scholarly journals Population Genetic Assessment of Anadromous and Resident Striped Bass (Morone saxatilis) in the Roanoke River System, Eastern United States

Fishes ◽  
2020 ◽  
Vol 5 (3) ◽  
pp. 24
Author(s):  
Sheila C. Harris ◽  
W. Robert Cope ◽  
Isaac Wirgin ◽  
Eric M. Hallerman
Keyword(s):  
South Carolina ◽  
Genetic Variation ◽  
Striped Bass ◽  
Population Genetic ◽  
System Analysis ◽  
Hudson River ◽  
Mountain Lake ◽  
River Drainage ◽  
Population Genetic Differentiation ◽  
Roanoke River

Striped bass is the subject of important commercial and sport fisheries in North America. The Roanoke River drainage—especially Smith Mountain Lake, Leesville Lake, and Kerr Reservoir—has popular recreational striped bass fisheries. After construction of five hydroelectric dams, populations became landlocked, declined, and have been supplemented by stocking. A key basis for responsibly augmenting populations is to characterize genetic variation and incorporate the findings into responsible hatchery and stocking practices. Genetic variation at 12 microsatellite DNA loci was evaluated among 837 striped bass representing 16 collections across the native range; populations from rivers in South Carolina, North Carolina, Chesapeake Bay, and Hudson River were screened to provide context for assessing genetic structure within the Roanoke system. Analysis of population genetic differentiation showed landlocked Roanoke River striped bass to be distinctive. Subject to genetic isolation, high M ratios, and relatively low Ne estimates suggest loss of genetic variation, and relatedness analysis showed heightened frequencies of related individuals. These insights into population genetics, demographics, and existing guidelines for broodstock acquisition and mating designs can inform genetically cognizant hatchery management and stocking for striped bass in the Roanoke River drainage. In particular, we recommend the use of larger numbers of breeders and factorial mating designs to increase the genetic diversity of propagated striped bass stocked within the Roanoke River drainage.

Genetic Variation and Management of Striped Bass Populations in the Coastal Rivers of South Carolina

2004 ◽  
Vol 24 (4) ◽  
pp. 1322-1329 ◽  
Author(s):  
James S. Bulak ◽  
Christopher S. Thomason ◽  
Kaiping Han ◽  
Bert Ely
Keyword(s):  
South Carolina ◽  
Genetic Variation ◽  
Striped Bass ◽  
Coastal Rivers

scholarly journals Do Mediterranean crickets Gryllus bimaculatus De Geer (Orthoptera: Gryllidae) come from the Mediterranean? Largescale phylogeography and regional gene flow

2009 ◽  
Vol 100 (1) ◽  
pp. 49-58 ◽  
Author(s):  
M. Ferreira ◽  
J.W.H. Ferguson
Keyword(s):  
Genetic Variation ◽  
Gene Flow ◽  
Genetic Differentiation ◽  
South African ◽  
Population Genetic ◽  
Genetic Differences ◽  
Field Cricket ◽  
Gryllus Bimaculatus ◽  
Population Genetic Differentiation ◽  
The Mediterranean

AbstractWe investigate the degree of between-population genetic differentiation in the Mediterranean field cricket Gryllus bimaculatus, as well as the possible causes of such differentiation. Using cytochrome b mtDNA sequences, we estimate genetic variation in G. bimaculatus from seven South African and two Mediterranean populations. Within-population genetic variation in Europe (two haplotypes, one unique to a single individual) suggest low effective population size and strong bottlenecks with associated founder effects, probably due to cold winter environments in Europe that limit reproduction to a short part of the summer. The likely cause for this is the daily maxima in winter temperatures that fall below the critical level of 16°C (enabling normal calling and courtship behaviour) in Mediterranean Europe, whereas the equivalent temperatures in southern Africa are above this limit and enable reproduction over a large part of the year. European genetic variants were either shared with Africa or closely related to African haplotypes. For survival, European populations are probably dependent on immigration from other areas, including Africa. South African populations have low but measurable gene flow with Europe and show significant between-population genetic differentiation (30 haplotypes). Isolation-by-distance is not sufficient to explain the degree of between-population genetic differences observed, and a large degree of dispersal is also required in order to account for the observed patterns. Differences in morphology and calling behaviour among these populations are underlied by these genetic differences.

