scholarly journals Microsatellite markers from Peronospora tabacina, the cause of blue mold of tobacco, reveal species origin, population structure, and high gene flow

2021 ◽  
Author(s):  
Marcin Nowicki ◽  
Denita Hadziabdic Guerry ◽  
Robert N Trigiano ◽  
Fabian Runge ◽  
Marco Thines ◽  
...  
Keyword(s):  
Population Structure ◽  
Genetic Variation ◽  
Gene Flow ◽  
Blue Mold ◽  
Long Distance ◽  
Peronospora Tabacina ◽  
Species Origin ◽  
High Gene Flow ◽  
High Gene ◽  
Wind Currents

Peronospora tabacina is an obligate parasite that causes blue mold of tobacco. The pathogen reproduces primarily asexually by sporangia, and sexual oospores are a rarely observed form of propagation. A collection of 122 isolates of P. tabacina was genotyped using nine microsatellites to assess the population structure of individuals from subpopulations collected from Central, Southern, and Eastern Europe, the Middle East, Central and North America, and Australia. Genetic variation among the six subpopulations accounted for about 8% of total variation with moderate levels of genetic differentiation, high gene flow among these subpopulations, and a positive correlation between geographic and genetic distance (r = 0.225; P<0.001). Evidence of linkage disequilibrium (P<0.001) showed that populations contained partially clonal subpopulations, except subpopulations from Australia and Mediterranean Europe. High genetic variation and population structure among samples could be explained by continuous gene flow across continents via infected transplant exchange and/or long-distance dispersal of sporangia via wind currents. This study analyzed the most numerous P. tabacina collection to date and allowed conclusions on the migration, mutation, and evolutionary history of this obligate biotrophic oomycete. The evidence pointed to the species origin in Australia and identified intra- and inter-continental migration patterns of this important pathogen.

scholarly journals Going with the flow: analysis of population structure reveals high gene flow shaping invasion pattern and inducing range expansion of Mikania micrantha in Asia

2020 ◽  
Vol 125 (7) ◽  
pp. 1113-1126
Author(s):  
Achyut Kumar Banerjee ◽  
Zhuangwei Hou ◽  
Yuting Lin ◽  
Wentao Lan ◽  
Fengxiao Tan ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Genetic Variation ◽  
Gene Flow ◽  
Genetic Distance ◽  
Range Expansion ◽  
Mikania Micrantha ◽  
High Gene Flow ◽  
Genetic Pattern ◽  
High Gene

Abstract Background and Aims Mikania micrantha, a climbing perennial weed of the family Asteraceae, is native to Latin America and is highly invasive in the tropical belt of Asia, Oceania and Australia. This study was framed to investigate the population structure of M. micrantha at a large spatial scale in Asia and to identify how introduction history, evolutionary forces and landscape features influenced the genetic pattern of the species in this region. Methods We assessed the genetic diversity and structure of 1052 individuals from 46 populations for 12 microsatellite loci. The spatial pattern of genetic variation was investigated by estimating the relationship between genetic distance and geographical, climatic and landscape resistances hypothesized to influence gene flow between populations. Key Results We found high genetic diversity of M. micrantha in this region, as compared with the genetic diversity parameters of other invasive species. Spatial and non-spatial clustering algorithms identified the presence of multiple genetic clusters and admixture between populations. Most of the populations showed heterozygote deficiency, primarily due to inbreeding, and the founder populations showed evidence of a genetic bottleneck. Persistent gene flow throughout the invasive range caused low genetic differentiation among populations and provided beneficial genetic variation to the marginal populations in a heterogeneous environment. Environmental suitability was found to buffer the detrimental effects of inbreeding at the leading edge of range expansion. Both linear and non-linear regression models demonstrated a weak relationship between genetic distance and geographical distance, as well as bioclimatic variables and environmental resistance surfaces. Conclusions These findings provide evidence that extensive gene flow and admixture between populations have influenced the current genetic pattern of M. micrantha in this region. High gene flow across the invaded landscape may facilitate adaptation, establishment and long-term persistence of the population, thereby indicating the range expansion ability of the species.

