scholarly journals Strong Genetic Differentiation Between North American and European Populations of Phytophthora alni subsp. uniformis

2013 ◽  
Vol 103 (2) ◽  
pp. 190-199 ◽  
Author(s):  
Jaime Aguayo ◽  
Gerard C. Adams ◽  
Fabien Halkett ◽  
Mursel Catal ◽  
Claude Husson ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
North America ◽  
Mating System ◽  
North American ◽  
Parental Species ◽  
European Countries ◽  
North American Population ◽  
Natural Ecosystems ◽  
Reproduction Mode ◽  
The North

Alder decline caused by Phytophthora alni has been one of the most important diseases of natural ecosystems in Europe during the last 20 years. The emergence of P. alni subsp. alni —the pathogen responsible for the epidemic—is linked to an interspecific hybridization event between two parental species: P. alni subsp. multiformis and P. alni subsp. uniformis. One of the parental species, P. alni subsp. uniformis, has been isolated in several European countries and, recently, in North America. The objective of this work was to assess the level of genetic diversity, the population genetic structure, and the putative reproduction mode and mating system of P. alni subsp. uniformis. Five new polymorphic microsatellite markers were used to contrast both geographical populations. The study comprised 71 isolates of P. alni subsp. uniformis collected from eight European countries and 10 locations in North America. Our results revealed strong differences between continental populations (Fst = 0.88; Rst = 0.74), with no evidence for gene flow. European isolates showed extremely low genetic diversity compared with the North American collection. Selfing appears to be the predominant mating system in both continental collections. The results suggest that the European P. alni subsp. uniformis population is most likely alien and derives from the introduction of a few individuals, whereas the North American population probably is an indigenous population.

scholarly journals Phylogenetics of a Fungal Invasion: Origins and Widespread Dispersal of White-Nose Syndrome

mBio ◽  
2017 ◽  
Vol 8 (6) ◽  
Author(s):  
Kevin P. Drees ◽  
Jeffrey M. Lorch ◽  
Sebastien J. Puechmaille ◽  
Katy L. Parise ◽  
Gudrun Wibbelt ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
North America ◽  
North American ◽  
Fungal Pathogen ◽  
Phylogenetic Study ◽  
Pseudogymnoascus Destructans ◽  
Long Distance ◽  
Recent Introduction ◽  
White Nose Syndrome ◽  
The North

ABSTRACT Globalization has facilitated the worldwide movement and introduction of pathogens, but epizoological reconstructions of these invasions are often hindered by limited sampling and insufficient genetic resolution among isolates. Pseudogymnoascus destructans , a fungal pathogen causing the epizootic of white-nose syndrome in North American bats, has exhibited few genetic polymorphisms in previous studies, presenting challenges for both epizoological tracking of the spread of this fungus and for determining its evolutionary history. We used single nucleotide polymorphisms (SNPs) from whole-genome sequencing and microsatellites to construct high-resolution phylogenies of P. destructans . Shallow genetic diversity and the lack of geographic structuring among North American isolates support a recent introduction followed by expansion via clonal reproduction across the epizootic zone. Moreover, the genetic relationships of isolates within North America suggest widespread mixing and long-distance movement of the fungus. Genetic diversity among isolates of P. destructans from Europe was substantially higher than in those from North America. However, genetic distance between the North American isolates and any given European isolate was similar to the distance between the individual European isolates. In contrast, the isolates we examined from Asia were highly divergent from both European and North American isolates. Although the definitive source for introduction of the North American population has not been conclusively identified, our data support the origin of the North American invasion by P. destructans from Europe rather than Asia. IMPORTANCE This phylogenetic study of the bat white-nose syndrome agent, P. destructans , uses genomics to elucidate evolutionary relationships among populations of the fungal pathogen to understand the epizoology of this biological invasion. We analyze hypervariable and abundant genetic characters (microsatellites and genomic SNPs, respectively) to reveal previously uncharacterized diversity among populations of the pathogen from North America and Eurasia. We present new evidence supporting recent introduction of the fungus to North America from a diverse Eurasian population, with limited increase in genetic variation in North America since that introduction.

