scholarly journals Spatial genetic structure across a hybrid zone between European rabbit subspecies

2014 ◽  
Author(s):  
Fernando Alda ◽  
Ignacio Doadrio
Keyword(s):  
Genetic Structure ◽  
Hybrid Zone ◽  
Spatial Genetic Structure ◽  
Local Level ◽  
Geographic Distance ◽  
Ecological Factors ◽  
Distribution Range ◽  
European Rabbit ◽  
Nuclear Markers ◽  
Genetic Groups

The Iberian Peninsula is the only region in the world where the two existing subspecies of the European rabbit (Oryctolagus cuniculus) naturally occur and hybridize. In this study we explore the relative roles of historical and contemporary processes in shaping the spatial genetic structure of the rabbit across its native distribution range, and how they differently affect each subspecies and the hybrid zone. For that purpose multilocus genotypes and mitochondrial DNA data were obtained for 771 rabbits across most of the species’ distribution range in Spain. Nuclear markers defined a hierarchical genetic structure firstly comprised by two genetic groups, largely congruent with the mitochondrial lineages and subspecies distributions (O. c. algirus and O. c. cuniculus), which were subsequently subdivided into seven genetic groups probably shaped by environmental or ecological factors. Geographic distance alone emerged as an important factor explaining genetic differentiation across the whole range, without the need to invoke for the effect for geographical barriers. Thus, when considering the overall genetic structure, differences at a local level seem to be of greater importance. The significantly positive spatial correlation up to a distance of only 100 km supported this hypothesis. However, northern populations of O. c. cuniculus showed more spatial genetic structure and differentiation than O. c. algirus, which could be due to local geographic barriers, limited resources, soil type and/or social behaviours limiting dispersal. The hybrid zone showed similar genetic structure to the southern populations but a larger introgression from the northern lineage genome. These differences have been attributed to selection against the hybrids rather than to behavioural differences between subspecies. Ultimately, the genetic structure of the rabbit in its native distribution range is the result of an ensemble of factors, from geographical and ecological, to behavioural and molecular, that hierarchically interact in time and space.

scholarly journals Spatial genetic structure across a hybrid zone between European rabbit subspecies

2014 ◽  
Author(s):  
Fernando Alda ◽  
Ignacio Doadrio
Keyword(s):  
Genetic Structure ◽  
Hybrid Zone ◽  
Spatial Genetic Structure ◽  
Local Level ◽  
Geographic Distance ◽  
Ecological Factors ◽  
Distribution Range ◽  
European Rabbit ◽  
Nuclear Markers ◽  
Genetic Groups

The Iberian Peninsula is the only region in the world where the two existing subspecies of the European rabbit (Oryctolagus cuniculus) naturally occur and hybridize. In this study we explore the relative roles of historical and contemporary processes in shaping the spatial genetic structure of the rabbit across its native distribution range, and how they differently affect each subspecies and the hybrid zone. For that purpose multilocus genotypes and mitochondrial DNA data were obtained for 771 rabbits across most of the species’ distribution range in Spain. Nuclear markers defined a hierarchical genetic structure firstly comprised by two genetic groups, largely congruent with the mitochondrial lineages and subspecies distributions (O. c. algirus and O. c. cuniculus), which were subsequently subdivided into seven genetic groups probably shaped by environmental or ecological factors. Geographic distance alone emerged as an important factor explaining genetic differentiation across the whole range, without the need to invoke for the effect for geographical barriers. Thus, when considering the overall genetic structure, differences at a local level seem to be of greater importance. The significantly positive spatial correlation up to a distance of only 100 km supported this hypothesis. However, northern populations of O. c. cuniculus showed more spatial genetic structure and differentiation than O. c. algirus, which could be due to local geographic barriers, limited resources, soil type and/or social behaviours limiting dispersal. The hybrid zone showed similar genetic structure to the southern populations but a larger introgression from the northern lineage genome. These differences have been attributed to selection against the hybrids rather than to behavioural differences between subspecies. Ultimately, the genetic structure of the rabbit in its native distribution range is the result of an ensemble of factors, from geographical and ecological, to behavioural and molecular, that hierarchically interact in time and space.

