scholarly journals Population structure of the squid Doryteuthis pealeii on the eastern coast of the USA: Comment on Shaw et al. (2010)

2012 ◽  
Vol 450 ◽  
pp. 281-283 ◽  
Author(s):  
G Gerlach ◽  
KC Buresch ◽  
RT Hanlon
2012 ◽  
Vol 450 ◽  
pp. 285-287 ◽  
Author(s):  
PW Shaw ◽  
L Hendrickson ◽  
NJ McKeown ◽  
T Stonier ◽  
MJ Naud ◽  
...  

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Maysa Tiemi Motoki ◽  
Dina Madera Fonseca ◽  
Elliott Frederic Miot ◽  
Bruna Demari-Silva ◽  
Phoutmany Thammavong ◽  
...  

Abstract Background The Asian tiger mosquito, Aedes (Stegomyia) albopictus (Skuse) is an important worldwide invasive species and can be a locally important vector of chikungunya, dengue and, potentially, Zika. This species is native to Southeast Asia where populations thrive in both temperate and tropical climates. A better understanding of the population structure of Ae. albopictus in Lao PDR is very important in order to support the implementation of strategies for diseases prevention and vector control. In the present study, we investigated the genetic variability of Ae. albopictus across a north-south transect in Lao PDR. Methods We used variability in a 1337-bp fragment of the mitochondrial cytochrome c oxidase subunit 1 gene (cox1), to assess the population structure of Ae. albopictus in Lao PDR. For context, we also examined variability at the same genetic locus in samples of Ae. albopictus from Thailand, China, Taiwan, Japan, Singapore, Italy and the USA. Results We observed very high levels of genetic polymorphism with 46 novel haplotypes in Ae. albopictus from 9 localities in Lao PDR and Thailand populations. Significant differences were observed between the Luangnamtha population and other locations in Lao PDR. However, we found no evidence of isolation by distance. There was overall little genetic structure indicating ongoing and frequent gene flow among populations or a recent population expansion. Indeed, the neutrality test supported population expansion in Laotian Ae. albopictus and mismatch distribution analyses showed a lack of low frequency alleles, a pattern often seen in bottlenecked populations. When samples from Lao PDR were analyzed together with samples from Thailand, China, Taiwan, Japan, Singapore, Italy and the USA, phylogenetic network and Bayesian cluster analysis showed that most populations from tropical/subtropical regions are more genetically related to each other, than populations from temperate regions. Similarly, most populations from temperate regions are more genetically related to each other, than those from tropical/subtropical regions. Conclusions Aedes albopictus in Lao PDR are genetically related to populations from tropical/subtropical regions (i.e. Thailand, Singapore, and California and Texas in the USA). The extensive gene flow among locations in Lao PDR indicates that local control is undermined by repeated introductions from untreated sites.


PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0258181
Author(s):  
Stéphane de Palmas ◽  
Derek Soto ◽  
Ming-Jay Ho ◽  
Vianney Denis ◽  
Chaolun Allen Chen

Mesophotic habitats could be sheltered from natural and anthropogenic disturbances and act as reproductive refuges, providing propagules to replenish shallower populations. Molecular markers can be used as proxies evaluating the connectivity and inferring population structure and larval dispersal. This study characterizes population structure as well as horizontal and vertical genetic connectivity of the broadcasting coral Pocillopora verrucosa from Ludao, a small oceanic island off the eastern coast of Taiwan. We genotyped 75 P. verrucosa specimens from three sites (Gongguan, Dabaisha, and Guiwan) at three depth ranges (Shallow: 7–15 m, Mid-depth: 23–30 m, and Deep: 38–45 m), spanning shallow to upper mesophotic coral reefs, with eight microsatellite markers. F-statistics showed a moderate differentiation (FST = 0.106, p<0.05) between two adjacent locations (Dabaisha 23–30 and Dabaisha 38–45 m), but no differentiation elsewhere, suggesting high levels of connectivity among sites and depths. STRUCTURE analysis showed no genetic clustering among sites or depths, indicating that all Pocillopora individuals could be drawn from a single panmictic population. Simulations of recent migration assigned 30 individuals (40%) to a different location from where they were collected. Among them, 1/3 were assigned to deeper locations, 1/3 to shallower populations and 1/3 were assigned to the right depth but a different site. These results suggest high levels of vertical and horizontal connectivity, which could enhance the recovery of P. verrucosa following disturbances around Ludao, a feature that agrees with demographic studies portraying this species as an opportunistic scleractinian.


2021 ◽  
Author(s):  
Andrii Gryganskyi ◽  
Jacob Golan ◽  
Ann E. Hajek

Populations of the entomopathogenic fungus Batkoa major were analyzed using sequences of four genomic regions and evaluated in relation to their genetic diversity, insect hosts and collection site. This entomophthoralean pathogen killed numerous insect species from 23 families and five orders in two remote locations during 2019. The host list of this biotrophic pathogen contains flies, true bugs, butterflies and moths, beetles, and barkflies. Among the infected bugs (Order Hemiptera), the spotted lanternfly ( Lycorma delicatula ) is a new invasive planthopper pest of various woody plants that was introduced to the USA from Eastern Asia. A high degree of clonality occurred in the studied populations and high gene flow was revealed using four molecular loci for the analysis of population structure. We did not detect any segregation in the population regarding host affiliation (by family or order), or collection site. This is the first description of population structure of a biotrophic fungus-generalist in the entomopathogenic Order Entomophthorales. This analysis aimed to better understand the potential populations of entomopathogen-generalists infecting emerging invasive hosts in new ecosystems.


