Connectivity among populations of pygmy whitefish (Prosopium coulterii) in northwestern North America inferred from microsatellite DNA analyses

2011 ◽  
Vol 89 (4) ◽  
pp. 255-266 ◽  
Author(s):  
E.B. Taylor ◽  
J.L. Gow ◽  
J. Witt ◽  
R. Zemlak
Keyword(s):  
Microsatellite Dna ◽  
Geographic Distance ◽  
Genetic Distances ◽  
Population Subdivision ◽  
Effective Management ◽  
Branch Points ◽  
Stream Networks ◽  
Dna Variation ◽  
Reservoir Watershed ◽  
Northwestern North America

We studied microsatellite DNA variation in 15 populations of northwestern North American pygmy whitefish ( Prosopium coulterii (Eigenmann and Eigenmann, 1892)), an enigmatic freshwater fish thought to be highly fragmented by residency in deep, cold postglacial lakes. Population subdivision (θ) across 10 loci was 0.12 (P < 0.001) across samples, but one western Alaskan population was more divergent than all others (θ = 0.31–0.41, P < 0.001). Within the Williston Reservoir watershed (WRW), θ averaged 0.08 (P < 0.001) and was positively associated with both the geographic distance between localities (r2 = 0.36, P < 0.001) and the number of branch points interconnecting them (r2 = 0.33, P < 0.001). Differentiation among populations was modeled as the sum of the genetic distances for the stream sections interconnecting them (r2 = 0.74). Differences among subwatersheds with the WRW accounted for 5.1% of the total variation in allele frequencies (P < 0.001). Assignment tests suggested limited movement among lakes, with most inferred dispersal between adjacent watersheds. Coalescent analysis strongly supported a gene flow–drift equilibrium model of population structure over a drift-only model. Effective management of diversity in pygmy whitefish requires the maintenance of stream networks that interconnect lakes within a watershed.

Conservation Genetics of Corroboree Frogs, Pseudophryne-Corroboree Moore (Anura, Myobatrachidae) - Population Subdivision and Genetic-Divergence

1991 ◽  
Vol 39 (3) ◽  
pp. 285 ◽  
Author(s):  
WS Osborne ◽  
JA Norman
Keyword(s):  
Genetic Divergence ◽  
Conservation Management ◽  
Geographic Distance ◽  
Genetic Distances ◽  
Population Subdivision ◽  
Southern Form ◽  
Eastern Australia ◽  
Geographic Populations ◽  
Taxonomic Implications ◽  
Growth Abnormalities

Reproductive compatibility and population genetic structure were examined in the corroboree frog, Pseudophryne corroboree, a species restricted to montane and subalpine environments in south-eastern Australia. The species comprises three geographic populations, represented by two morphological forms. Hybridisation experiments showed that the allopatric populations are interfertile, although crosses between the Snowy Mountains population (southern form) and each of the two northern populations (northern form) resulted in a significantly higher number of tadpoles with growth abnormalities. An electrophoretic examination of metamorphlings indicated that there was considerable genetic divergence between the two forms, with several loci approaching fixation of alternate alleles. The Snowy Mountains population also had substantially reduced levels of genetic variation compared to the two northern populations. Although genetic distances generally correlate with geographic distance, the genetic differences between the northern and southern populations form a pronounced step, not explicable by geographic distance alone. These findings have taxonomic implications which should be taken into account when considering the conservation management of this uncommon species.

Detection of genetic diversity in rough fescue (Festuca campestris Rydb) populations of southern Alberta and British Columbia, Canada, using RAPD markers

2008 ◽  
Vol 88 (2) ◽  
pp. 307-312
Author(s):  
Zhao Mengli ◽  
Han Bing ◽  
Walter D Willms
Keyword(s):  
Genetic Diversity ◽  
British Columbia ◽  
Genetic Distance ◽  
Random Amplified Polymorphic Dna ◽  
Geographic Distance ◽  
Genetic Distances ◽  
Gene Frequencies ◽  
Southern Alberta ◽  
Potential Adaptation ◽  
Rough Fescue

