Patterns of genetic divergence among populations of Aedes aegypti L. (Diptera: Culicidae) in the southeastern USA

Abstract Background The yellow fever mosquito, Aedes aegypti is a public health concern in the USA, especially in the wake of emergent diseases such as Zika and chikungunya. Aedes aegypti populations dwindled after the invasion of Aedes albopictus in the 1980s and many populations were extirpated. However, in some areas Ae. aegypti persisted in small populations and there are reports of recent resurgences of Ae. aegypti in Florida, Louisiana, Nevada and California. We assessed the population genetic structure of Ae. aegypti in Florida and Georgia, which has concomitant consequences related to mosquito dispersal, pesticide resistance and vectorial capacity. Methods We collected Ae. aegypti across Florida and in Georgia using ovitraps. We hatched the eggs and reared them to adults, and after sacrifice we extracted their DNA. We then probed each individual for variation in 6 microsatellite markers, which we used to address population genetic characteristics. Results We collected Ae. aegypti and genotyped seven Florida populations and one Georgia population using microsatellite markers. We found evidence of isolation by distance model of gene flow supported by driving distance among cities within Florida and two theoretic genetic clusters. Conclusions Significant genetic structure between some populations with substantial gene flow between geographically distant cities suggests regional genetic structuring of Ae. aegypti in Florida. This study provides information on the genetic exchange between populations of Ae. aegypti in the southeastern USA and suggests potential routes of spread of this species.

Download Full-text

The influence of roads on the fine-scale population genetic structure of the dengue vector Aedes aegypti (Linnaeus)

PLoS Neglected Tropical Diseases ◽

10.1371/journal.pntd.0009139 ◽

2021 ◽

Vol 15 (2) ◽

pp. e0009139

Author(s):

Maria Angenica F. Regilme ◽

Thaddeus M. Carvajal ◽

Ann–Christin Honnen ◽

Divina M. Amalin ◽

Kozo Watanabe

Keyword(s):

Gene Flow ◽

Genetic Structure ◽

Aedes Aegypti ◽

Spatial Scale ◽

Population Genetic Structure ◽

Population Genetic ◽

Mosquito Control ◽

Genetic Admixture ◽

Fine Spatial Scale ◽

The Road

Dengue is endemic in tropical and subtropical countries and is transmitted mainly by Aedes aegypti. Mosquito movement can be affected by human-made structures such as roads that can act as a barrier. Roads can influence the population genetic structure of Ae. aegypti. We investigated the genetic structure and gene flow of Ae. aegypti as influenced by a primary road, España Boulevard (EB) with 2000-meter-long stretch and 24-meters-wide in a very fine spatial scale. We hypothesized that Ae. aegypti populations separated by EB will be different due to the limited gene flow as caused by the barrier effect of the road. A total of 359 adults and 17 larvae Ae. aegypti were collected from June to September 2017 in 13 sites across EB. North (N1-N8) and South (S1-S5) comprised of 211 and 165 individuals, respectively. All mosquitoes were genotyped at 11 microsatellite loci. AMOVA FST indicated significant genetic differentiation across the road. The constructed UPGMA dendrogram found 3 genetic groups revealing the clear separation between North and South sites across the road. On the other hand, Bayesian cluster analysis showed four genetic clusters (K = 4) wherein each individual samples have no distinct genetic cluster thus genetic admixture. Our results suggest that human-made landscape features such as primary roads are potential barriers to mosquito movement thereby limiting its gene flow across the road. This information is valuable in designing an effective mosquito control program in a very fine spatial scale.

Download Full-text

Absence of Population Genetic Structure Among Breeding Colonies of the Waved Albatross

The Condor ◽

10.1093/condor/108.2.440 ◽

2006 ◽

Vol 108 (2) ◽

pp. 440-445 ◽

Cited By ~ 1

Author(s):

Kathryn P. Huyvaert ◽

Patricia G. Parker

Keyword(s):

Genetic Variation ◽

Gene Flow ◽

Genetic Structure ◽

Population Genetic Structure ◽

Population Genetic ◽

Breeding Population ◽

Genetic Structuring ◽

Galapagos Archipelago ◽

Phoebastria Irrorata ◽

Waved Albatrosses

Abstract We used four variable microsatellite loci to examine the distribution of genetic variation and degree of genetic structuring among three subcolonies of Waved Albatrosses (Phoebastria irrorata). The breeding population of this species is almost entirely limited to the island of Española in the Galápagos Archipelago. Such strong philopatry could lead to population genetic structure among subcolonies on the island. Pairwise values of the FST analog, θ, calculated from microsatellite genotypes, were all less than 0.012, indicating little genetic differentiation and the presence of gene flow throughout the population.

