scholarly journals Comparative population genetic structure of two Ixodidae ticks (Ixodes ovatus and Haemaphysalis flava) in Niigata Prefecture, Japan

2019 ◽  
Author(s):  
Maria Angenica Fulo Regilme ◽  
Megumi Sato ◽  
Tsutomu Tamura ◽  
Reiko Arai ◽  
Marcello Otake Sato ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Large Scale ◽  
Southern China ◽  
Isolation By Distance ◽  
Mantel Test ◽  
Rrna Gene ◽  
Data Set ◽  
Genetic Groups ◽  
Niigata Prefecture ◽  
Haemaphysalis Flava

AbstractIxodid tick species such as Ixodes ovatus and Haemaphysalis flava are important vector of tick-borne diseases in Japan. In this study, we used genetic structure at two mitochondrial loci (cox1, 16S rRNA gene) to infer gene flow patterns of I. ovatus and H. flava from Niigata Prefecture, Japan. Samples were collected in 29 (I. ovatus) and 17 (H. flava) sampling locations across Niigata Prefecture (12,584.18 km2). For I. ovatus, pairwise FST and analysis of molecular variance (AMOVA) analyses of cox1 sequences indicated significant among-population differentiation. This was in contrast to H. flava, for which there were few cases of low significant pairwise differentiation. A Mantel test revealed isolation by distance and there was positive spatial autocorrelation of haplotypes in I. ovatus cox1 and 16S sequences, but non-significant results were observed in H. flava in both markers. We found three genetic groups (China 1, China 2 and Japan) in the cox1 I. ovatus tree. Newly sampled I. ovatus grouped together with a published I. ovatus sequence from northern Japan and were distinct from two other I. ovatus groups that were reported from southern China. The three genetic groups in our data set suggest the potential for cryptic species among the groups. While many factors can potentially account for the observed differences in genetic structure between the two species, including population persistence and large-scale patterns of range expansion, the differences in the mobility of hosts of tick immature stages (small mammals in I. ovatus; birds in H. flava) is possibly driving the observed patterns.

Comparative population genetic structure of two Ixodidae ticks (Ixodes ovatus and Haemaphysalis flava) in Niigata Prefecture, Japan 

2019 ◽  
Author(s):  
Maria Angenica Fulo Regilme ◽  
Megumi Sato ◽  
Tsutomu Tamura ◽  
Reiko Arai ◽  
Marcello Otake Sato ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
Southern China ◽  
Isolation By Distance ◽  
Rrna Gene ◽  
Data Set ◽  
Genetic Groups ◽  
Niigata Prefecture ◽  
Haemaphysalis Flava

Abstract Background Ixodid tick species such as Ixodes ovatus and Haemaphysalis flava function as important vectors of tick-borne diseases in Japan. The study of the genetic patterns of tick populations can reveal information regarding the spread of tick-borne disease. We hypothesized that I. ovatus and H. flava have different population genetic structure because of their host mobility in different tick life stages despite sharing of hosts. Methods Samples (n = 1 to 77) were collected in 29 (I. ovatus) and 17 (H. flava) sampling locations across Niigata. In this study, we used genetic structure at two mitochondrial loci (cox1, 16S rRNA gene) to infer gene flow patterns of I. ovatus and H. flava from Niigata Prefecture, Japan. Results For I. ovatus, pairwise FST and analysis of molecular variance (AMOVA) analyses of cox1 sequences indicated significant among-population differentiation. This was in contrast to H. flava, for which there were only two cases of significant pairwise differentiation and no overall structure. A Mantel test revealed isolation by distance and there was positive spatial autocorrelation of haplotypes in I. ovatus cox1 and 16S sequences, but non-significant results were observed in H. flava in both markers. We found three genetic groups (China 1, China 2 and Japan) in the cox1 I. ovatus tree. Newly sampled I. ovatus grouped together with a published I. ovatus sequence from northern Japan and were distinct from two other I. ovatus groups that were reported from southern China. Conclusions The three genetic groups in our data set suggest the potential for cryptic species within the lineage. While many factors can potentially account for the observed differences in genetic structure, including population persistence and large-scale patterns of range expansion, we propose that differences in the mobility of hosts of tick immature stages (small mammals in I. ovatus; birds in H. flava) may be driving the observed patterns.

