Evidence for genetic hybridization between Ixodes scapularis and Ixodes cookei

2017 ◽  
Vol 95 (8) ◽  
pp. 527-537 ◽  
Author(s):  
James W. Patterson ◽  
Anna M. Duncan ◽  
Kelsey C. McIntyre ◽  
Vett K. Lloyd
Keyword(s):  
Mitochondrial Dna ◽  
Genetic Analysis ◽  
New Brunswick ◽  
Nuclear Dna ◽  
Ixodes Scapularis ◽  
Companion Animals ◽  
Genetic Introgression ◽  
Eastern Canada ◽  
As Species ◽  
Intermediate Traits

Ixodes scapularis Say, 1821 (the black-legged tick) is becoming established in Canada. The northwards expansion of I. scapularis leads to contact between I. scapularis and Ixodes cookei Packard, 1869, a well-established tick species in Eastern Canada. Examination of I. cookei and I. scapularis collected from New Brunswick revealed ticks with ambiguous morphologies, with either a mixture or intermediate traits typical of I. scapularis and I. cookei, including in characteristics typically used as species identifiers. Genetic analysis to determine if these ticks represent hybrids revealed that four had I. cookei derived mitochondrial DNA but I. scapularis nuclear DNA. In one case, the nuclear sequence showed evidence of heterozygosity for I. scapularis and I. cookei sequences, whereas in the others, the nuclear DNA appeared to be entirely derived from I. scapularis. These data strongly suggest genetic hybridization between these two species. Ixodes cookei and hybrid ticks were readily collected from humans and companion animals and specimens infected with Borrelia burgdorferi Johnson et al., 1984, the causative agent of Lyme disease, were identified. These findings raise the issue of genetic introgression of I. scapularis genes into I. cookei and warrant reassessment of the capacity of I. cookei and I. cookei × I. scapularis hybrids to vector Borrelia infection.

Mitochondrial DNA and the phylogeography of Newfoundland black bears

1996 ◽  
Vol 74 (1) ◽  
pp. 192-196 ◽  
Author(s):  
David Paetkau ◽  
Curtis Strobeck
Keyword(s):  
Genetic Diversity ◽  
Mitochondrial Dna ◽  
New Brunswick ◽  
Ursus Americanus ◽  
Sequence Data ◽  
Black Bears ◽  
Glacial Refugium ◽  
Eastern Canada ◽  
Postglacial Colonization ◽  
Dna Molecule

The degree of genetic differentiation separating Newfoundland black bears (Ursus americanus hamiltoni) from continental Canadian black bears (U. a. americanus and U. a. cinnamomum) was assessed using sequence data from part of the mitochondrial DNA molecule. All of the individuals from insular Newfoundland, New Brunswick, and Quebec, and most of the individuals from Alberta, had very closely related haplotypes. Haplotypes from Newfoundland animals were more similar to those in eastern Canada than the eastern Canadian lineages were to related lineages in Alberta black bears. Given the previous observation of reduced genetic diversity in Newfoundland black bears, this subspecies likely arose through rapid genetic drift associated with a founder effect during postglacial colonization of the island, and not through long periods of isolation in a glacial refugium.

scholarly journals Hybridization between different lineages of pidschian-like whitefishes (Coregonus lavaretus pidschian, coregonidae) in water bodies of Southern Siberia

2017 ◽  
Vol 15 (2) ◽  
pp. 31-43
Author(s):  
Nikolai A Bochkarev ◽  
Elena I Zuykova ◽  
Michail M Solovyov
Keyword(s):  
Mitochondrial Dna ◽  
Genetic Analysis ◽  
Morphological Analysis ◽  
Nuclear Dna ◽  
Branchial Arch ◽  
Water Bodies ◽  
Coregonus Lavaretus ◽  
Southern Siberia ◽  
Gill Raker