Download Full-text

Population Genetic Structure of the German Cockroach (Blattodea: Blattellidae) in Apartment Buildings

Journal of Medical Entomology ◽

10.1093/jmedent/47.4.553 ◽

2010 ◽

Vol 47 (4) ◽

pp. 553-564 ◽

Cited By ~ 23

Author(s):

Jonathan R. Crissman ◽

Warren Booth ◽

Richard G. Santangelo ◽

Dmitry V. Mukha ◽

Edward L. Vargo ◽

...

Keyword(s):

Gene Flow ◽

Genetic Structure ◽

Population Genetic Structure ◽

Population Genetic ◽

Population Control ◽

Isolation By Distance ◽

German Cockroach ◽

Common Source ◽

Apartment Complex ◽

Apartment Complexes

Abstract The German cockroach, Blattella germanica (L.) (Blattodea: Blattellidae), is a major residential pest with the potential to vector various pathogens and produce and disseminate household allergens. Understanding population genetic structure and differentiation of this important pest is critical to efforts to eradicate infestations, yet little is known in this regard. Using highly polymorphic microsatellite markers, we investigated patterns of genetic diversity and differentiation within and among 18 apartments from six apartment complexes located in Raleigh, NC. No departure from panmixia was found between rooms within apartments, indicating that active dispersal resulting in gene flow may occur among rooms within apartment units. Alternatively, aggregations within apartments may exist in relative isolation under a metapopulation framework, derived from a recent, common source. Thus, in the event of population control practices leading to incomplete cockroach eradication within an apartment, recolonization of shelters and rooms is likely to occur from a genetically similar aggregation. A pattern of isolation-by-distance across the six apartment complexes indicated that dispersal was more common within complexes than among them, and F statistics suggested greater genetic similarity between apartments in a single building than between separate buildings of an apartment complex. Similarly, neighbor-joining tree and Bayesian clustering analyses were able to cluster only those apartments that were within a single building, indicating higher dispersal with associated gene flow within buildings than between them. The lack of any broader connectivity, as indicated by significant FST and G-tests suggests that human-mediated dispersal of B. germanica between buildings of an apartment complex or between complexes occurs infrequently enough to have negligible effects on gene flow.

Download Full-text

The influence of roads on the fine-scale population genetic structure of the dengue vector Aedes aegypti (Linnaeus)

10.1101/2020.09.07.285528 ◽

2020 ◽

Author(s):

Maria Angenica Fulo Regilme ◽

Thaddeus Carvajal ◽

Ann –Christin Honnen ◽

Divina Amalin ◽

Kozo Watanabe

Keyword(s):

Gene Flow ◽

Genetic Structure ◽

Aedes Aegypti ◽

Spatial Scale ◽

Population Genetic Structure ◽

Population Genetic ◽

Population Control ◽

Control Program ◽

Fine Spatial Scale ◽

The Road

AbstractDengue is endemic in tropical and subtropical countries and is transmitted mainly by Aedes aegypti. Mosquito movement can be affected by human-made structures such as roads that can act as a barrier. Roads can influence the population genetic structure of Ae. aegypti. We investigated the genetic structure and gene flow of Ae. aegypti as influenced by a primary road, España Boulevard (EB) with 2000-meter-long stretch and 24-meters-wide in a very fine spatial scale. We hypothesized that Ae. aegypti populations separated by EB will be different due to the limited gene flow as caused by the barrier effect of the road. A total of 376 adults and larval Ae. aegypti were collected from June to September 2017 in 21 sites across EB. North (N1-N11) and South (S1-S10) comprised of 211 and 165 individuals, respectively. All mosquitoes were genotyped at 11 microsatellite loci. AMOVA FST indicated significant genetic differentiation across the road. The constructed UPGMA dendrogram found 4 genetic groups revealing the clear separation between North and South sites across the road. On the other hand, Bayesian cluster analysis showed four genetic clusters (K = 4) wherein each individual samples have no distinct genetic cluster thus genetic admixture. Moreover, significant positive spatial autocorrelation was observed at 100 - 200 m distance class, suggesting dispersal potential of the adult mosquitoes within a 200 m spatial scale. Our results suggest that human-made landscape features such as primary roads are potential barriers to mosquito movement thereby limiting its gene flow across the road. This information is valuable in designing an effective mosquito control program in a very fine spatial scale.Author SummaryDengue, a mosquito-borne viral infection is a serious health problem in tropical and subtropical countries such as Philippines. Most dengue prevention programs aim to eradicate its mosquito vector, Aedes aegypti. A successful population control program is reliant in understanding the mosquito behavior and ecology including how human-made structures such as roads influence its expansion and movement. Previous studies have discovered the barrier effect of roads in the movement of mosquitoes. In this study, we examined the influence of roads in the population genetic structure of Ae. aegypti in a fine spatial scale using 11 microsatellite markers. We found significant genetic differentiation of mosquito populations across the road. Our results suggest limited gene flow across the road and supports our hypothesis that roads are potential barriers to mosquito dispersal. This information can be used in designing an effective mosquito population control zones in perceived barrier to mosquito dispersal such as roads.