2021 ◽  
pp. 097359842110351
Author(s):  
Narottam Gaan

In the aftermath glow of the end of the Cold War was seen faintly the swaggering footsteps of a triumphant USA ready to architect a new world attic with the mortars and bricks of its own politico-economic ideology. But the engendered vibe and euphoria bedecking America proved to be ephemeral with its dismal economic straits, failure of overseas military adventurism, terrorist attack on its trade center and loosening grip over global events, rise of other powers, and unwillingness of the world to kowtow to American lines. China, in contrast, showed ascendancy in economic growth, rising productive forces, military modernization, and ambitious global designs, giving rise to the neorealist zero-sum understanding that eclipsing USA has lent to the ascent of China in the global scene. But this kind of analysis is mostly founded on traditional paradigm of politico-military and economic power. What is primarily ignored or marginalized in the analysis of power structure in global politics is the demography, that is, aging population structure. The present article focuses on aging population structure of the USA, China and other great powers and tries to challenge this traditionally ingrained understanding of power structure and holds on to the view that if the current population structure is any indication, America will rule the roost in global politics.


1999 ◽  
Vol 135 (3) ◽  
pp. 399-405 ◽  
Author(s):  
N. V. Schizas ◽  
G. T. Street ◽  
B. C. Coull ◽  
G. T. Chandler ◽  
J. M. Quattro

Nature ◽  
1976 ◽  
Vol 263 (5577) ◽  
pp. 491-492 ◽  
Author(s):  
BRUCE P. HAYDEN
Keyword(s):  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jeewan Pandey ◽  
Douglas C. Scheuring ◽  
Jeffrey W. Koym ◽  
Joseph Coombs ◽  
Richard G. Novy ◽  
...  

AbstractKnowledge regarding genetic diversity and population structure of breeding materials is essential for crop improvement. The Texas A&M University Potato Breeding Program has a collection of advanced clones selected and maintained in-vitro over a 40-year period. Little is known about its genetic makeup and usefulness for the current breeding program. In this study, 214 potato clones were genotyped with the Infinium Illumina 22 K V3 Potato Array. After filtering, a total of 10,106 single nucleotide polymorphic (SNP) markers were used for analysis. Heterozygosity varied by SNP, with an overall average of 0.59. Three groups of tetraploid clones primarily based on potato market classes, were detected using STRUCTURE software and confirmed by discriminant analysis of principal components. The highest coefficient of differentiation observed between the groups was 0.14. Signatures of selection were uncovered in genes controlling potato flesh and skin color, length of plant cycle and tuberization, and carbohydrate metabolism. A core set of 43 clones was obtained using Core Hunter 3 to develop a sub-collection that retains similar genetic diversity as the whole population, minimize redundancies, and facilitates long-term conservation of genetic resources. The comprehensive molecular characterization of our breeding clone bank collection contributes to understanding the genetic diversity of existing potato resources. This analysis could be applied to other breeding programs and assist in the selection of parents, fingerprinting, protection, and management of the breeding collections.


2021 ◽  
Author(s):  
Milan Řezáč ◽  
Steven Tessler ◽  
Petr Heneberg ◽  
Ivalú Macarena Ávila Herrera ◽  
Nela Gloríková ◽  
...  

The Mygalomorph spiders of the family Atypidae are among the most archaic spiders. The genus Atypus Latreille, 1804 occurs in Eurasia and northern Africa, with a single enigmatic species, Atypus snetsingeri Sarno, 1973, restricted to a small area in southeastern Pennsylvania in Eastern USA. This study was undertaken to learn more about genetics of that species, its habitat requirements and natural history. A close relationship to European species could be assumed based on A. snetsingeri’s occurrence on the eastern coast of the USA, however molecular markers (CO1 sequences) confirmed that A. snetsingeri is identical with Atypus karschi Dönitz, 1887 native to East Asia; it is an introduced species. The specific epithet snetsingeri is therefore relegated to a junior synonym of A. karschi . The karyotype of A. karschi has 42 chromosomes in females and 41 in males (X0 sex chromosome system). Chromosomes were metacentric except for one pair, which exhibited submetacentric morphology. In Pennsylvania the above-ground webs are usually vertical and attached to the base of bushes, trees, or walls, although some webs are oriented horizontally near the ground. It was found in a variety of habitats from forests to suburban shrubbery, and over a wide range of soil humidity and physical parameters. Prey include millipedes, snails, woodlice, carabid beetles and earthworms. The number of juveniles in excavated female webs ranged from 70 to 201. Atypus karschi is the first known case of an introduced purse-web spider. It is rarely noticed but well-established within its range in southeastern Pennsylvania.


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