Background. The purpose of this work was studying of interaction between morphologically similar forms of the pidcshian-like whitefishes inhabiting restricted territory of “riverine-lacustrine” system situated in the Bolshoi Abakan Rriver basin. Material and methods. In the morphological analysis were used 141 whitefish individuals from Lake Karakul and 26 - from the Bolshoi Abakan River. In the genetic analysis 11 and 26 whitefish individuals were used respectively. For them the sequences of a gene 16S-ND1 of mitochondrial DNA (mtDNA) and ITS1 of nuclear DNA (nDNA) were defined. Results. The whitefish populations clear differ on the gill raker numbers on the first branchial arch, growth. The analysis of the 16S-ND1 mtDNA genes variability revealed among them several divergent lineages and two lineages were revealed on the structure of ITS1 fragment of the nDNA. Conclusions. Based on the obtained data it is proved that two genetically divergent populations of the morphologically same forms of pidcshian-like whitefishes inhabiting the “riverine-lacustrine” system (the Bolshoi Abakan River - Lake Karakul). Our results are supported a hypothesis of multiple hybridization between week differentiated populations/form of pidcshian-like whitefishes inhabiting region during the postglacial period.

scholarly journals Monitoring the patterns of submission and presence of tick-borne pathogens in Ixodes scapularis collected from humans and companion animals in Ontario, Canada (2011–2017)

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Mark P. Nelder ◽  
Curtis B. Russell ◽  
Antonia Dibernardo ◽  
Katie M. Clow ◽  
Steven Johnson ◽  
...  
Keyword(s):  
Borrelia Burgdorferi ◽  
Regression Models ◽  
Ixodes Scapularis ◽  
Companion Animals ◽  
Companion Animal ◽  
Babesia Microti ◽  
Blacklegged Tick ◽  
Host Type ◽  
Animal Populations ◽  
Pathogen Prevalence

Abstract Background The universal nature of the human–companion animal relationship and their shared ticks and tick-borne pathogens offers an opportunity for improving public and veterinary health surveillance. With this in mind, we describe the spatiotemporal trends for blacklegged tick (Ixodes scapularis) submissions from humans and companion animals in Ontario, along with pathogen prevalence. Methods We tested tick samples submitted through passive surveillance (2011–2017) from humans and companion animals for Borrelia burgdorferi, Borrelia miyamotoi, Anaplasma phagocytophilum and Babesia microti. We describe pathogen prevalence in ticks from humans and from companion animals and constructed univariable Poisson and negative binomial regression models to explore the spatiotemporal relationship between the rates of tick submissions by host type. Results During the study, there were 17,230 blacklegged tick samples submitted from humans and 4375 from companion animals. Tick submission rates from companion animals were higher than expected in several public health units (PHUs) lacking established tick populations, potentially indicating newly emerging populations. Pathogen prevalence in ticks was higher in PHUs where established blacklegged tick populations exist. Borrelia burgdorferi prevalence was higher in ticks collected from humans (maximum likelihood estimate, MLE = 17.5%; 95% confidence interval, CI 16.97–18.09%) than from companion animals (9.9%, 95% CI 9.15–10.78%). There was no difference in pathogen prevalence in ticks by host type for the remaining pathogens, which were found in less than 1% of tested ticks. The most common co-infection B. burgdorferi + B. miyamotoi occurred in 0.11% of blacklegged ticks from humans and animals combined. Borrelia burgdorferi prevalence was higher in unengorged (21.9%, 95% CI 21.12–22.65%) than engorged ticks (10.0%, 95% CI 9.45–10.56%). There were no consistent and significant spatiotemporal relationships detected via regression models between the annual rates of submission of each host type. Conclusions While B. burgdorferi has been present in blacklegged ticks in Ontario for several decades, other tick-borne pathogens are also present at low prevalence. Blacklegged tick and pathogen surveillance data can be used to monitor risk in human and companion animal populations, and efforts are under consideration to unite surveillance efforts for the different target populations. Graphic Abstract

scholarly journals The Role of Mitochondria in Carcinogenesis

2021 ◽  
Vol 22 (10) ◽  
pp. 5100
Author(s):  
Paulina Kozakiewicz ◽  
Ludmiła Grzybowska-Szatkowska ◽  
Marzanna Ciesielka ◽  
Jolanta Rzymowska
Keyword(s):  
Prostate Cancer ◽  
Mitochondrial Dna ◽  
Nuclear Dna ◽  
Dna Polymorphisms ◽  
Gene Encoding ◽  
Dna Mutations ◽  
Nadh Ubiquinone Oxidoreductase ◽  
Gene Coi ◽  
The Impact