Incidence of SCN-Assoicated Gene Mutations in Severe Congenital Neutropenia Patients in North America

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3553-3553
Author(s):  
Jun Xia ◽  
Audrey Anna Bolyard ◽  
Elin Rodger ◽  
Steven Stein ◽  
Andrew AG Aprikyan ◽  
...  
Keyword(s):  
North America ◽  
North American ◽  
Barth Syndrome ◽  
North American Population ◽  
Compound Heterozygous ◽  
Severe Congenital Neutropenia ◽  
Congenital Neutropenia ◽  
Cyclic Neutropenia ◽  
The North ◽  
Two Samples

Abstract Severe congenital neutropenia is a genetically heterogeneous syndrome associated with mutations in several different genes including ELA2, HAX1, GFI1, WAS, and CSF3R. The goal of this study was to define the mutation frequency of these genes in the North American SCN patient population. We also sequenced SBDS, since mutations of SBDS have been associated with congenital and acquired neutropenia. A total of 159 patients were identified in the North American Severe Chronic Neutropenia International Registry (SCNIR) for whom informed consent and genomic DNA samples adequate for sequencing were available. To accommodate our semi-automated high-throughput sequencing pipeline, 94 samples were chosen for sequencing. Since ELA2 sequencing had already been performed in most cases, preference was given to those samples without known ELA2 mutation. Among the samples, 73 were from patients with SCN, 4 with cyclic neutropenia, 10 with idiopathic neutropenia, 2 with Shwachman-Diamond Syndrome (SDS), and 3 with Barth syndrome. Two samples were excluded because of poor sequence quality. Singleton cases with validated mutations of GFI1 (N382S) and WAS (L270P) were observed. The N382S GFI1 mutation was associated with striking monocytosis. A novel nonsense mutation of GFI1 (R412X) was detected in one additional case. As expected, compound heterozygous mutations of SBDS were present in the two cases of SDS. In addition, heterozygous mutations of SBDS (84Cfs3X and Q94X) were observed in two cases of SCN. Typical truncation mutations of CSF3R were detected in 4 cases, all developing MDS or AML. Surprisingly, no mutations of HAX1 were detected. Considering only patients with a diagnosis of SCN who were from North America (125 of the total 159 cases), the incidence of ELA2 mutations was 68%. Eleven novel ELA2 mutations were identified. In 28.8% of cases, no mutation of any gene were detected. Based on these data, we recommend that ELA2 genotyping be performed in all patients with suspected SCN. In the North American population mutations in HAX1, GFI1, SBDS, and WAS are rare and routine genotyping is not indicated. Finally, the data suggest that there are yet undiscovered genetic causes of SCN.

scholarly journals Fungus Causing White-Nose Syndrome in Bats Accumulates Genetic Variability in North America with No Sign of Recombination

mSphere ◽  
2017 ◽  
Vol 2 (4) ◽  
Author(s):  
Jigar Trivedi ◽  
Josianne Lachapelle ◽  
Karen J. Vanderwolf ◽  
Vikram Misra ◽  
Craig K. R. Willis ◽  
...  
Keyword(s):  
North America ◽  
North American ◽  
Disease Ecology ◽  
Spontaneous Mutation ◽  
North American Population ◽  
Pseudogymnoascus Destructans ◽  
Clonal Population ◽  
White Nose Syndrome ◽  
The North ◽  
Single Clone

ABSTRACT Emerging fungal diseases of wildlife are on the rise worldwide, and the white-nose syndrome (WNS) epidemic in North American bats is a catastrophic example. The causal agent of WNS is a single clone of the fungus Pseudogymnoascus destructans. Early evolutionary change in this clonal population has major implications for disease ecology and conservation. Accumulation of variation in the fungus through mutation, and shuffling of variation through recombination, could affect the virulence and transmissibility of the fungus and the durability of what appears to be resistance arising in some bat populations. Our genome-wide analysis shows that the clonal population of P. destructans has expanded in size from a single genotype, has begun to accumulate variation through mutation, and presents no evidence as yet of genetic exchange among individuals. IMPORTANCE Since its discovery in 2006, the emerging infectious disease known as white-nose syndrome has killed millions of bats in North America, making it one of the most devastating wildlife epidemics in recorded history. We demonstrate that there has been as yet only spontaneous mutation across the North American population of P. destructans, and we find no indication of recombination. Thus, selective forces, which might otherwise impact pathogenic virulence, have so far had essentially no genetic variation on which to act. Our study confirmed the time of origin for the first and, thus far, only introduction of P. destructans to North America. This system provides an unprecedented opportunity to follow the evolution of a host-pathogen interaction unfolding in real time.

scholarly journals Genetic diversity of rhizobia nodulating Trifolium ambiguum in North America

2001 ◽  
Vol 47 (1) ◽  
pp. 81-85 ◽  
Author(s):  
P Seguin ◽  
P H Graham ◽  
C C Sheaffer ◽  
N J Ehlke ◽  
M P Russelle
Keyword(s):  
Genetic Diversity ◽  
North America ◽  
North American ◽  
Diversity Index ◽  
Diversity Indices ◽  
Clustering Methods ◽  
Center Of Origin ◽  
Trifolium Ambiguum ◽  
Kura Clover ◽  
The North

