genomic features of gyroviruses in a remote neotropical rainforest. The pathogenesis of this virus in avian species or whether GyV11 can infect humans and/or chickens needs to be further investigated.

2021 ◽  
Vol 10 (6) ◽  
pp. 384
Author(s):  
Javier Martínez-López ◽  
Bastian Bertzky ◽  
Simon Willcock ◽  
Marine Robuchon ◽  
María Almagro ◽  
...  

Protected areas (PAs) are a key strategy to reverse global biodiversity declines, but they are under increasing pressure from anthropogenic activities and concomitant effects. Thus, the heterogeneous landscapes within PAs, containing a number of different habitats and ecosystem types, are in various degrees of disturbance. Characterizing habitats and ecosystems within the global protected area network requires large-scale monitoring over long time scales. This study reviews methods for the biophysical characterization of terrestrial PAs at a global scale by means of remote sensing (RS) and provides further recommendations. To this end, we first discuss the importance of taking into account the structural and functional attributes, as well as integrating a broad spectrum of variables, to account for the different ecosystem and habitat types within PAs, considering examples at local and regional scales. We then discuss potential variables, challenges and limitations of existing global environmental stratifications, as well as the biophysical characterization of PAs, and finally offer some recommendations. Computational and interoperability issues are also discussed, as well as the potential of cloud-based platforms linked to earth observations to support large-scale characterization of PAs. Using RS to characterize PAs globally is a crucial approach to help ensure sustainable development, but it requires further work before such studies are able to inform large-scale conservation actions. This study proposes 14 recommendations in order to improve existing initiatives to biophysically characterize PAs at a global scale.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Chantriolnt-Andreas Kapourani ◽  
Ricard Argelaguet ◽  
Guido Sanguinetti ◽  
Catalina A. Vallejos

AbstractHigh-throughput single-cell measurements of DNA methylomes can quantify methylation heterogeneity and uncover its role in gene regulation. However, technical limitations and sparse coverage can preclude this task. scMET is a hierarchical Bayesian model which overcomes sparsity, sharing information across cells and genomic features to robustly quantify genuine biological heterogeneity. scMET can identify highly variable features that drive epigenetic heterogeneity, and perform differential methylation and variability analyses. We illustrate how scMET facilitates the characterization of epigenetically distinct cell populations and how it enables the formulation of novel hypotheses on the epigenetic regulation of gene expression. scMET is available at https://github.com/andreaskapou/scMET.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Amy Gaye ◽  
Tolla Ndiaye ◽  
Mouhamad Sy ◽  
Awa B. Deme ◽  
Alphonse B. Thiaw ◽  
...  

AbstractDengue virus is a major and rapidly growing public health concern in tropic and subtropic regions across the globe. In late 2018, Senegal experienced its largest dengue virus outbreak to date, covering several regions. However, little is known about the genetic diversity of dengue virus (DENV) in Senegal. Here we report complete viral genomes from 17 previously undetected DENV cases from the city of Thiès. In total we identified 19 cases of DENV in a cohort of 198 individuals with fever collected in October and November 2018. We detected 3 co-circulating serotypes; DENV 3 was the most frequent accounting for 11/17 sequences (65%), 4 (23%) were DENV2 and 2 (12%) were DENV1. Sequences were most similar to recent sequences from West Africa, suggesting ongoing local circulation of viral populations; however, detailed inference is limited by the scarcity of available genomic data. We did not find clear associations with reported clinical signs or symptoms, highlighting the importance of testing for diagnosing febrile diseases. Overall, these findings expand the known range of DENV in Senegal, and underscore the need for better genomic characterization of DENV in West Africa.


Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 725
Author(s):  
Fernando Clavijo-Coppens ◽  
Nicolas Ginet ◽  
Sophie Cesbron ◽  
Martial Briand ◽  
Marie-Agnès Jacques ◽  
...  

Xylella fastidiosa (Xf) is a plant pathogen causing significant losses in agriculture worldwide. Originating from America, this bacterium caused recent epidemics in southern Europe and is thus considered an emerging pathogen. As the European regulations do not authorize antibiotic treatment in plants, alternative treatments are urgently needed to control the spread of the pathogen and eventually to cure infected crops. One such alternative is the use of phage therapy, developed more than 100 years ago to cure human dysentery and nowadays adapted to agriculture. The first step towards phage therapy is the isolation of the appropriate bacteriophages. With this goal, we searched for phages able to infect Xf strains that are endemic in the Mediterranean area. However, as Xf is truly a fastidious organism, we chose the phylogenetically closest and relatively fast-growing organism X. albineans as a surrogate host for the isolation step. Our results showed the isolation from various sources and preliminary characterization of several phages active on different Xf strains, namely, from the fastidiosa (Xff), multiplex (Xfm), and pauca (Xfp) subspecies, as well as on X. albilineans. We sequenced their genomes, described their genomic features, and provided a phylogeny analysis that allowed us to propose new taxonomic elements. Among the 14 genomes sequenced, we could identify two new phage species, belonging to two new genera of the Caudoviricetes order, namely, Usmevirus (Podoviridae family) and Subavirus (Siphoviridae family). Interestingly, no specific phages could be isolated from infected plant samples, whereas one was isolated from vector insects captured in a contaminated area, and several from surface and sewage waters from the Marseille area.


