scholarly journals Genetic structure of Octopus vulgaris around the Iberian Peninsula and Canary Islands as indicated by microsatellite DNA variation

2007 ◽  
Vol 65 (1) ◽  
pp. 12-16 ◽  
Author(s):  
C. Cabranes ◽  
P. Fernandez-Rueda ◽  
J. L. Martínez
Keyword(s):  
Genetic Structure ◽  
Iberian Peninsula ◽  
Canary Islands ◽  
Microsatellite Dna ◽  
Isolation By Distance ◽  
Octopus Vulgaris ◽  
Dna Variation ◽  
Management Perspective ◽  
Conservation Genetic ◽  
Distance Model

Abstract Cabranes, C., Fernandez-Rueda, P., and Martínez, J. L. 2008. Genetic structure of Octopus vulgaris around the Iberian Peninsula and Canary Islands as indicated by microsatellite DNA variation. – ICES Journal of Marine Science, 65: 12–16. Microsatellite DNA markers were used for a genetic study of Octopus vulgaris, a cephalopod species of great commercial interest to Spain and Portugal, and therefore subjected to intensive fishing. Improving the demographic knowledge of marine resources supports more-responsible management and conservation. Genetic variation at five microsatellite loci screened in six samples from NE Atlantic and Mediterranean coasts of the Iberian Peninsula was high [mean number of alleles = 18.3, mean He = 0.874]. Analysis of the microsatellites allowed significant subpopulation structure to be identified, consistent with an isolation-by-distance model for Atlantic populations. Differences between pairs of samples separated by <200 km were not significant. From a fisheries management perspective, the results support coordinated management of neighbouring stocks of O. vulgaris around the Iberian Peninsula.

The influence of Wisconsinan glaciation and contemporary stream hydrology on microsatellite DNA variation in rainbow trout (Oncorhynchus mykiss)

2010 ◽  
Vol 67 (6) ◽  
pp. 919-935 ◽  
Author(s):  
P. Tamkee ◽  
E. Parkinson ◽  
E. B. Taylor
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Microsatellite Dna ◽  
Isolation By Distance ◽  
Habitat Characteristics ◽  
Dna Variation ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Branching Points

Microsatellite DNA variation was examined in rainbow trout ( Oncorhynchus mykiss ) populations from throughout British Columbia, Canada, to address the roles of historical isolation, postglacial dispersal, and contemporary geomorphology in structuring genetic variation and differentiation. We detected signatures of historical isolation and postglacial recolonization in the form of “interior” and “coastal” population groupings, a decline in genetic variation as distance increased from putative glacial refugia, and different extents of isolation-by-distance in different regions. Rainbow trout populations were structured genetically into major regions and into smaller watersheds and then into drainages. Within drainages, high levels of dispersal and gene flow were inferred between geographically proximate and contiguous lakes. Elevation, stream branching points (nodes), fluvial distance, migration barriers, and stream and lake order influenced genetic diversity within, and differentiation among, populations. Habitat characteristics, particularly lake surface area and perimeter, were poor predictors of genetic variation. Although founder events and postglacial dispersal influenced broadscale patterns of genetic diversity in rainbow trout, our results suggest that contemporary factors can strongly modulate historical patterns.

scholarly journals Application of a random walk model to geographic distributions of animal mitochondrial DNA variation.

Genetics ◽  
1993 ◽  
Vol 135 (4) ◽  
pp. 1209-1220 ◽  
Author(s):  
J E Neigel ◽  
J C Avise
Keyword(s):  
Mitochondrial Dna ◽  
Isolation By Distance ◽  
Natural Populations ◽  
Data Sets ◽  
Long Distance ◽  
Dna Variation ◽  
Distance Model ◽  
Limited Dispersal ◽  
Geographic Distributions ◽  
Lineage Structure

Abstract In rapidly evolving molecules, such as animal mitochondrial DNA, mutations that delineate specific lineages may not be dispersed at sufficient rates to attain an equilibrium between genetic drift and gene flow. Here we predict conditions that lead to nonequilibrium geographic distributions of mtDNA lineages, test the robustness of these predictions and examine mtDNA data sets for consistency with our model. Under a simple isolation by distance model, the variance of an mtDNA lineage's geographic distribution is expected be proportional to its age. Simulation results indicated that this relationship is fairly robust. Analysis of mtDNA data from natural populations revealed three qualitative distributional patterns: (1) significant departure of lineage structure from equilibrium geographic distributions, a pattern exhibited in three rodent species with limited dispersal; (2) nonsignificant departure from equilibrium expectations, exhibited by two avian and two marine fish species with potentials for relatively long-distance dispersal; and (3) a progression from nonequilibrium distributions for younger lineages to equilibrium distributions for older lineages, a condition displayed by one surveyed avian species. These results demonstrate the advantages of considering mutation and genealogy in the interpretation of mtDNA geographic variation.

scholarly journals Population structure and geographically structured reproductive strategies of the haplodiplontic seaweed Dictyota dichotoma