Kura clover (Trifolium ambiguum M.B.) is a persistent rhizomatous forage legume, whose use in the U.S.A. is limited by establishment difficulties in part attributable to nodulation problems. In this study, soil was collected from established stands of Kura clover growing in 9 diverse North American environments. Rhizobia were plant-trapped using Kura clover cv. Endura as host, then rhizobia from nodules fingerprinted using BOX-PCR. The diversity of isolates from North America was then contrasted to that of rhizobia from a single Caucasian environment (Russia), the center of origin for this species. Populations were characterized using clustering methods, and genetic diversity estimated using the Shannon-Weaver diversity index. The genetic diversity of the North American populations was extremely limited, all isolates being closely related to two of the strains found in a locally available commercial inoculant. In contrast, Russian isolates formed a distinct cluster with significant internal genetic diversity. Genetic diversity indices for the North American and Russian populations were 3.5 and 10.76, respectively. The implication of this and other studies is that Kura clover is highly specific in Rhizobium requirement. If the performance of this legume in the U.S.A. is to be improved, either by modifying current establishment practices or plant breeding, it is essential that these studies be paralleled by more collections and evaluation of rhizobia from its center of origin, given the extremely limited diversity of rhizobia found in North America.Key words: genetic diversity, rhizobia, Kura clover, BOX-PCR.

scholarly journals Population Genomic Analyses Reveal Connectivity via Human-Mediated Transport across Populus Plantations in North America and an Undescribed Subpopulation of Sphaerulina musiva

2020 ◽  
Vol 33 (2) ◽  
pp. 189-199 ◽  
Author(s):  
J. F. Tabima ◽  
K. L. Søndreli ◽  
S. Keriö ◽  
N. Feau ◽  
M. L. Sakalidis ◽  
...  
Keyword(s):  
United States ◽  
British Columbia ◽  
North America ◽  
North American ◽  
Plant Pathogens ◽  
Evolutionary Dynamics ◽  
Population Genomics ◽  
Plant Domestication ◽  
North American Population ◽  
The North

Domestication of plant species has affected the evolutionary dynamics of plant pathogens in agriculture and forestry. A model system for studying the consequences of plant domestication on the evolution of an emergent plant disease is the fungal pathogen Sphaerulina musiva. This ascomycete causes leaf spot and stem canker disease of Populus spp. and their hybrids. A population genomics approach was used to determine the degree of population structure and evidence for selection on the North American population of S. musiva. In total, 122 samples of the fungus were genotyped identifying 120,016 single-nucleotide polymorphisms after quality filtering. In North America, S. musiva has low to moderate degrees of differentiation among locations. Three main genetic clusters were detected: southeastern United States, midwestern United States and Canada, and a new British Columbia cluster (BC2). Population genomics suggest that BC2 is a novel genetic cluster from central British Columbia, clearly differentiated from previously reported S. musiva from coastal British Columbia, and the product of a single migration event. Phenotypic measurements from greenhouse experiments indicate lower aggressiveness of BC2 on Populus trichocarpa. In summary, S. musiva has geographic structure across broad regions indicative of gene flow among clusters. The interconnectedness of the North American S. musiva populations across large geographic distances further supports the hypothesis of anthropogenic-facilitated transport of the pathogen.

scholarly journals Progress in Diagnosing Primary Ciliary Dyskinesia: The North American Perspective

Diagnostics ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1278
Author(s):  
Michael Glenn O’Connor ◽  
Amjad Horani ◽  
Adam J. Shapiro
Keyword(s):  
Genetic Testing ◽  
North America ◽  
North American ◽  
Primary Ciliary Dyskinesia ◽  
Clinical Phenotype ◽  
The United States ◽  
Diagnostic Process ◽  
The North ◽  
Diagnostic Guideline ◽  
Ciliary Dyskinesia

Primary Ciliary Dyskinesia (PCD) is a rare, under-recognized disease that affects respiratory ciliary function, resulting in chronic oto-sino-pulmonary disease. The PCD clinical phenotype overlaps with other common respiratory conditions and no single diagnostic test detects all forms of PCD. In 2018, PCD experts collaborated with the American Thoracic Society (ATS) to create a clinical diagnostic guideline for patients across North America, specifically considering the local resources and limitations for PCD diagnosis in the United States and Canada. Nasal nitric oxide (nNO) testing is recommended for first-line testing in patients ≥5 years old with a compatible clinical phenotype; however, all low nNO values require confirmation with genetic testing or ciliary electron micrograph (EM) analysis. Furthermore, these guidelines recognize that not all North American patients have access to nNO testing and isolated genetic testing is appropriate in cases with strong clinical PCD phenotypes. For unresolved diagnostic cases, referral to a PCD Foundation accredited center is recommended. The purpose of this narrative review is to provide insight on the North American PCD diagnostic process, to enhance the understanding of and adherence to current guidelines, and to promote collaboration with diagnostic pathways used outside of North America.