scholarly journals Long-Term Experimental Evolution in Escherichia coli. VI. Environmental Constraints on Adaptation and Divergence

Genetics ◽  
1997 ◽  
Vol 146 (2) ◽  
pp. 471-479 ◽  
Author(s):  
Michael Travisano
Keyword(s):  
Escherichia Coli ◽  
Genetic Variation ◽  
Experimental Evolution ◽  
Population Genetic ◽  
Environmental Constraints ◽  
Asymmetric Pattern ◽  
Nutrient Environment ◽  
Mean Fitness ◽  
Population Genetic Variation

The effect of environment on adaptation and divergence was examined in two sets of populations of Escherichia coli selected for 1000 generations in either maltose- or glucose-limited media. Twelve replicate populations selected in maltose-limited medium improved in fitness in the selected environment, by an average of 22.5%. Statistically significant among-population genetic variation for fitness was observed during the course of the propagation, but this variation was small relative to the fitness improvement. Mean fitness in a novel nutrient environment, glucose-limited medium, improved to the same extent as in the selected environment, with no statistically significant among-population genetic variation. In contrast, 12 replicate populations previously selected for 1000 generations in glucose-limited medium showed no improvement, as a group, in fitness in maltose-limited medium and substantial genetic variation. This asymmetric pattern of correlated responses suggests that small changes in the environment can have profound effects on adaptation and divergence.

Significant genetic differences among Heterodera schachtii populations within and among sugar beet production areas

Nematology ◽  
2020 ◽  
Vol 22 (2) ◽  
pp. 165-177 ◽  
Author(s):  
Rasha Haj Nuaima ◽  
Johannes Roeb ◽  
Johannes Hallmann ◽  
Matthias Daub ◽  
Holger Heuer
Keyword(s):  
Genetic Variation ◽  
Genetic Structure ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
Spatial Scales ◽  
Geographic Distance ◽  
Heterodera Schachtii ◽  
Parasitic Nematodes ◽  
Neutral Genetic Variation ◽  
Production Areas

Summary Characterising the non-neutral genetic variation within and among populations of plant-parasitic nematodes is essential to determine factors shaping the population genetic structure. This study describes the genetic variation of the parasitism gene vap1 within and among geographic populations of the beet cyst nematode Heterodera schachtii. Forty populations of H. schachtii were sampled at four spatial scales: 695 km, 49 km, 3.1 km and 0.24 km. DGGE fingerprinting showed significant differences in vap1 patterns among populations. High similarity of vap1 patterns appeared between geographically close populations, and occasionally among distant populations. Analysis of spatially sampled populations within fields revealed an effect of tillage direction on the vap1 similarity for two of four studied fields. Overall, geographic distance and similarity of vap1 patterns of H. schachtii populations were negatively correlated. In conclusion, the population genetic structure was shaped by the interplay between the genetic adaptation and the passive transport of this nematode.

Dispersal of Young-of-the-Year Hatchery Striped Bass in the Hudson River

1991 ◽  
Vol 11 (3) ◽  
pp. 381-392 ◽  
Author(s):  
Alan W. Wells ◽  
Donna M. Randall ◽  
Dennis J. Dunning ◽  
John R. Young
Keyword(s):  
Striped Bass ◽  
Hudson River ◽  
Young Of The Year

scholarly journals The coalescent process in models with selection, recombination and geographic subdivision

1991 ◽  
Vol 57 (1) ◽  
pp. 83-91 ◽  
Author(s):  
Norman Kaplan ◽  
Richard R. Hudson ◽  
Masaru Iizuka
Keyword(s):  
Genetic Variation ◽  
Population Genetic ◽  
Genetic Model ◽  
Sequence Data ◽  
Balancing Selection ◽  
Similar Model ◽  
Proposed Model ◽  
Coalescent Approach ◽  
Neutral Mutations ◽  
Better Than

SummaryA population genetic model with a single locus at which balancing selection acts and many linked loci at which neutral mutations can occur is analysed using the coalescent approach. The model incorporates geographic subdivision with migration, as well as mutation, recombination, and genetic drift of neutral variation. It is found that geographic subdivision can affect genetic variation even with high rates of migration, providing that selection is strong enough to maintain different allele frequencies at the selected locus. Published sequence data from the alcohol dehydrogenase locus of Drosophila melanogaster are found to fit the proposed model slightly better than a similar model without subdivision.

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