scholarly journals The Influence of Environmental Variation on the Genetic Structure of a Poison Frog Distributed Across Continuous Amazonian Rainforest

2020 ◽  
Vol 111 (5) ◽  
pp. 457-470 ◽  
Author(s):  
Anthony S Ferreira ◽  
Albertina P Lima ◽  
Robert Jehle ◽  
Miquéias Ferrão ◽  
Adam Stow
Keyword(s):  
Genetic Structure ◽  
Amazon Basin ◽  
Geographic Distance ◽  
Canopy Cover ◽  
Single Nucleotide ◽  
Poison Frog ◽  
Environmental Resistance ◽  
Genetic Groups ◽  
Allobates Femoralis ◽  
Phylogenetic Divergence

Abstract Biogeographic barriers such as rivers have been shown to shape spatial patterns of biodiversity in the Amazon basin, yet relatively little is known about the distribution of genetic variation across continuous rainforest. Here, we characterize the genetic structure of the brilliant-thighed poison frog (Allobates femoralis) across an 880-km-long transect along the Purus-Madeira interfluve south of the Amazon river, based on 64 individuals genotyped at 7609 single-nucleotide polymorphism (SNP) loci. A population tree and clustering analyses revealed 4 distinct genetic groups, one of which was strongly divergent. These genetic groups were concomitant with femoral spot coloration differences, which was intermediate within a zone of admixture between two of the groups. The location of these genetic groups did not consistently correspond to current ecological transitions between major forest types. A multimodel approach to quantify the relative influence of isolation-by-geographic distance (IBD) and isolation-by-environmental resistance (IBR) nevertheless revealed that, in addition to a strong signal of IBD, spatial genetic differentiation was explained by IBR primarily linked to dry season intensity (r2 = 8.4%) and canopy cover (r2 = 6.4%). We show significant phylogenetic divergence in the absence of obvious biogeographical barriers and that finer-scaled measures of genetic structure are associated with environmental variables also known to predict the density of A. femoralis.

scholarly journals Spatial Genetic Structure Within Two Contrasting Stands of Scots Pine (Pinus sylvestris L.)

2008 ◽  
Vol 57 (1-6) ◽  
pp. 193-202 ◽  
Author(s):  
I. J. Chybicki ◽  
A. Dzialuk ◽  
M. Trojankiewicz ◽  
M. Slawski ◽  
J. Burczyk
Keyword(s):  
Genetic Variation ◽  
Gene Flow ◽  
Genetic Structure ◽  
Pinus Sylvestris ◽  
Scots Pine ◽  
Spatial Genetic Structure ◽  
Nuclear Markers ◽  
Genetic Pool ◽  
Establishment History ◽  
Two Populations

AbstractWhen considering neutral nuclear markers, genetic differentiation of Scots pine (Pinus sylvestris L.) populations is known to be low. The homogeneity arises particularly as an effect of common ancestry in a recent evolutionary history as well as an extensive gene flow, especially through pollen. However, within populations several other forces may shape the spatial distribution of genetic variation, including establishment history, environmental and silvicultural selection. These local forces are known to produce non-random spatial patterns of genetic variation, however little is known on fine-scale spatial genetic structure of Scots pine. In this study, two stands of this species with different establishment histories, selected within one larger population located in northern Poland were genotyped and analysed for genetic variation and within-stand spatial genetic structure. Results revealed no differences in genetic variation, although stands are separated about 60 km, suggesting that the two populations share a common genetic pool. The spatial genetic structure in both stands was found to be slightly different and was attributed to differences in the mode of populations’ establishments. Finally, results confirmed that gene flow in Scots pine is extensive, causing genetic homogeneity within a single population.