The mitochondria are essential for normal cell functioning. Changes in mitochondrial DNA (mtDNA) may affect the occurrence of some chronic diseases and cancer. This process is complex and not entirely understood. The assignment to a particular mitochondrial haplogroup may be a factor that either contributes to cancer development or reduces its likelihood. Mutations in mtDNA occurring via an increase in reactive oxygen species may favour the occurrence of further changes both in mitochondrial and nuclear DNA. Mitochondrial DNA mutations in postmitotic cells are not inherited, but may play a role both in initiation and progression of cancer. One of the first discovered polymorphisms associated with cancer was in the gene NADH-ubiquinone oxidoreductase chain 3 (mt-ND3) and it was typical of haplogroup N. In prostate cancer, these mutations and polymorphisms involve a gene encoding subunit I of respiratory complex IV cytochrome c oxidase subunit 1 gene (COI). At present, a growing number of studies also address the impact of mtDNA polymorphisms on prognosis in cancer patients. Some of the mitochondrial DNA polymorphisms occur in both chronic disease and cancer, for instance polymorphism G5913A characteristic of prostate cancer and hypertension.

scholarly journals Mitochondrial DNA Heteroplasmy as an Informational Reservoir Dynamically Linked to Metabolic and Immunological Processes Associated with COVID-19 Neurological Disorders

2021 ◽  
Author(s):  
George B. Stefano ◽  
Richard M. Kream
Keyword(s):  
Mitochondrial Dna ◽  
Mitochondrial Function ◽  
Neurological Disorders ◽  
Nuclear Dna ◽  
Mitochondrial Dynamics ◽  
Cell Types ◽  
Tissue Specific ◽  
Copy Numbers ◽  
The Central Nervous System ◽  
Mitochondrial Dna Heteroplasmy

AbstractMitochondrial DNA (mtDNA) heteroplasmy is the dynamically determined co-expression of wild type (WT) inherited polymorphisms and collective time-dependent somatic mutations within individual mtDNA genomes. The temporal expression and distribution of cell-specific and tissue-specific mtDNA heteroplasmy in healthy individuals may be functionally associated with intracellular mitochondrial signaling pathways and nuclear DNA gene expression. The maintenance of endogenously regulated tissue-specific copy numbers of heteroplasmic mtDNA may represent a sensitive biomarker of homeostasis of mitochondrial dynamics, metabolic integrity, and immune competence. Myeloid cells, monocytes, macrophages, and antigen-presenting dendritic cells undergo programmed changes in mitochondrial metabolism according to innate and adaptive immunological processes. In the central nervous system (CNS), the polarization of activated microglial cells is dependent on strategically programmed changes in mitochondrial function. Therefore, variations in heteroplasmic mtDNA copy numbers may have functional consequences in metabolically competent mitochondria in innate and adaptive immune processes involving the CNS. Recently, altered mitochondrial function has been demonstrated in the progression of coronavirus disease 2019 (COVID-19) due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Accordingly, our review is organized to present convergent lines of empirical evidence that potentially link expression of mtDNA heteroplasmy by functionally interactive CNS cell types to the extent and severity of acute and chronic post-COVID-19 neurological disorders.

scholarly journals Mitochondrial DNA Methylation and Human Diseases

2021 ◽  
Vol 22 (9) ◽  
pp. 4594
Author(s):  
Andrea Stoccoro ◽  
Fabio Coppedè
Keyword(s):  
Dna Methylation ◽  
Mitochondrial Dna ◽  
Mitochondrial Genome ◽  
Nuclear Dna ◽  
Epigenetic Modification ◽  
Nuclear Genome ◽  
Epigenetic Modifications ◽  
Human Diseases ◽  
Loop Region ◽  
D Loop