2019 ◽  
Author(s):  
Frédérique Steen ◽  
Verlaque Marc ◽  
Sofie D’hondt ◽  
Christophe Vieira ◽  
Olivier De Clerck
Keyword(s):  
South Africa ◽  
Genetic Structure ◽  
Sexual Reproduction ◽  
Canary Islands ◽  
Isolation By Distance ◽  
Glacial Refugia ◽  
Population Diversity ◽  
Mediterranean Populations ◽  
Dictyota Dichotoma ◽  
Southern Norway

AbstractBoth mating system variation and the propensity of many seaweeds to reproduce both sexually and asexually, leave a strong imprint in the genetic structure of species. In this respect, we study the population genetic structure of Dictyota dichotoma, a common haplodiplont brown subtidal seaweed. This benthic species is widespread in the NE-Atlantic, from the Canary Islands and Mediterranean Sea to southern Norway, but lately populations have been reported from Argentina and South Africa. Phenology and reproduction of D. dichotoma was monitored year-round in four populations to investigate how the species has adapted to the steep thermal gradient in southern and northern ranges of its distribution. Thirteen microsatellites are developed in order to assess patterns of population diversity and structure across the biogeographic range, as shaped by past and present processes. Last, we assess the genetic structure of South African and South American populations and their relationship to the northern hemisphere populations.Throughout its range, D. dichotoma shows a varying reproductive effort, with sexual reproduction being more abundant in the northern range. In contrast, the Mediterranean populations show a clear sporophyte dominance, suggesting that sexual reproduction is not the prime mode of reproduction, and indicating that the species potentially resorts to other modes of propagation as for instance fragmentation or apospory.Genetic diversity is highest in the southern population decreasing gradually northward, indicative for a recolonization pattern after the demise of the last glacial maximum where these areas served as glacial refugia. European mainland populations show an isolation by distance pattern, while the population in the Canary Islands has its own genetic identity, being significantly diverged from the mainland population. Populations in South Africa and Argentina are seemingly introduced from mainland Europe, but no conclusion can be made on the exact timing of these introductions.

scholarly journals Population genetic structure of New Zealand blue cod (Parapercis colias) based on mitochondrial and microsatellite DNA markers

2021 ◽  
Author(s):  
◽  
Clare Louise Gebbie
Keyword(s):  
New Zealand ◽  
Genetic Structure ◽  
Population Genetic Structure ◽  
Dna Markers ◽  
Microsatellite Dna ◽  
Population Genetic ◽  
Current Knowledge ◽  
Isolation By Distance ◽  
Genetic Connectivity ◽  
Microsatellite Dna Markers

<p>Parapercis colias (blue cod) is an endemic temperate reef fish that supports an important commercial and recreational fishery in New Zealand. However, concerns have been raised about localized stock depletion, and multiple lines of evidence have suggested P. colias may form several biologically distinct populations within the New Zealand Exclusive Economic Zone. Mark and recapture studies along with otolith and stable isotope studies have indicated that individuals are sedentary with very limited movement beyond the scale of 10-20km. The primary goal of this research was to advance the current knowledge of P. colias population genetic structure. This information can be incorporated into stock assessment models with the aim of improving the management of the P. colias fishery. This study made use of 454 pyrosequencing technology to isolate and develop the first set of microsatellite DNA markers for P. colias. These seven microsatellite loci, along with mitochondrial control region sequences, were used to determine the levels of genetic variation and differentiation between sites around the New Zealand coastline, including the Chatham Islands.  Significant differentiation was observed between the Chatham Islands and mainland New Zealand sample sites, indicating that these two regions form distinct populations. Interpretation of the results for the mainland sites was more complex. Mitochondrial sequence data detected no significant pairwise differentiation between mainland sites, although a pattern of isolation-by-distance was observed. However, evidence for genetic differentiation among mainland sites was weak based on the microsatellite DNA analysis. Although pairwise Gѕт levels were significant in some sites, this was not reflected in principal component analysis or Bayesian structure analysis. It is likely that through long range dispersal, migration is at or above the threshold for genetic connectivity, but below a level necessary for demographic connectivity. This is indicated by both the genetic structure reported here, along with previous studies showing limited dispersal of P. colias.</p>

Comparative Genetic Diversity and Structure of the Rhus Gall Aphid Schlechtendalia Chinensis and Its Host-Plant Rhus Chinensis

2021 ◽  
Author(s):  
Zhu Ren ◽  
Hong He ◽  
Yang Zhang ◽  
Xu Su
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Host Plant ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
Isolation By Distance ◽  
Geographic Distance ◽  
Rhus Chinensis ◽  
Genetic Diversity And Structure ◽  
Distance Model