scholarly journals Population genetic structure and putative migration pathway of Sogatella furcifera (Horváth) (Hemiptera, Delphacidae) in Asia

2018 ◽  
Vol 109 (4) ◽  
pp. 453-462 ◽  
Author(s):  
H. Y. Nam ◽  
K. S. Kim ◽  
J.-H. Lee
Keyword(s):  
Genetic Structure ◽  
Southern China ◽  
Isolation By Distance ◽  
Resistance Management ◽  
Mantel Test ◽  
Assignment Test ◽  
Migration Route ◽  
Sogatella Furcifera ◽  
Distance Analysis ◽  
Migration Pathway

AbstractThe white-backed planthopper, Sogatella furcifera (Horváth) (Hemiptera, Delphacidae), has emerged as a serious rice pest in Asia. In the present study, 12 microsatellite markers were employed to investigate the genetic structure, diversity and migration route of 43 populations sampled from seven Asian countries (Bangladesh, China, Korea, Laos, Nepal, Thailand, and Vietnam). According to the isolation by distance analysis, a significant positive correlation was observed between genetic and geographic distances by the Mantel test (r2 = 0.4585, P = 0.01), indicating the role of geographic isolation in the genetic structure of S. furcifera. A population assignment test using the first-generation migrants detection method (thresholds a = 0.01) revealed southern China and northern Vietnam as the main sources of S. furcifera in Korea. Nepal and Bangladesh might be additional potential sources via interconnection with Vietnam populations. This paper provides useful data for the migration route and origin of S. furcifera in Korea and will contribute to planthopper resistance management.

scholarly journals Genetic structure and dispersal patterns of the invasive psocid Liposcelis decolor (Pearman) in Australian grain storage systems

2010 ◽  
Vol 100 (5) ◽  
pp. 521-527 ◽  
Author(s):  
K.M. Mikac ◽  
N.N. FitzSimmons
Keyword(s):  
Genetic Structure ◽  
Isolation By Distance ◽  
Geographic Distance ◽  
Allelic Diversity ◽  
Mantel Test ◽  
Null Alleles ◽  
Dispersal Patterns ◽  
Long Distance ◽  
Population Comparisons ◽  
Low Levels

AbstractMicrosatellite markers were used to investigate the genetic structure among invasive L. decolor populations from Australia and a single international population from Kansas, USA to determine patterns of dispersal. Six variable microsatellites displayed an average of 2.5–4.2 alleles per locus per population. Observed (HO) heterozygosity ranged from 0.12–0.65 per locus within populations; but, in 13 of 36 tests, HO was less than expected. Despite low levels of allelic diversity, genetic structure estimated as θ was significant for all pairwise comparisons between populations (θ=0.05–0.23). Due to suspected null alleles at four loci, ENA (excluding null alleles) corrected FST estimates were calculated overall and for pairwise population comparisons. The ENA-corrected FST values (0.02–0.10) revealed significant overall genetic structure, but none of the pairwise values were significantly different from zero. A Mantel test of isolation by distance indicated no relationship between genetic structure and geographic distance among all populations (r2=0.12, P=0.18) and for Australian populations only (r2=0.19, P=0.44), suggesting that IBD does not describe the pattern of gene flow among populations. This study supports a hypothesis of long distance dispersal by L. decolor at moderate to potentially high levels.