Epigenetic modifications of the nuclear genome, including DNA methylation, histone modifications and non-coding RNA post-transcriptional regulation, are increasingly being involved in the pathogenesis of several human diseases. Recent evidence suggests that also epigenetic modifications of the mitochondrial genome could contribute to the etiology of human diseases. In particular, altered methylation and hydroxymethylation levels of mitochondrial DNA (mtDNA) have been found in animal models and in human tissues from patients affected by cancer, obesity, diabetes and cardiovascular and neurodegenerative diseases. Moreover, environmental factors, as well as nuclear DNA genetic variants, have been found to impair mtDNA methylation patterns. Some authors failed to find DNA methylation marks in the mitochondrial genome, suggesting that it is unlikely that this epigenetic modification plays any role in the control of the mitochondrial function. On the other hand, several other studies successfully identified the presence of mtDNA methylation, particularly in the mitochondrial displacement loop (D-loop) region, relating it to changes in both mtDNA gene transcription and mitochondrial replication. Overall, investigations performed until now suggest that methylation and hydroxymethylation marks are present in the mtDNA genome, albeit at lower levels compared to those detectable in nuclear DNA, potentially contributing to the mitochondria impairment underlying several human diseases.

Studies of Predators of the Balsam Woolly Aphid, Adelges piceae (Ratz.) (Homoptera: Adelgidae): XI. Cremifania nigrocellulata Cz. (Diptera: Chamaemyiidae), An Introduced Predator in Eastern Canada

1962 ◽  
Vol 94 (11) ◽  
pp. 1171-1175 ◽  
Author(s):  
R. C. Clark ◽  
N. R. Brown
Keyword(s):  
Biological Control ◽  
New Brunswick ◽  
Eastern Canada ◽  
Introduced Predator ◽  
Woolly Aphid ◽  
Commonwealth Institute ◽  
Adelges Piceae ◽  
Research Institute

Cremifania nigrocellulata Cz. is one of the complex of predators that attacks A. piceae (Ratz.) in Europe. After studies on its morphology, biology, and distribution were made by Delucchi and Pschorn-Walcher (1954), C. nigrocellulata was reared in Europe by the Commonwealth Institute of Biological Control and introduced into New Brunswick via the Entomology Research Institute for Biological Control, Belleville, Ontario.

Mitochondrial and nuclear DNA variation, genotype fingerprinting and genetic relationships in lentil (Lens culinaris Medik.)

1997 ◽  
Vol 77 (4) ◽  
pp. 515-521 ◽  
Author(s):  
Om P. Rajora ◽  
John D. Mahon
Keyword(s):  
Mitochondrial Dna ◽  
Restriction Fragment ◽  
Lens Culinaris ◽  
Nuclear Dna ◽  
Genetic Relationships ◽  
Restriction Enzymes ◽  
Dna Variation ◽  
Apocytochrome B ◽  
Nuclear Dna Variation ◽  
Mean Similarity

Mitochondrial DNA (mtDNA) and nuclear DNA (nuDNA) variations were examined in six cultivars of Lens culinaris ssp. culinaris and two (mtDNA) or one (nuDNA) accession(s) of L. culinaris ssp. orientalis. Total leaf DNA was digested with up to 15 restriction endonucleases, separated by agarose gel electrophoresis and trasferred to nylon membranes. To examine mtDNA variation, blots were probed with mtDNA coding for cytochrome c oxidase I (coxI) and ATPase 6 (atp6) of both wheat and maize as well as apocytochrome b (cob) and Orf25 (orf25) of wheat. Sixteen combinations of mtDNA probes and restriction enzymes revealed 34 fragments that discriminated between at least two lentil accessions. For nuDNA analysis, probes from cDNA and genomic DNA clones of lentil were used to probe the same blots, and identified 46 diagnostic fragments from 19 probe/enzyme combinations. Each lentil accession could be unequivocably distinguished from all others on the basis of both mitochondrial and nuclear DNA fragment patterns. The mitochondrial restriction fragment similarities ranged from 0.944 to 0.989, with a mean of 0.970 but nuclear restriction fragment similarities varied from 0.582 to 0.987, with a mean of 0.743. The apparent genetic relationships among accessions differed according to the source of DNA examined, although the commercial varieties Laird, Brewer and Redchief showed similarly high levels of mean similarity with both nuclear (0.982) and mitochondrial DNA (0.983). Key words: Lens culinaris Medik., genetic variation, mitochondrial, nuclear, DNA, lentil

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