2020 ◽  
Vol 29 (7) ◽  
pp. 1230-1245 ◽  
Author(s):  
Paulo N. Bernardino ◽  
Wanda De Keersmaecker ◽  
Rasmus Fensholt ◽  
Jan Verbesselt ◽  
Ben Somers ◽  
...  

2014 ◽  
Vol 81 (1) ◽  
pp. 166-176 ◽  
Author(s):  
Francesca Bottacini ◽  
Mary O'Connell Motherway ◽  
Eoghan Casey ◽  
Brian McDonnell ◽  
Jennifer Mahony ◽  
...  

ABSTRACTBifidobacterium breveis a common and sometimes very abundant inhabitant of the human gut. Genome sequencing ofB. breveJCM 7017 revealed the presence of an extrachromosomal element, designated pMP7017 consisting of >190 kb, thus representing the first reported bifidobacterial megaplasmid.In silicocharacterization of this element revealed several genomic features supporting a stable establishment of the megaplasmid in its host, illustrated by predicted CRISPR-Cas functions that are known to protect the host against intrusion of foreign DNA. Interestingly, pMP7017 is also predicted to encode a conjugative DNA transfer apparatus and, consistent with this notion, we demonstrate here the conjugal transfer of pMP7017 to representative strains ofB. breveandB. longumsubsp.longum. We also demonstrate the presence of a megaplasmid with homology to pMP7017 in threeB. longumsubsp.longumstrains.


2003 ◽  
Vol 19 (2) ◽  
pp. 209-214 ◽  
Author(s):  
Jean-François Mauffrey ◽  
François Catzeflis

Stable isotopes are commonly used in ecological studies to infer food resources (Ambrose & DeNiro 1986, Bocherens et al. 1990,1991,1994;Yoshinaga et al. 1991) since isotopic composition is conserved during the feeding process. Moreover,for herbivorous (sensu lato) species, it is often possible to identify the main resource because different photosynthetic pathways generate different values of carbon isotope ratios (Park & Epstein 1961, Sternberg et al. 1984). This allows the characterization of broad biota such as savannas or forest and discrimination of grazers from sympatric folivorous species (DeNiro & Epstein 1978).


2012 ◽  
Vol 21 (1) ◽  
pp. 7-15 ◽  
Author(s):  
Fabiane Sebaio ◽  
Érika Martins Braga ◽  
Felipe Branquinho ◽  
Alan Fecchio ◽  
Miguel Ângelo Marini

Parasites may lead bird species to extinction, affect host temporal and spatial population dynamics, alter community structure and alter individuals’ social status. We evaluated blood parasite prevalence and intensity according to bird families and species, among 925 birds that were caught in 2000 and 2001, in the Atlantic Forest in the State of Minas Gerais, Brazil. We applied Giemsa staining to thin blood smears, to detect blood parasites. The birds (n = 15.8%) in 11 families, were infected by at least one parasite genus, especially Muscicapidae (28.3%) and Conopophagidae (25%). Among the 146 infected birds, Plasmodium was detected in all bird families and had the highest prevalence (54.8%). Trypanosoma, Haemoproteus and microfilaria had lower prevalence rates (23.3, 23.3 and 2.1%, respectively). Birds caught during the rainy season were more infected than birds caught during the dry season. The overall low prevalence of blood parasites in birds is similar to the patterns found elsewhere in the Neotropical region.


2019 ◽  
Author(s):  
Micah N. Scholer ◽  
Matt Strimas-Mackey ◽  
Jill E. Jankowski

AbstractTropical birds are purported to be longer lived than temperate species of similar size, but it has not been shown whether avian survival rates covary with a latitudinal gradient worldwide. Here, we perform a global-scale meta-analysis to investigate the extent of the latitudinal survival gradient. We modeled survival as a function of latitude for the separate northern and southern hemispheres, and considered phylogenetic relationships and extrinsic (climate) and intrinsic (life history) predictors hypothesized to moderate these effects. Using a database of 1,004 estimates from 246 studies of avian survival, we demonstrate that in general a latitudinal survival gradient exists in the northern hemisphere, is dampened or absent for southern hemisphere species, and that survival rates of passerine birds largely account for these trends. We found no indication that the extrinsic climate factors were better predictors of survival than latitude alone, but including species’ intrinsic traits improved model predictions. Notably, species with smaller clutch size and larger body mass showed higher survival. Our results illustrate that while some tropical birds may be longer lived than their temperate counterparts, the shape of the latitude-survival gradient differs by geographic region and is strongly influenced by species’ intrinsic traits.


Grana ◽  
2022 ◽  
pp. 1-43
Author(s):  
Adriana Mercedes Camejo Aviles ◽  
Marie-Pierre Ledru ◽  
Fresia Ricardi-Branco ◽  
Paula A. Rodríguez-Zorro ◽  
Ricardo J. Francischetti Garcia ◽  
...  

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