Delineating genetic groupings in continuously distributed species across largely homogeneous landscapes: a study of American black bears (Ursus americanus) in Ontario, Canada

2012 ◽  
Vol 90 (8) ◽  
pp. 999-1014 ◽  
Author(s):  
A. Pelletier ◽  
M.E. Obbard ◽  
K. Mills ◽  
E.J. Howe ◽  
F.G. Burrows ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Large Scale ◽  
Ursus Americanus ◽  
Isolation By Distance ◽  
Black Bears ◽  
Clinal Variation ◽  
Isolated Populations ◽  
Anthropogenic Pressures ◽  
American Black ◽  
American Black Bears

There is a crucial need to understand the genetic consequences of landscape modifications on continuous populations that could become fragmented, and to evaluate the degree of differentiation of isolated populations that were historically part of the core. Using 15 microsatellite loci, we evaluated the genetic structure of American black bears ( Ursus americanus Pallas, 1780) across a vast, contiguous Ontario landscape (>1 × 106 km2) that largely represents their pre-European settlement distribution. Because geographic barriers are absent, we predicted that isolation by distance would drive genetic structure. We identified three genetic clusters (Northwest, Southeast, and Bruce Peninsula) that were less differentiated than when assessed with mtDNA, suggesting the influence of male-biased dispersal on large-scale genetic differentiation. Isolation by distance (r = 0.552, P = 0.001) was supported by a weak, clinal variation between Northwest and Southeast, illustrating the challenges to delineate populations in wide-ranging taxa. The Bruce Peninsula cluster, confined to a small area under strong anthropogenic pressures, was more differentiated from neighbouring clusters (FST > 0.13, P < 0.0001), with a genetic diversity corresponding to disjunct populations of black bears. Our results could be used in landscape genetics models to project the evolution of population differentiation based on upcoming landscape modifications in northern regions of North America.

Microsatellite analyses of spatial genetic structure in darkblotched rockfish (Sebastes crameri): Is pooling samples safe?

2005 ◽  
Vol 62 (8) ◽  
pp. 1874-1886 ◽  
Author(s):  
Daniel Gomez-Uchida ◽  
Michael A Banks
Keyword(s):  
Genetic Structure ◽  
Isolation By Distance ◽  
Spatial Genetic Structure ◽  
Geographic Distance ◽  
Original Data ◽  
Dispersal Distance ◽  
Data Set ◽  
Limited Dispersal ◽  
Composite Samples ◽  
Microsatellite Analyses

By pooling or removing samples of small size, we investigated how results from microsatellite analyses of spatial genetic structure in darkblotched rockfish (Sebastes crameri) were affected. Genotypes from six and seven microsatellite loci from 1206 specimens collected offshore from Washington to California were employed in the analyses. Sample sizes varied greatly among locations (n = 11–114). When adjacent samples of n < 25 were pooled using an absolute genetic distance (FST ≤ 0), the correlation between genetic and geographic distance found in the original data set increased nearly twofold, and overall FST (95% confidence interval) increased from 0.001 (0.000–0.002) to 0.002 (0.001–0.003). Removing samples where n < 25 gave a similar result, yet the correlation increase was smaller. Another pooling strategy based on similarity tests allowed larger sizes in composite samples (n > 100) and further increased the correlation, although this strategy did not raise overall FST. These results indicate that under genetic isolation by distance, excessive pooling might not enhance the overall genetic differentiation among populations. The regression slope in isolation by distance plots was robust throughout all treatments, and its value suggests limited dispersal distance on this species.

scholarly journals The interacting effects of genetic variation in Geranium subg. Geranium (Geraniaceae) using scot molecular markers

Caryologia ◽  
2021 ◽  
Vol 74 (3) ◽  
pp. 141-150
Author(s):  
Bo Shi ◽  
Majid Khayatnezhad ◽  
Abdul Shakoor
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Biological Diversity ◽  
Isolation By Distance ◽  
Morphological Characters ◽  
Mantel Test ◽  
Conservation Strategies ◽  
High Genetic Diversity ◽  
Information Index ◽  
Narrow Endemic