New multituberculate mammal from the Early Cretaceous of eastern North America

2013 ◽  
Vol 50 (3) ◽  
pp. 315-323 ◽  
Author(s):  
Richard L. Cifelli ◽  
Cynthia L. Gordon ◽  
Thomas R. Lipka
Keyword(s):  
North America ◽  
Iberian Peninsula ◽  
Early Cretaceous ◽  
North American ◽  
Lower Cretaceous ◽  
Late Jurassic ◽  
Relative Length ◽  
Central Position ◽  
Eastern North America ◽  
The North

Multituberculates, though among the most commonly encountered mammalian fossils of the Mesozoic, are poorly known from the North American Early Cretaceous, with only one taxon named to date. Herein we describe Argillomys marylandensis, gen. et sp. nov., from the Early Cretaceous of Maryland, based on an isolated M2. Argillomys represents the second mammal known from the Arundel Clay facies of the Patuxent Formation (Lower Cretaceous: Aptian). Though distinctive in its combination of characters (e.g., enamel ornamentation consisting of ribs and grooves only, cusp formula 2:4, presence of distinct cusp on anterobuccal ridge, enlargement of second cusp on buccal row, central position of ultimate cusp in lingual row, great relative length), the broader affinities of Argillomys cannot be established because of non-representation of the antemolar dentition. Based on lack of apomorphies commonly seen among Cimolodonta (e.g., three or more cusps present in buccal row, fusion of cusps in lingual row, cusps strongly pyramidal and separated by narrow grooves), we provisionally regard Argillomys as a multituberculate of “plagiaulacidan” grade. Intriguingly, it is comparable in certain respects to some unnamed Paulchoffatiidae, a family otherwise known from the Late Jurassic – Early Cretaceous of the Iberian Peninsula.

A Kinematic Reconstruction of Jurassic ocean spreading from the ophiolites of California, the western U.S. using structural geology and paleomagnetism.

2021 ◽  
Author(s):  
Cemil Arkula ◽  
Nalan Lom ◽  
John Wakabayashi ◽  
Grant Rea-Downing ◽  
Mark Dekkers ◽  
...  
Keyword(s):  
North America ◽  
Relative Position ◽  
North American ◽  
Fault System ◽  
Paleomagnetic Data ◽  
Geochemical Data ◽  
Ophiolite Belt ◽  
The North ◽  
Western Us ◽  
Jurassic Ophiolites

<p>The western edge of the North America plate contains geological records that formed during the long-lived convergence between plates of the Panthalassa Ocean and North America. The geology of different segments along western North America indicates different polarities (eastward and westward) for subducted slabs and thereby various tectonic histories and settings. The western United States (together with Mexico) plays a key role in this debate, many geologic interpretations assume continuous eastward subduction in contrast to observations within proximal geologic segments and tomographic images of the lower mantle below North America and the eastern Pacific Ocean which suggest a more complex subduction history. In this study, we aim to evaluate the plate tectonic setting in which the Jurassic ophiolites of California formed. Geochemical data from these ophiolites suggest that they formed above a nascent intra-oceanic or continental margin subduction zone. We first developed a kinematic reconstruction of the western US geology back to the Jurassic based on published structural geological data. Importantly, we update the reconstruction of the various branches of the San Andreas fault system to determine the relative position of the ophiolite fragments and adopt a previous restoration of Basin and Range extension which we expand northward towards Washington state. We then reconstruct North American margin deformation associated with Cretaceous to Paleogene shortening and strike-slip faulting. We find no clear candidates in the geological record that may have accommodated major subduction between the Jurassic ophiolite belt and the North American margin and consequently concur with the school of thought that considers that the ophiolite belt, as well as the underlying subduction-accretionary Franciscan Complex, likely formed in the North American fore-arc. We collected paleomagnetic data to reconstruct the spreading direction of the Jurassic Californian ophiolites, by providing new paleomagnetic data from sheeted dykes of the Josephine and Mt. Diablo Ophiolites. These suggest a NE-SW paleo-ridge orientation, oblique to the North American margin which may be explained by partitioning of a dextral component of subduction obliquity relative to North America. We used this spreading direction in combination with published ages of the ophiolites and our restoration of the relative position of these ophiolites prior to post-Jurassic deformation to construct a ridge-transform system at which the Jurassic ophiolites accreted. The results will be used to evaluate which parts of the subduction systems that existed in the eastern Panthalassa Ocean may reside in the western US, and which parts may be better sought in the northern Canadian Segment or/and in the southern Caribbean region.</p>

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