Abstract Studying the population genetic structure of both parasites and their host-plants is expected to yield new valuable insights into their coevolution. In this study, we examined and compared the population genetic diversity and structure of 12 populations of the Rhus gall aphid, Schlechtendalia chinensis, and its host-plant, Rhus chinensis, using amplified fragment length polymorphism (AFLP) markers. AMOVA analysis showed that the genetic variance of the aphid and its host-plant were both higher within populations compared to that among them, suggesting that a co-evolutionary history has yielded similar patterns of population genetic structure. We did not detect significant correlation between genetic and geographic distance for either the aphid or host-plant populations, therefore rejecting an isolation by distance model for the demographic histories of the two species. However, our results appeared to suggest that genetically diverse host -plant Rhus populations correlated to similarly genetically diverse populations of gall aphid parasites.

scholarly journals Genetic structure and diversity of the selfing model grassBrachypodium stacei(Poaceae) in Western Mediterranean: out of the Iberian Peninsula and into the islands

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2407 ◽  
Author(s):  
Valeriia Shiposha ◽  
Pilar Catalán ◽  
Marina Olonova ◽  
Isabel Marques
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Genetic Structure ◽  
Iberian Peninsula ◽  
Canary Islands ◽  
Population Genetic ◽  
Western Mediterranean ◽  
Life Cycles ◽  
Detailed Knowledge ◽  
Genome Wide Association Studies

Annual Mediterranean species of the genusBrachypodiumare promising model plants for energy crops since their selfing nature and short-life cycles are an advantage in breeding programs. The false brome,B. distachyon, has already been sequenced and new genomic initiatives have triggered the de-novo genome sequencing of its close relatives such asB. stacei, a species that was until recently mistaken forB. distachyon. However, the success of these initiatives hinges on detailed knowledge about the distribution of genetic variation within and among populations for the effective use of germplasm in a breeding program. Understanding population genetic diversity and genetic structure is also an important prerequisite for designing effective experimental populations for genomic wide studies. However, population genetic data are still limited inB. stacei. We therefore selected and amplified 10 nuclear microsatellite markers to depict patterns of population structure and genetic variation among 181 individuals from 19 populations ofB. staceioccurring in its predominant range, the western Mediterranean area: mainland Iberian Peninsula, continental Balearic Islands and oceanic Canary Islands. Our genetic results support the occurrence of a predominant selfing system with extremely high levels of homozygosity across the analyzed populations. Despite the low level of genetic variation found, two different genetic clusters were retrieved, one clustering all SE Iberian mainland populations and the island of Minorca and another one grouping all S Iberian mainland populations, the Canary Islands and all Majorcan populations except one that clustered with the former group. These results, together with a high sharing of alleles (89%) suggest different colonization routes from the mainland Iberian Peninsula into the islands. A recent colonization scenario could explain the relatively low levels of genetic diversity and low number of alleles found in the Canary Islands populations while older colonization events are hypothesized to explain the high genetic diversity values found in the Majorcan populations. Our study provides widely applicable information about geographical patterns of genetic variation inB. stacei. Among others, the genetic pattern and the existence of local alleles will need to be adequately reflected in the germplasm collection ofB. staceifor efficient genome wide association studies.

scholarly journals Population genetic structure of New Zealand blue cod (Parapercis colias) based on mitochondrial and microsatellite DNA markers

2021 ◽  
Author(s):  
◽  
Clare Louise Gebbie
Keyword(s):  
New Zealand ◽  
Genetic Structure ◽  
Population Genetic Structure ◽  
Dna Markers ◽  
Microsatellite Dna ◽  
Population Genetic ◽  
Current Knowledge ◽  
Isolation By Distance ◽  
Genetic Connectivity ◽  
Microsatellite Dna Markers

<p>Parapercis colias (blue cod) is an endemic temperate reef fish that supports an important commercial and recreational fishery in New Zealand. However, concerns have been raised about localized stock depletion, and multiple lines of evidence have suggested P. colias may form several biologically distinct populations within the New Zealand Exclusive Economic Zone. Mark and recapture studies along with otolith and stable isotope studies have indicated that individuals are sedentary with very limited movement beyond the scale of 10-20km. The primary goal of this research was to advance the current knowledge of P. colias population genetic structure. This information can be incorporated into stock assessment models with the aim of improving the management of the P. colias fishery. This study made use of 454 pyrosequencing technology to isolate and develop the first set of microsatellite DNA markers for P. colias. These seven microsatellite loci, along with mitochondrial control region sequences, were used to determine the levels of genetic variation and differentiation between sites around the New Zealand coastline, including the Chatham Islands.  Significant differentiation was observed between the Chatham Islands and mainland New Zealand sample sites, indicating that these two regions form distinct populations. Interpretation of the results for the mainland sites was more complex. Mitochondrial sequence data detected no significant pairwise differentiation between mainland sites, although a pattern of isolation-by-distance was observed. However, evidence for genetic differentiation among mainland sites was weak based on the microsatellite DNA analysis. Although pairwise Gѕт levels were significant in some sites, this was not reflected in principal component analysis or Bayesian structure analysis. It is likely that through long range dispersal, migration is at or above the threshold for genetic connectivity, but below a level necessary for demographic connectivity. This is indicated by both the genetic structure reported here, along with previous studies showing limited dispersal of P. colias.</p>

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