One of the most crucial aspects of biological diversity for conservation strategies is genetic diversity, particularly in rare and narrow endemic species. Our study is the first attempt to utilize SCoT markers to check the genetic diversity in Iran. We used 115 plant samples. Our objectives were 1) to check genetic diversity among Geranium species 2) Genetic structure of the Geranium 3) Do the Geranium species exchange genes? 4) To detect isolation by distance among the Geranium species. We used traditional morphological and molecular methods to assess genetic diversity and genetic structure in the Geranium species. A total of 129 amplified polymorphic bands were generated across 13 Geranium species. The size of the amplified fragments ranged from 150 to 3000 bp. G. stepporum showed the highest values for the effective number of alleles (Ne = 1.30) and Shannon information index (I =0.35). Significant ANOVA results (P <0.01) showed differences in quantitative morphological characters in plant species. G. sylvaticum showed high genetic diversity. Mantel test showed a significant correlation (r = 0.17, p=0.0002) between genetic distance and geographical distance, so isolation by distance (IBD) occurred among the Geranium species. According to the SCoT markers analysis, G. kotschyi and G. dissectum had the lowest similarity, and the species of G. sylvaticum and G. pratense had the highest similarity. The present study revealed that a combination of morphological and SCoT methods could distinguish the species of Geranium.

Population genetic structure and secondary endosymbionts of Q Bemisia tabaci (Hemiptera: Aleyrodidae) from Greece

2012 ◽  
Vol 102 (3) ◽  
pp. 353-365 ◽  
Author(s):  
A. Tsagkarakou ◽  
L. Mouton ◽  
J.B. Kristoffersen ◽  
E. Dokianakis ◽  
M. Grispou ◽  
...  
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
Bemisia Tabaci ◽  
Molecular Diversity ◽  
Isolation By Distance ◽  
Geographic Distance ◽  
Cultivated Plants ◽  
High Frequencies ◽  
Genetic Groups ◽  
Aegean Islands

AbstractWe investigated the molecular diversity of the major agricultural pest Bemisia tabaci and of its associated secondary endosymbionts in Greece. Analyzing mitochondrial DNA, we found that the Q1 (=Q west) is predominant. We used eight microsatellite polymorphic markers to study the genetic structure of 37 populations from mainland and insular Greece, collected on different host species from outdoor and protected crops as well as from non-cultivated plants. In some cases, gene flow was found to be low even between populations separated by just a few kilometres. Bayesian analysis identified two main genetic groups, the first encompassing populations from south Crete and the second composed of populations from north Crete, two other Aegean islands and mainland Greece. Genetic differentiation was not correlated with different host plant species or habitat, or greenhouse versus open environment populations. Gene flow significantly decreased with geographic distance, but no isolation by distance existed when only the samples from mainland Greece or only the samples from Crete were considered. The secondary symbionts Wolbachia and Hamiltonella were present at high frequencies while Arsenophonus, Cardinium and Rickettsia were absent from Greek populations. Multilocus sequence typing of Wolbachia identified two Wolbachia strains. These two strains were found together in most of the populations studied but never in the same host individual. Their role on the observed population structure is discussed.

scholarly journals Effects of Colonization, Geography and Environment on Genetic Divergence in the Intermediate Leaf-Nosed Bat, Hipposideros larvatus

Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 733
Author(s):  
Xiangfeng Meng ◽  
Tong Liu ◽  
Lin Zhang ◽  
Longru Jin ◽  
Keping Sun ◽  
...  
Keyword(s):  
Population Structure ◽  
Genetic Variation ◽  
Evolutionary Biology ◽  
Large Scale ◽  
Southern China ◽  
Isolation By Distance ◽  
Mainland China ◽  
Hainan Island ◽  
Colonization History ◽  
Evolutionary Forces

Determining the evolutionary history and population drivers, such as past large-scale climatic oscillations, stochastic processes and ecological adaptations, represents one of the aims of evolutionary biology. Hipposideros larvatus is a common bat species in Southern China, including Hainan Island. We examined genetic variation in H. larvatus using mitochondrial DNA and nuclear microsatellites. We found a population structure on both markers with a geographic pattern that corresponds well with the structure on mainland China and Hainan Island. To understand the contributions of geography, the environment and colonization history to the observed population structure, we tested isolation by distance (IBD), isolation by adaptation (IBA) and isolation by colonization (IBC) using serial Mantel tests and RDA analysis. The results showed significant impacts of IBD, IBA and IBC on neutral genetic variation, suggesting that genetic variation in H. larvatus is greatly affected by neutral processes, environmental adaptation and colonization history. This study enriches our understanding of the complex evolutionary forces that shape the distribution of genetic variation in bats.