Download Full-text

Microsatellite loci and the complete mitochondrial DNA sequence characterised through next-generation sequencing and de novo genome assembly, and a preliminary assessment of population genetic structure for the Australian crane, Antigone rubicunda

Avian Biology Research ◽

10.1177/1758155919832142 ◽

2019 ◽

Vol 12 (2) ◽

pp. 49-58

Author(s):

Adam D Miller ◽

Inka Veltheim ◽

Timothy Nevard ◽

Han Ming Gan ◽

Martin Haase

Keyword(s):

Gene Flow ◽

Next Generation Sequencing ◽

Genetic Structure ◽

Mitochondrial Genome ◽

Microsatellite Markers ◽

Genome Sequence ◽

Population Genetic ◽

De Novo ◽

South Eastern ◽

Generation Sequencing

The Brolga ( Antigone rubicunda) is a large Australian crane species with a broad distribution spanning from the tropical north to the south-eastern regions of the continent. Brolga populations throughout New South Wales, Victoria and South Australia have been in decline since the early twentieth century, with the species being listed as vulnerable in each state. To aid future conservation of the species, its taxonomic status needs to be validated, and patterns of gene flow and population connectivity across the species distribution need to be understood. To assist future genetic studies, we developed a suite of polymorphic microsatellite markers and the complete mitochondrial genome sequence by next-generation sequencing. A total of 18 polymorphic loci were characterised using DNA extractions from 47 individuals, comprising 30 and 17 individuals from Victoria and northern Australia, respectively. We observed moderate genetic variation across loci with only a single locus deviating significantly from Hardy–Weinberg equilibrium. De novo and reference-based genome assemblies were used to assemble the A. rubicunda mitochondrial genome sequence, which consists of 16,700 base pairs, and a typical metazoan mitochondrial gene content and arrangement. We test these new markers by conducting a preliminary analysis of genetic structure between south-eastern and northern Australian Brolga populations. Mitochondrial analyses provided evidence of shared haplotypes across the species range supporting the conspecific status of extant populations, while microsatellite markers indicated weak but significant genetic differentiation suggesting gene flow is limited. We discuss the implications of these findings and the benefits that these genetic markers will provide for future population genetic research on this iconic Australian bird species.

Download Full-text

Genetic structure of Lycorma delicatula (Hemiptera: Fulgoridae) populations in Korea: implication for invasion processes in heterogeneous landscapes

Bulletin of Entomological Research ◽

10.1017/s0007485313000011 ◽

2013 ◽

Vol 103 (4) ◽

pp. 414-424 ◽

Cited By ~ 17

Author(s):

Marana Park ◽

Kyung-Seok Kim ◽

Joon-Ho Lee

Keyword(s):

Gene Flow ◽

Genetic Structure ◽

South Korea ◽

Isolation By Distance ◽

Assignment Test ◽

Invasive Pest ◽

Genetic Structuring ◽

Long Distance ◽

Heterogeneous Landscapes ◽

Lycorma Delicatula

AbstractLycorma delicatula (White) was identified in 2004 as an invasive pest in South Korea, where it causes serious damage to vineyard crops. To investigate the population structure and dispersal pattern of L. delicatula in South Korea, we estimated the population genetic structure and gene flow among nine locations across the country using seven microsatellite markers. Although L. delicatula spread throughout most of its geographical range in South Korea within 5–7 years following invasion, its populations show evidence of genetic structuring across the range with a low but significant global FST (genetic differentiation across all populations) of 0.0474. Bayesian-based clustering analysis indicates the presence of at least three genetically unique populations in South Korea, including populations in northeastern South Korea, which show a distinct genetic background. However, isolation by distance suggests that populations in South Korea have not yet reached genetic equilibrium. Estimates of the historical rate of gene flow (Nem) indicate that relatively high rates of flow have been maintained among populations within the western region, which may indicate recent range expansion. A population assignment test using the first-generation migrant detection method suggested that long-distance dispersal of L. delicatula may have occurred over large areas of South Korea. More complex dispersal patterns may have occurred during L. delicatula invasion of heterogeneous landscapes in South Korea.

Download Full-text

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

Genetics ◽

10.1093/genetics/141.3.1007 ◽

1995 ◽

Vol 141 (3) ◽

pp. 1007-1014 ◽

Cited By ~ 10

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.