Mountain rough fescue (Festuca campestris Rydb.) is a tufted native grass in southern Alberta and British Columbia, Canada, and has attracted interest for use in reclamation. However, its seed is often available from only a few localized sources and may not be adapted for areas removed from the collection site. We conducted a study to determine the genetic variability among rough fescue populations to assess its potential adaptation. Thirty plants were collected from each of six populations and analyzed using Random Amplified Polymorphic DNA (RAPD). One population (Kamloops, BC) was separated by several mountain ranges from the five easterly Alberta populations.The Kamloops population was also separated from the Alberta populations by genetic distance in two clusters. Of the total genetic variation present in the data, 21% was found among populations while the remaining (79%) was found within populations. Nei’s genetic distances among populations were related to their geographical distances. Genetic differences among populations appeared to be caused primarily by differences in gene frequencies rather than rare genes. Also, genetic diversity appeared to increase from west to east suggesting that the more easterly populations had greater adaptation potential. We speculate that the more easterly populations are less likely to share genes since the prevailing winds are from the west. Germplasm from the more easterly populations may be used with suitable precautions within Alberta and possibly around Kamloops. Key words: Genetic distance, geographic distance, reclamation, potential adaptation

scholarly journals DNA Variation in a Diversity Panel of Tomato Genetic Resources

2021 ◽  
pp. 1-7
Author(s):  
Joanne A. Labate
Keyword(s):  
Single Nucleotide Polymorphisms ◽  
Crop Improvement ◽  
Genotyping By Sequencing ◽  
Genetic Distances ◽  
Nucleotide Polymorphisms ◽  
Fresh Market ◽  
Single Nucleotide ◽  
Dna Variation ◽  
Diversity Panel ◽  
Home Gardening

A diversity panel of 190 National Plant Germplasm System (NPGS) tomato (Solanum lycopersicum) accessions was genotyped using genotyping by sequencing. These originated from 31 countries and included fresh market, ornamental, processing, breeders’ lines, landraces, and home gardening types, as well as six different accessions of the economically valuable cultivar San Marzano. Most of the 34,531 discovered single nucleotide polymorphisms were rare and therefore excluded from downstream analyses. A total of 3713 high-quality, mapped single nucleotide polymorphisms that were present in at least two accessions were used to estimate genetic distances and population structure. Results showed that these phenotypically and geographically diverse NPGS tomato accessions were closely related to each other. However, a subset of divergent genotypes was identified that included landraces from primary centers of diversity (South America), secondary centers of diversity (Italy, Taiwan, and France), and genotypes that originated from wild species through 20th century breeding for disease resistance (e.g., ‘VFNT Cherry’). Extreme variant accessions produce cultivated fruit traits in a background that contains many wild or primitive genes. These accessions are promising sources of novel genes for continued crop improvement.

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.

Connectivity of prairie dog colonies in an altered landscape: inferences from analysis of microsatellite DNA variation

2011 ◽  
Vol 13 (2) ◽  
pp. 407-418 ◽  
Author(s):  
Loren C. Sackett ◽  
Todd B. Cross ◽  
Ryan T. Jones ◽  
Whitney C. Johnson ◽  
Kimberly Ballare ◽  
...  
Keyword(s):  
Microsatellite Dna ◽  
Prairie Dog ◽  
Dna Variation

Microsatellite analysis of genetic variability in Waler horses from Australia

2013 ◽  
Vol 61 (5) ◽  
pp. 357 ◽  
Author(s):  
Anas M. Khanshour ◽  
Rytis Juras ◽  
E. Gus Cothran
Keyword(s):  
Genetic Diversity ◽  
Genetic Variability ◽  
Bayesian Method ◽  
Genetic Relationships ◽  
Similarity Measures ◽  
Genetic Distances ◽  
Microsatellite Analysis ◽  
Population Subdivision ◽  
Factorial Correspondence Analysis ◽  
Horse Breed

The Waler horse breed is an integral part of Australian history. The purposes of this study were to analyse the genetic variability in Waler horses from Australia and to investigate genetic relationships with other horse breeds. We examined the genetic diversity of 70 Waler horses sampled from seven breeding stations in Australia. Also we analysed the relationships of these horses with 11 other horse breeds. Analysis of the genetic structure was carried out using 15 microsatellite loci, genetic distances, AMOVA, factorial correspondence analysis and a Bayesian method. We found that the genetic diversity in the Waler was greater than the domestic horse mean and exceeded that of all endangered horse breeds. Our findings also revealed moderate population subdivision rather than inbreeding. All genetic similarity measures indicated that the Thoroughbred might be a key ancestor to the Waler. This study indicates that there is no immediate concern for loss of variation in Waler horses. Also, there clearly has been a strong input from the Thoroughbred into the Waler horse breed. However, the genetic evidence suggests that this input was not just direct but also came through other types of horses with a Thoroughbred cross background.

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