scholarly journals Population Genetic Structure of Clinical and Environmental Isolates of Blastomyces dermatitidis, Based on 27 Polymorphic Microsatellite Markers

2011 ◽  
Vol 77 (15) ◽  
pp. 5123-5131 ◽  
Author(s):  
Jennifer K. Meece ◽  
Jennifer L. Anderson ◽  
Matthew C. Fisher ◽  
Daniel A. Henk ◽  
Brian L. Sloss ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Microsatellite Markers ◽  
Mating Type ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
Blastomyces Dermatitidis ◽  
Environmental Isolates ◽  
Data Set ◽  
Content Type ◽  
Genetic Groups

ABSTRACTBlastomyces dermatitidis, a thermally dimorphic fungus, is the etiologic agent of North American blastomycosis. Clinical presentation is varied, ranging from silent infections to fulminant respiratory disease and dissemination to skin and other sites. Exploration of the population genetic structure ofB. dermatitidiswould improve our knowledge regarding variation in virulence phenotypes, geographic distribution, and difference in host specificity. The objective of this study was to develop and test a panel of microsatellite markers to delineate the population genetic structure within a group of clinical and environmental isolates ofB. dermatitidis. We developed 27 microsatellite markers and genotypedB. dermatitidisisolates from various hosts and environmental sources (n=112). Assembly of a neighbor-joining tree of allele-sharing distance revealed two genetically distinct groups, separated by a deep node. Bayesian admixture analysis showed that two populations were statistically supported. Principal coordinate analysis also reinforced support for two genetic groups, with the primary axis explaining 61.41% of the genetic variability. Group 1 isolates average 1.8 alleles/locus, whereas group 2 isolates are highly polymorphic, averaging 8.2 alleles/locus. In this data set, alleles at three loci are unshared between the two groups and appear diagnostic. The mating type of individual isolates was determined by PCR. Both mating type-specific genes, the HMG and α-box domains, were represented in each of the genetic groups, with slightly more isolates having the HMG allele. One interpretation of this study is that the species currently designatedB. dermatitidisincludes a cryptic subspecies or perhaps a separate species.

scholarly journals Morphological method and molecular marker determine genetic diversity and population structure in Allochrusa

Caryologia ◽  
2021 ◽  
Vol 74 (2) ◽  
pp. 121-130
Author(s):  
Kun Zhu ◽  
Lijie Liu ◽  
Shanshan Li ◽  
Bo Li ◽  
Majid Khayatnezhad ◽  
...  
Keyword(s):  
Isolation By Distance ◽  
Group Analysis ◽  
Issr Markers ◽  
Mantel Test ◽  
Plant Systematics ◽  
The Past ◽  
Genetic Groups ◽  
Morphometry Analysis ◽  
Floral Characters ◽  
Test Result

The Caryophyllaceae family is complex. Several attempts have been carried out in the past to study Caryophyllaceae members. This study mainly focused on Allochrusa Bunge to determine its genetic structure and used ISSR markers, ITS, and rps16 data to classify and differentiate Allochrusa species. We collected 122 Allochrusa specimens. Our analysis included morphological and molecular method approaches. Morphometry analysis indicated that floral characters could assist in the identification of Allochrusa species. A. persica (Boiss.) Boiss. and A. versicolor Fisch. & C.A.Mey. showed affinity to each other. A. bungei Boiss. formed a separate group. Analysis of molecular variance showed significant genetic differentiation in Allochrusa (p= 0.001). The majority of genetic variation was among the Allochrusa population. We recorded minimum gene flow (Nm=0.176) between Allochrusa species. Besides this, isolation by distance occurs in Allochrusa members, as shown in the Mantel test result (r = 0.01, p = 0.0002). STRUCTURE analysis revealed three genetic groups. It is evident that A. persica, A. versicolor, and A. bungei differ genetically from each other. Our current findings have implications in plant systematics and biodiversity management.

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