scholarly journals Genetic diversity and population structure of Culex modestus across Europe: does recent appearance in the United Kingdom reveal a tendency for geographical spread?

2019 ◽  
Vol 34 (1) ◽  
pp. 86-96 ◽  
Author(s):  
L. M. Hernández‐Triana ◽  
V. A. Brugman ◽  
P. Pramual ◽  
E. Barrero ◽  
N. I. Nikolova ◽  
...  
2017 ◽  
Vol 27 (4) ◽  
pp. 839-845 ◽  
Author(s):  
Morten Tange Olsen ◽  
Valentina Islas ◽  
Jeff A. Graves ◽  
Aubrie Onoufriou ◽  
Cecile Vincent ◽  
...  

1998 ◽  
Vol 88 (5) ◽  
pp. 537-543 ◽  
Author(s):  
D. Nicol ◽  
K.F. Armstrong ◽  
S.D. Wratten ◽  
P.J. Walsh ◽  
N.A. Straw ◽  
...  

AbstractThe green spruce aphid Elatobium abietinum (Walker) is an introduced pest in the United Kingdom and more recently in New Zealand. In outbreak years this aphid can cause severe defoliation and sometimes death of spruce trees (Picea spp.). As chemical control is not financially viable, other options including host-plant resistance and biological control are currently being investigated. An understanding of the genetic variation of this pest is imperative in fully utilizing these control strategies. To examine this, E. abietinum was collected from Sitka spruce Picea sitchensis from four locations in the UK that were up to 240 km apart. Of these, 40 aphids were analysed via two alternative polymerase chain reaction (PCR) analyses using primer pairs. The first analysis used 10-mer random primers, whilst the second analysis used primers designed to amplify across the intergenic spacer region of rDNA. Combining results from the two analyses allowed the 40 UK aphids to be separated into 28 different genotypes. The genetic variation was also high within each UK site, with 77 to 89% of the aphids sampled being of a different genotype. The two PCR analyses were subsequently used to examine 40 aphids across six sites in New Zealand up to 1200 km apart. No genetic variation was identified. Further analysis of several of these New Zealand aphids with 87 individual 10-mer primers and two polymerase enzymes, still did not detect any genetic variation. The high degree of genotypic diversity in the UK populations was presumably due to a longer period of establishment, multiple introductions and/or sexual reproduction. The contrasting lack of genetic variation in New Zealand populations was probably due to a very limited founder population, continued isolation and lack of sexual reproduction. Reduced genetic diversity can seriously decrease the ability of a population to adapt to control strategies. Therefore the durability of certain control methods may be more readily maintained in such an isolated population in New Zealand.


2007 ◽  
Vol 81 (23) ◽  
pp. 13050-13056 ◽  
Author(s):  
Robert J. Gifford ◽  
Tulio de Oliveira ◽  
Andrew Rambaut ◽  
Oliver G. Pybus ◽  
David Dunn ◽  
...  

ABSTRACT With ongoing generation of viral genetic diversity and increasing levels of migration, the global human immunodeficiency virus type 1 (HIV-1) epidemic is becoming increasingly heterogeneous. In this study, we investigate the epidemiological characteristics of 5,675 HIV-1 pol gene sequences sampled from distinct infections in the United Kingdom. These sequences were phylogenetically analyzed in conjunction with 976 complete-genome and 3,201 pol gene reference sequences sampled globally and representing the broad range of HIV-1 genetic diversity, allowing us to estimate the probable geographic origins of the various strains present in the United Kingdom. A statistical analysis of phylogenetic clustering in this data set identified several independent transmission chains within the United Kingdom involving recently introduced strains and indicated that strains more commonly associated with infections acquired heterosexually in East Africa are spreading among men who have sex with men. Coalescent approaches were also used and indicated that the transmission chains that we identify originated in the late 1980s to early 1990s. Similar changes in the epidemiological structuring of HIV epidemics are likely to be taking in place in other industrialized nations with large immigrant populations. The framework implemented here takes advantage of the vast amount of routinely generated HIV-1 sequence data and can provide epidemiological insights not readily obtainable through standard surveillance methods.


2021 ◽  
Vol 101 (2) ◽  
pp. 233-247
Author(s):  
Simone Mordue ◽  
James Aegerter ◽  
Aileen Mill ◽  
Deborah A. Dawson ◽  
Carolina Crepaldi ◽  
...  

AbstractThere have been significant declines in population numbers of many bat species in the United Kingdom, including Natterer’s bats Myotis nattereri, over the last century, largely due to anthropogenic changes. The philopatry, which temperate-zone bats often exhibit to their natal landscapes, in combination with anthropogenic threats, can lead to fragmentation, isolation and sub-division of populations. This may result in bottlenecks and declines in genetic diversity. Multi-scaled research is required to disentangle how the variation in the physical traits of bat species (e.g. affecting flight), as well as their social and behavioural traits (e.g. community size, migration, breeding systems), may affect the genetic health of populations and provide a potential buffer against fragmentation. We used microsatellite markers to characterise the genetic diversity and population structure present in Natterer’s bat colonies to determine whether summer roosting bat colonies were spatially differentiated or part of a meta-population. Analyses of population structure and measures of genetic relatedness suggest spatially differentiated populations of bats exhibit long term site fidelity to summer roosting sites, whilst high genetic diversity at sites indicates gene exchange occurs via swarming sites. Natterer’s bats in northern England may travel greater distances to swarming sites than has been previously documented.


2009 ◽  
pp. 1-6 ◽  
Author(s):  
Nishan Fernando ◽  
Gordon Prescott ◽  
Jennifer Cleland ◽  
Kathryn Greaves ◽  
Hamish McKenzie

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