Download Full-text

Population genetic structure and phenotypic diversity of Aspidodera raillieti (Nematoda: Heterakoidea), a parasite of Didelphini marsupials in Brazil’s South and Southeast Atlantic Forest

10.21203/rs.3.rs-1192398/v1 ◽

2021 ◽

Author(s):

Karina Varella ◽

Roberto do Val Vilela ◽

Rosana Gentile ◽

Thiago dos Santos Cardoso ◽

Sócrates Fraga da Costa-Neto ◽

...

Keyword(s):

Gene Flow ◽

Genetic Structure ◽

Host Specificity ◽

Atlantic Forest ◽

Host Species ◽

Population Genetic ◽

Fixation Index ◽

The South ◽

Genetic Structuring ◽

Morphometric Variation

Abstract Background: Population genetics of parasites may be influenced by host specificity, life-cycle, geographical distance, evolutionary history, and host-populations structure. The nematode Aspidodera raillieti infects different marsupial and rodent hosts in the Nearctic and Neotropical regions, implying a presumably significant gene flow among populations. However, niche diversification of A. raillieti main hosts in superimposed areas may provide conditions for population genetic structuring within this parasite species. We examined the genetic structuring of A. raillieti infecting three marsupial species co-occurring along South and Southeast Brazilian Atlantic Forest, a hotspot of biodiversity.Methods: We employed morphometric analyses and partial mitochondrial cytochrome c oxidase I gene sequences (MT-CO1) to characterize populations via phylogenetic and phylogeographic analyses.Results: Among 175 A. raillieti specimens recovered from marsupial hosts Didelphis aurita, D. albiventris, and Philander quica, we identified 99 MT-CO1 haplotypes forming four groups in phylogenetic trees and networks. Clades I and II encompassed parasites of D. albiventris from the South region, Clade III comprised parasites of D. aurita from the South and Southeast regions, and Clade IV encompassed parasites of D. aurita and D. albiventris from the South and Southeast regions and parasites of Philander quica from the South region. High genetic differentiation between clades, with a high fixation index and greater genetic variation in the analysis of molecular variance (AMOVA), indicated low gene flow between clades. Haplotypes shared among host species revealed a lack of host specificity. Significant correlation in the Mantel test, suggested parasite isolation by distance, although there was no evidence of geographic structure between populations. Negative values in neutrality tests for Clades III and IV suggested recent population expansion. Morphometric differentiation between A. raillieti specimens recovered from different host species, as well as from different localities, was more evident in males.Conclusion: The genetic structure of A. raillieti populations in the South and Southeast Atlantic Forest resulted from historical events rather than from current geographical distribution or host specificity. We also demonstrate morphometric variation associated with host species and localities, suggesting phenotypic plasticity to host attributes and to spatial variables.

Download Full-text

Genetic population structure of the monogenean parasite Gyrodactylus thymalli and its host European grayling (Thymallus thymallus) in a large Norwegian lake

Hydrobiologia ◽

10.1007/s10750-020-04431-7 ◽

2020 ◽

Author(s):

Ruben Alexander Pettersen ◽

Claudia Junge ◽

Kjartan Østbye ◽

Tor Atle Mo ◽

Leif Asbjørn Vøllestad

Keyword(s):

Genetic Structure ◽

Evolutionary Biology ◽

Isolation By Distance ◽

Genetic Structuring ◽

Thymallus Thymallus ◽

Homing Behavior ◽

Genetic Population ◽

Monogenean Parasite ◽

European Grayling ◽

Genetic Clusters

Abstract Understanding how populations are structured in space and time is a central question in evolutionary biology. Parasites and their hosts are assumed to evolve together, however, detailed understanding of mechanisms leading to genetic structuring of parasites and their hosts are lacking. As a parasite depends on its host, studying the genetic structure of both parasite and host can reveal important insights into these mechanisms. Here, genetic structure of the monogenean parasite Gyrodactylus thymalli and its host the European grayling (Thymallus thymallus) was investigated in 10 tributaries draining into the large Lake Mjøsa in Norway. The population genetic structure of spawning grayling was studied using microsatellite genotyping, while G. thymalli was studied by sequencing a mitochondrial DNA gene (dehydrogenase subunit 5). Two main genetic clusters were revealed in grayling, one cluster comprising grayling from the largest spawning population, while the remaining tributaries formed the second cluster. For both taxa, some genetic differentiation was observed among tributaries, but there was no clear isolation-by-distance signature. The structuring was stronger for the host than for the parasite. These results imply that moderate to high levels of gene flow occur among the sub-populations of both taxa. The high parasite exchange among tributaries could result from a lack of strong homing behavior in grayling as well as interactions among individual fish outside of the spawning season, leading to frequent mixing of both host and parasite.

Download Full-text