Gene flow within the M evolutionary lineage ofApis mellifera: role of the Pyrenees, isolation by distance and post-glacial re-colonization routes in the western Europe

Apidologie ◽  
2007 ◽  
Vol 38 (2) ◽  
pp. 141-155 ◽  
Author(s):  
Irati Miguel ◽  
Mikel Iriondo ◽  
Lionel Garnery ◽  
Walter S. Sheppard ◽  
Andone Estonba
Keyword(s):  
Gene Flow ◽  
Western Europe ◽  
Isolation By Distance ◽  
Colonization Routes ◽  
Evolutionary Lineage

scholarly journals Population structure, adaptation and divergence of the meadow spittlebug, Philaenus spumarius (Hemiptera, Aphrophoridae), revealed by genomic and morphological data

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11425
Author(s):  
Sofia G. Seabra ◽  
Ana S.B. Rodrigues ◽  
Sara E. Silva ◽  
Ana Carina Neto ◽  
Francisco Pina-Martins ◽  
...  
Keyword(s):  
Gene Flow ◽  
Western Europe ◽  
Population Genomics ◽  
Isolation By Distance ◽  
Plant Diseases ◽  
Morphological Data ◽  
Philaenus Spumarius ◽  
Mitochondrial Coi ◽  
Temperature And Precipitation ◽  
Genome Wide

Understanding patterns of population differentiation and gene flow in insect vectors of plant diseases is crucial for the implementation of management programs of disease. We investigated morphological and genome-wide variation across the distribution range of the spittlebug Philaenus spumarius (Linnaeus, 1758) (Hemiptera, Auchenorrhyncha, Aphrophoridae), presently the most important vector of the plant pathogenic bacterium Xylella fastidiosa Wells et al., 1987 in Europe. We found genome-wide divergence between P. spumarius and a very closely related species, P. tesselatus Melichar, 1899, at RAD sequencing markers. The two species may be identified by the morphology of male genitalia but are not differentiated at mitochondrial COI, making DNA barcoding with this gene ineffective. This highlights the importance of using integrative approaches in taxonomy. We detected admixture between P. tesselatus from Morocco and P. spumarius from the Iberian Peninsula, suggesting gene-flow between them. Within P. spumarius, we found a pattern of isolation-by-distance in European populations, likely acting alongside other factors restricting gene flow. Varying levels of co-occurrence of different lineages, showing heterogeneous levels of admixture, suggest other isolation mechanisms. The transatlantic populations of North America and Azores were genetically closer to the British population analyzed here, suggesting an origin from North-Western Europe, as already detected with mitochondrial DNA. Nevertheless, these may have been produced through different colonization events. We detected SNPs with signatures of positive selection associated with environmental variables, especially related to extremes and range variation in temperature and precipitation. The population genomics approach provided new insights into the patterns of divergence, gene flow and adaptation in these spittlebugs and led to several hypotheses that require further local investigation.

scholarly journals A regression approach to estimate the relative roles of pollen- versus seed-mediated gene flow under an isolation by distance model

2018 ◽  
Vol 67 (1) ◽  
pp. 41-50
Author(s):  
M. E. Barrandeguy ◽  
M. V. García
Keyword(s):  
Gene Flow ◽  
Empirical Data ◽  
Isolation By Distance ◽  
Island Model ◽  
Distribution Model ◽  
Data Set ◽  
Versus Gene ◽  
Seed Dispersion ◽  
Distance Model

Abstract In the present work, a new estimator to be known as rIBD is pro­posed. The proposed estimator indirectly quantifies the relati­ve role of gene flow mediated by pollen in relation to the gene flow mediated by seeds in hermaphrodite angiosperm species when an isolation by distance model is assumed. The proposed estimator complements the well-known estimator proposed by Ennos, which is appropriate for studies under the island model. In the present work, the proposed rIBD index was used to analyze microsatellite data from uni- and biparentally inherited genomes generated by simulations, as well as for the analysis of an empirical data set obtained from public databases of forest tree species. The differences in median values of the pro­posed rIBD index for simulated data using the Stepping Stone Model and Truncated Pareto Distribution Model coincided with the magnitude expected in terms of differences between levels of pollen and seed dispersion previously established in the simulations. In empirical data, the proposed rIBD index shows lower levels of gene flow by seed versus gene flow by pollen, the ratio between them being three times lower than the ratio obtained by the Ennos index estimated under the island model. From the analyses carried out, it is feasible to consider the rIBD index as a suitable estimator of the role of gene flow by seeds in relation to gene flow by pollen under iso­lation by distance.