Genome-Wide Screening of Aedes aegypti (Culicidae: Diptera) Populations From Northwestern Argentina: Active and Passive Dispersal Shape Genetic Structure

2020 ◽  
Vol 57 (6) ◽  
pp. 1930-1941
Author(s):  
Lucía Maffey ◽  
Maximiliano J Garzón ◽  
Viviana Confalonieri ◽  
Mariana M Chanampa ◽  
Esteban Hasson ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Aedes Aegypti ◽  
Isolation By Distance ◽  
Spatial Genetic Structure ◽  
Local Level ◽  
Regional Level ◽  
Northwestern Argentina ◽  
Entomological Survey ◽  
Genome Wide ◽  
High Prevalence

Abstract Aedes aegypti is the primary vector of arboviruses of great impact on human health. Our goal was to assess the spatial genetic structure of Ae. aegypti at the regional and local levels in Northwestern Argentina, an area with high prevalence of dengue fever. We analyzed 59 Ae. aegypti individuals collected from six locations in Northwestern Argentina using nuclear genome-wide Single Nucleotide Polymorphisms (SNPs) generated with double digest Restriction-site Associated DNA Sequencing. We also performed an entomological survey in 70 households in the cities of Orán and Tartagal. An analysis at the regional level indicated that the populations of Ae. aegypti in Northwestern Argentina are spatially structured and present a significant IBD pattern. Our results suggest that passive transport of eggs/immature stages, in both northward and southward directions, plays an important role in structuring Ae. aegypti populations at a regional scale and also as a source for the introduction of novel genetic variants through migration events into established populations. At a local level, we found neither spatial genetic structure nor significant isolation by distance (IBD) in Tartagal, indicating high gene flow within the city and active dispersal. In contrast, samples from Orán formed two clusters with a significant IBD pattern, although weaker than that at a regional level. Both populations showed signs of recent bottleneck events, probably coincident with past eradication campaigns. The entomological survey revealed a high prevalence of Ae. aegypti in both cities, although significantly higher in Tartagal.

Genetic diversity and gene flow patterns in two riverine plant species with contrasting life-history traits and distributions across a large inland floodplain

2020 ◽  
Vol 68 (5) ◽  
pp. 384
Author(s):  
William Higgisson ◽  
Dianne Gleeson ◽  
Linda Broadhurst ◽  
Fiona Dyer
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Genetic Structure ◽  
Water Resource ◽  
Isolation By Distance ◽  
Spatial Genetic Structure ◽  
Geographic Distance ◽  
Resource Development ◽  
Water Resource Development ◽  
Floodplain River

Gene flow is a key evolutionary driver of spatial genetic structure, reflecting demographic processes and dispersal mechanisms. Understanding how genetic structure is maintained across a landscape can assist in setting conservation objectives. In Australia, floodplains naturally experience highly variable flooding regimes that structure the vegetation communities. Flooding plays an important role, connecting communities on floodplains and enabling dispersal via hydrochory. Water resource development has changed the lateral-connectivity of floodplain-river systems. One possible consequence of these changes is reduced physical and subsequent genetic connections. This study aimed to identify and compare the population structure and dispersal patterns of tangled lignum (Duma florulenta) and river cooba (Acacia stenophylla) across a large inland floodplain using a landscape genetics approach. Both species are widespread throughout flood prone areas of arid and semiarid Australia. Tangled lignum occurs on floodplains while river cooba occurs along rivers. Leaves were collected from 144 tangled lignum plants across 10 sites and 84 river cooba plants across 6 sites, on the floodplain of the lower and mid Lachlan River, and the Murrumbidgee River, NSW. DNA was extracted and genotyped using DArTseq platforms (double digest RADseq). Genetic diversity was compared with floodplain-river connection frequency, and genetic distance (FST) was compared with river distance, geographic distance and floodplain-river connection frequency between sites. Genetic similarity increased with increasing floodplain-river connection frequency in tangled lignum but not in river cooba. In tangled lignum, sites that experience more frequent flooding had greater genetic diversity and were more genetically homogenous. There was also an isolation by distance effect where increasing geographic distance correlated with increasing genetic differentiation in tangled lignum, but not in river cooba. The distribution of river cooba along rivers facilitates regular dispersal of seeds via hydrochory regardless of river level, while the dispersal of seeds of tangled lignum between patches is dependent on flooding events. The genetic impact of water resource development may be greater for species which occur on floodplains compared with species along river channels.

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