Population Genetic of Anopheles Arabiensis Patton(Diptera: Culicidae) the Malaria Vector in the Republic of Sudan.

2020 ◽  
Author(s):  
Mashair Mustafa ◽  
Zairi Jaal ◽  
Sumia Abu Kashawa ◽  
Siti Azizah Mohd Nor
Keyword(s):  
Population Structure ◽  
Gene Flow ◽  
Malaria Vector ◽  
Microsatellite Loci ◽  
Population Genetic ◽  
Anopheles Arabiensis ◽  
Isolation By Distance ◽  
Gene Pools ◽  
High Gene Flow ◽  
High Gene

Abstract Background Anopheles arabiensis is a member of An. gambiae complex and a main malaria vector in Sudan. There is no sufficient An. arabiensis population genetic data available an understanding of vector population structure and genetics are important to the malaria vector control programs. The objective of this investigation is to study the population structure, gene flow and isolation by distance among An. arabiensis for developing control strategies Methods Mosquitoes were collected from six sites in Sudan using pyrethrum spray catch of indoor resting mosquitoes. Anopheline mosquitos were identified morphologically and based on species specific nucleotide sequences in the ribosomal DNA intergenic spacers (IGS). Seven microsatellite loci published An. gambiae 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 heterozygotes deficiency. Bayesian clustering analysis revealed two gene pools, grouping samples into two population clusters; one includes four and the other includes two populations. The genetic distances between pairs of populations ranged from 0.06 to 0.24. Significant F ST was observed between all An. arabiensis populations . Kr population indicated high genetic differentiation (F ST ranged from 0.17 to 0.24). High gene flow (Nm= 1.6–8.2) was detected between clusters. There was evidence of a bottleneck event in the Hj population. No isolation by distance pattern was detected among populations. Conclusions This study revealed low levels of population differentiation with high gene flow among six An. arabiensis populations in Sudan.

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 Host movement and the genetic structure of populations of parasitic nematodes.

Genetics ◽  
1995 ◽  
Vol 141 (3) ◽  
pp. 1007-1014 ◽  
Author(s):  
M S Blouin ◽  
C A Yowell ◽  
C H Courtney ◽  
J B Dame
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
Population Genetic ◽  
Isolation By Distance ◽  
Parasitic Nematodes ◽  
Great Opportunity ◽  
High Gene Flow ◽  
Mtdna Sequence ◽  
High Gene ◽  
Host Movement

Abstract Mitochondrial DNA (mtDNA) sequence data were used to compare the population genetic structures of five species of parasitic nematodes from three different hosts: Ostertagia ostertagi and Haemonchus placei from cattle, H. contortus and Teladorsagia circumcincta from sheep, and Mazamastrongylus odocoilei from white-tailed deer. The parasites of sheep and cattle showed a pattern consistent with high gene flow among populations. The parasite of deer showed a pattern of substantial population subdivision and isolation by distance. It appears that host movement is an important determinant of population genetic structure in these nematodes. High gene flow in the parasites of livestock also indicates great opportunity for the spread of rare alleles that confer resistance to anthelmintic drugs. All species, including the parasite of deer, had unusually high within-population diversities (averages of 0.019-0.027 substitutions per site between pairs of individuals from the same population). Large effective population sizes (Ne), perhaps in combination with rapid mtDNA evolution, appear to be the most likely explanation for these high within-population diversities.

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 structure and dispersal across small and large spatial scales in a direct developing marine isopod

2020 ◽  
Author(s):  
William S. Pearman ◽  
Sarah J. Wells ◽  
Olin K. Silander ◽  
Nikki E. Freed ◽  
James Dale
Keyword(s):  
Population Structure ◽  
Gene Flow ◽  
Population Genetic ◽  
Isolation By Distance ◽  
Spatial Scales ◽  
Population Connectivity ◽  
Clear Pattern ◽  
Small Spatial Scale ◽  
Cook Strait ◽  
Genetic Break

AbstractMarine organisms generally exhibit one of two developmental modes: biphasic, with distinct adult and larval morphology, and direct development, in which larvae resemble adults. Developmental mode is thought to significantly influence dispersal, with direct developers expected to have much lower dispersal potential. However, in contrast to our relatively good understanding of dispersal and population connectivity for biphasic species, comparatively little is known about direct developers. In this study, we use a panel of 8,020 SNPs to investigate population structure and gene flow for a direct developing species, the New Zealand endemic marine isopod Isocladus armatus. On a small spatial scale (20 kms), gene flow between locations is extremely high and suggests an island model of migration. However, over larger spatial scales (600km), populations exhibit a clear pattern of isolation-by-distance. Because our sampling range is intersected by two well-known biogeographic barriers (the East Cape and the Cook Strait), our study provides an opportunity to understand how such barriers influence dispersal in direct developers. Our results indicate that I. armatus exhibits significant migration across these barriers, and suggests that ocean currents associated with these locations do not present a barrier to dispersal. Interestingly, we do find evidence of a north-south population genetic break occurring between Māhia and Wellington, two locations where there are no obvious biogeographic barriers between them. We conclude that developmental life history largely predicts dispersal in intertidal marine isopods. However, localised biogeographic processes can disrupt this expectation.

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.

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