EPIZOOTOLOGICAL FEATURES OF MODERN CATTLE LEUKEMIA

1970 ◽  
pp. 53-58
Author(s):  
V. V. Makarov ◽  
D. A. Lozovoy
Keyword(s):  
Dairy Cattle ◽  
Western Europe ◽  
Control Programs ◽  
Foreign Countries ◽  
Negative Order ◽  
Dairy Cattle Breeding ◽  
The Usa ◽  
Epizootic Process ◽  
National Programs

  Enzootic bovine leucosis (EBL) has been known for more than a century and a half. Its occurrence and registration may have historically been associated with intensive breeding of dairy cattle in Western Europe to increase target productivity. It is known that any limiting intervention in the nature of the animal organism is always accompanied by an uncontrolled and unpredictable change in the genotype of a wider range than the required, particularly negative order. In particular, a decrease in the resistance to macroorganisms and the possibility of the new diseases emergence, including infectious ones (for example, immunodeficiencies such as BLAD syndrome of black-motley cattle and stress syndrome in pigs, the occurrence of scrapie and other slow sheep infections). In the last two decades of the last century, in many disadvantaged countries, primarily Western European, national programs for the eradication of EBL have been developed and subsequently successfully implemented. First of all the motivation was the economy of dairy cattle breeding (mainly the extension of productive age, as well as the tightening of requirements in international trade in cattle and bull products, breeding, pricing, etc.). In an analytical article are reviewed the elements of epizootology of EBL in the foreign countries with special attention to the situation in the USA, scenarios of various control programs, and promising methods for assessing the role of infected animals in the epizootic process. A critical assessment of the problem of EBL in the Russian Federation is given, the reasons for the ineffectiveness of against leucosis measures are discussed.

Conclusion

2018 ◽  
Author(s):  
Ildar Garipzanov
Keyword(s):  
Cultural History ◽  
Middle Ages ◽  
Late Antiquity ◽  
Western Europe ◽  
Dominant Role ◽  
Ninth Century ◽  
Sources Of Authority ◽  
History Of ◽  
Historical Periods

The concluding chapter highlights how the cultural history of graphic signs of authority in late antiquity and the early Middle Ages encapsulated the profound transformation of political culture in the Mediterranean and Europe from approximately the fourth to ninth centuries. It also reflects on the transcendent sources of authority in these historical periods, and the role of graphic signs in highlighting this connection. Finally, it warns that, despite the apparent dominant role of the sign of the cross and cruciform graphic devices in providing access to transcendent protection and support in ninth-century Western Europe, some people could still employ alternative graphic signs deriving from older occult traditions in their recourse to transcendent powers.

scholarly journals Population genetics of Aedes albopictus (Diptera: Culicidae) in its native range in Lao People’s Democratic Republic

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Maysa Tiemi Motoki ◽  
Dina Madera Fonseca ◽  
Elliott Frederic Miot ◽  
Bruna Demari-Silva ◽  
Phoutmany Thammavong ◽  
...  
Keyword(s):  
Population Structure ◽  
Gene Flow ◽  
Aedes Albopictus ◽  
Isolation By Distance ◽  
Genetic Locus ◽  
Lao Pdr ◽  
Phylogenetic Network ◽  
Population Expansion ◽  
Recent Population Expansion ◽  
The Usa

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.

scholarly journals Premating barriers in young sympatric snail species

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Arina L. Maltseva ◽  
Marina A. Varfolomeeva ◽  
Arseniy A. Lobov ◽  
Polina O. Tikanova ◽  
Egor A. Repkin ◽  
...  
Keyword(s):  
Gene Flow ◽  
Snail Species ◽  
Sympatric Populations ◽  
Gastropod Species ◽  
Shell Size ◽  
Closely Related Species ◽  
Partial Canonical Correspondence Analysis ◽  
In The Wild ◽  
Isolation Index