Population structure of the Dover sole, Solea solea L., in a background of high gene flow

1998 ◽  
Vol 40 (1-2) ◽  
pp. 117-129 ◽  
Author(s):  
Athanasios Exadactylos ◽  
Audrey J Geffen ◽  
John P Thorpe
Keyword(s):  
Population Structure ◽  
Gene Flow ◽  
High Gene Flow ◽  
Solea Solea ◽  
High Gene ◽  
Dover Sole

scholarly journals Population genetics of Anopheles arabiensis, the primary malaria vector in the Republic of Sudan

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Mashair Sir El Khatim Mustafa ◽  
Zairi Jaal ◽  
Sumia Abu Kashawa ◽  
Siti Azizah Mohd Nor
Keyword(s):  
Population Genetics ◽  
Population Structure ◽  
Gene Flow ◽  
Malaria Vector ◽  
Microsatellite Loci ◽  
Anopheles Arabiensis ◽  
Isolation By Distance ◽  
Gene Pools ◽  
High Gene Flow ◽  
High Gene

Abstract Background Anopheles arabiensis is a member of Anopheles gambiae complex and the main malaria vector in Sudan. There is insufficient population genetics data available on An. arabiensis for an understanding of vector population structure and genetics, which are important for the malaria vector control programmes in this country. The objective of this investigation is to study the population structure, gene flow and isolation by distance among An. arabiensis populations for developing control strategies. Methods Mosquitoes were collected from six sites located in three different states in Sudan, Khartoum, Kassala and Sennar, using pyrethrum spray catch of indoor resting mosquitoes. Anopheline mosquitoes were identified morphologically and based on species specific nucleotide sequences in the ribosomal DNA intergenic spacers (IGS). Seven published An. gambiae microsatellite loci primers were used to amplify the DNA of An. arabiensis samples. Results PCR confirmed that An. arabiensis was the main malaria vector found in the six localities. Of the seven microsatellite loci utilized, six were found to be highly polymorphic across populations, with high allelic richness and heterozygosity with the remaining one being monomorphic. Deviation from Hardy–Weinberg expectations were found in 21 out of 42 tests in the six populations due to heterozygote deficiency. Bayesian clustering analysis revealed two gene pools, grouping samples into two population clusters; one includes four and the other includes two populations. The clusters were not grouped according to the three states but were instead an admixture. The genetic distances between pairs of populations ranged from 0.06 to 0.24. Significant FST was observed between all pairwise analyses of An. arabiensis populations. The Kassala state population indicated high genetic differentiation (FST ranged from 0.17 to 0.24) from other populations, including one which is also located in the same state. High gene flow (Nm = 1.6–8.2) was detected among populations within respective clusters but limited between clusters particularly with respect to Kassala state. There was evidence of a bottleneck event in one of the populations (Al Haj Yousif site). No isolation by distance pattern was detected among populations. Conclusions This study revealed low levels of population differentiation with high gene flow among the An. arabiensis populations investigated in Sudan, with the exception of Kassala state.

scholarly journals Population Structure and Adaptive Divergence in a High Gene Flow Marine Fish: The Small Yellow Croaker (Larimichthys polyactis)

PLoS ONE ◽  
2016 ◽  
Vol 11 (4) ◽  
pp. e0154020 ◽  
Author(s):  
Bing-Jian Liu ◽  
Bai-Dong Zhang ◽  
Dong-Xiu Xue ◽  
Tian-Xiang Gao ◽  
Jin-Xian Liu
Keyword(s):  
Population Structure ◽  
Gene Flow ◽  
Marine Fish ◽  
Adaptive Divergence ◽  
Larimichthys Polyactis ◽  
Small Yellow Croaker ◽  
High Gene Flow ◽  
High Gene
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