AbstractSympatric coexistence of recently diverged species raises the question of barriers restricting the gene flow between them. Reproductive isolation may be implemented at several levels, and the weakening of some, e.g. premating, barriers may require the strengthening of the others, e.g. postcopulatory ones. We analysed mating patterns and shell size of mates in recently diverged closely related species of the subgenus Littorina Neritrema (Littorinidae, Caenogastropoda) in order to assess the role of premating reproductive barriers between them. We compared mating frequencies observed in the wild with those expected based on relative densities using partial canonical correspondence analysis. We introduced the fidelity index (FI) to estimate the relative accuracy of mating with conspecific females and precopulatory isolation index (IPC) to characterize the strength of premating barriers. The species under study, with the exception of L. arcana, clearly demonstrated preferential mating with conspecifics. According to FI and IPC, L. fabalis and L. compressa appeared reliably isolated from their closest relatives within Neritrema. Individuals of these two species tend to be smaller than those of the others, highlighting the importance of shell size changes in gastropod species divergence. L. arcana males were often found in pairs with L. saxatilis females, and no interspecific size differences were revealed in this sibling species pair. We discuss the lack of discriminative mate choice in the sympatric populations of L. arcana and L. saxatilis, and possible additional mechanisms restricting gene flow between them.

scholarly journals Molecular Signatures of Reticulate Evolution within the Complex of European Pine Taxa

Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 489
Author(s):  
Bartosz Łabiszak ◽  
Witold Wachowiak
Keyword(s):  
Gene Flow ◽  
Reticulate Evolution ◽  
Modeling Framework ◽  
Closely Related Species ◽  
Interspecific Gene Flow ◽  
Nucleotide Sequence Variation ◽  
History Of ◽  
Best Fitting ◽  
Species Integrity

Speciation mechanisms, including the role of interspecific gene flow and introgression in the emergence of new species, are the major focus of evolutionary studies. Inference of taxonomic relationship between closely related species may be challenged by past hybridization events, but at the same time, it may provide new knowledge about mechanisms responsible for the maintenance of species integrity despite interspecific gene flow. Here, using nucleotide sequence variation and utilizing a coalescent modeling framework, we tested the role of hybridization and introgression in the evolutionary history of closely related pine taxa from the Pinus mugo complex and P. sylvestris. We compared the patterns of polymorphism and divergence between taxa and found a great overlap of neutral variation within the P. mugo complex. Our phylogeny reconstruction indicated multiple instances of reticulation events in the past, suggesting an important role of interspecific gene flow in the species divergence. The best-fitting model revealed P. mugo and P. uncinata as sister species with basal P. uliginosa and asymmetric migration between all investigated species after their divergence. The magnitude of interspecies gene flow differed greatly, and it was consistently stronger from representatives of P. mugo complex to P. sylvestris than in the opposite direction. The results indicate the prominent role of reticulation evolution in those forest trees and provide a genetic framework to study species integrity maintained by selection and local adaptation.

Introgression between non-sister species of honeyeaters (Aves: Meliphagidae) several million years after speciation

2019 ◽  
Vol 128 (3) ◽  
pp. 583-591
Author(s):  
Leo Joseph ◽  
Alex Drew ◽  
Ian J Mason ◽  
Jeffrey L Peters
Keyword(s):  
Gene Flow ◽  
Reproductive Isolation ◽  
Sex Chromosomes ◽  
Common Ancestor ◽  
Sister Species ◽  
Species Boundaries ◽  
North Eastern ◽  
The City

Abstract We reassessed whether two parapatric non-sister Australian honeyeater species (Aves: Meliphagidae), varied and mangrove honeyeaters (Gavicalis versicolor and G. fasciogularis, respectively), that diverged from a common ancestor c. 2.5 Mya intergrade in the Townsville area of north-eastern Queensland. Consistent with a previous specimen-based study, by using genomics methods we show one-way gene flow for autosomal but not Z-linked markers from varied into mangrove honeyeaters. Introgression barely extends south of the area of parapatry in and around the city of Townsville. While demonstrating the long-term porosity of species boundaries over several million years, our data also suggest a clear role of sex chromosomes in maintaining reproductive isolation.

Sign in / Sign up

Export Citation Format

Share Document