Genetic Differentiation among Populations of the Northern Redbelly Dace (Phoxinus eos) in Ontario

1994 ◽  
Vol 51 (6) ◽  
pp. 1218-1228 ◽  
Author(s):  
C. Anna Toline ◽  
Allan J. Baker
Keyword(s):  
Gene Flow ◽  
Genetic Differentiation ◽  
Fish Species ◽  
Protein Electrophoresis ◽  
The Other ◽  
Population Divergence ◽  
Average Heterozygosity ◽  
Weinberg Equilibrium ◽  
Hardy Weinberg Equilibrium ◽  
Population Substructuring

Eighteen populations of northern redbelly dace (Phoxinus eos) from three regions in Ontario were examined genetically using protein electrophoresis. Differentiation among regions was greater (FST = 0.100) than within them (FST = 0.045–0.064), suggesting that levels of gene flow are high enough to prevent differentiation through drift only within regions. Levels of heterozygosity, percent polymorphic loci, and number of alleles per locus are high relative to other fish species, which suggests that populations of dace in this study have not been subject to severe bottlenecks. Thus, population divergence has apparently occurred gradually over the last 10 000 yr. Average heterozygosity was not correlated with pond area. Thus, populations in Algonquin Park are not more prone to the effects of drift than those in the other two regions. Populations from the Sudbury region were genetically differentiated from those in Algonquin Park and from near Kingston, a result consistent with the historical biogeography of Ontario. Despite relatively high levels of heterozygosity, observed levels in this study deviated significantly from those expected from Hardy–Weinberg equilibrium. The breeding biology of P. eos and other fish suggests that our results may be explained by the presence of population substructuring in the localities sampled.

The Use of Protein Electrophoresis for Determining Species Boundaries in Amphipods

Crustaceana ◽  
1993 ◽  
Vol 65 (2) ◽  
pp. 265-277 ◽  
Author(s):  
Barbara A. Stewart
Keyword(s):  
Gene Flow ◽  
Genetic Differentiation ◽  
Morphological Variation ◽  
Protein Electrophoresis ◽  
Species Boundaries ◽  
Allopatric Populations ◽  
A Value ◽  
Electrophoretic Data

AbstractThe use of protein electrophoretic data for determining species boundaries in amphipods is addressed. Analysis of published literature on genetic differentiation in amphipods showed that pairs of allopatric populations which have genetic identities (I) above a value of 0.85 probably represent intraspecific populations, whereas pairs of populations which have genetic identities below about 0.45 probably represent different species. It was recommended that if I values fall between 0.45 and 0.85, additional factors such as evidence of a lack of gene flow between the populations, and concordant morphological variation should be considered.

Enzyme polymorphism in Schistosoma mattheei from cattle in the Eastern Transvaal Lowveld

1989 ◽  
Vol 63 (3) ◽  
pp. 191-196 ◽  
Author(s):  
F. J. Kruger
Keyword(s):  
Adult Worm ◽  
Malate Dehydrogenase ◽  
Enzyme Polymorphism ◽  
The Other ◽  
Enzyme Electrophoresis ◽  
Weinberg Equilibrium ◽  
Hardy Weinberg Equilibrium ◽  
Glucose 6 Phosphate Dehydrogenase

ABSTRACTEnzyme electrophoresis was conducted on 10 Schistosoma mattheei adult worm samples, comprising 270 individuals, collected from cattle in the Eastern Transvaal Lowveld. Glucose-6-phosphate dehydrogenase (G6PDH) was studied in all the samples and phosphoglucomutase (PGM) and malate dehydrogenase (MDH) in five populations each. Only one population was polymorphic for G6PDH. In this population, in addition to the allele found in all the other samples, a second allele occurred with a similar Rf value to S. haematobium. The two alleles were in Hardy-Weinberg equilibrium. MDH-1 exhibited two alleles. However, these alleles were not in equilibrium. In certain populations, heterozygotes occurred together with homozygotes of one of the alleles only. PGM was monomorphic in all the populations studied.

Genetic variation within and relationships among five subpopulations of Slovak Thoroughbred

2004 ◽  
Vol 52 (3) ◽  
pp. 259-265
Author(s):  
Daniela Šátková-Jakabová ◽  
J. Trandžík ◽  
Ľudmila Hudecová-Kvasňáková ◽  
Erika Hegedüšová-Zetochová ◽  
A. Bugarský ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Genetic Differentiation ◽  
International Society ◽  
Microsatellite Loci ◽  
Genetic Relationships ◽  
Allele Frequencies ◽  
Weinberg Equilibrium ◽  
Hardy Weinberg Equilibrium

Genetic variation at six microsatellite loci was analysed for five Thoroughbred subpopulations to determine the magnitude of genetic differentiation and the genetic relationships among the subpopulations. Significant deviations from Hardy-Weinberg equilibrium were shown for a number of locus-population combinations, with all subpopulations. The genetic diversities and relationships of five Thoroughbred subpopulations were evaluated using six microsatellites recommended by the International Society of Animal Genetics (ISAG). The allele frequencies, the effective numbers of alleles, and the observed and expected heterozygosities were calculated. POPGENE v. 1.31 (Yeh et al., 1997) was used to test for deviations from the Hardy-Weinberg (H-W) equilibrium and to assign FIS estimates (Weir, 1990). The utility of microsatellites for evaluating genetic diversity of horses is discussed.

Lakes Michigan and Huron limit gene flow between the subspecies of the butterfly Limenitis arthemis

1988 ◽  
Vol 66 (8) ◽  
pp. 1790-1795 ◽  
Author(s):  
G. P. Waldbauer ◽  
J. G. Sternburg ◽  
A. W. Ghent
Keyword(s):  
Gene Flow ◽  
Upper Peninsula ◽  
Weinberg Equilibrium ◽  
Hardy Weinberg Equilibrium ◽  
Lower Peninsula ◽  
Straits Of Mackinac

Near the Straits of Mackinac, the Limenitis arthemis population on Michigan's Upper Peninsula consists mostly of the disruptively banded L. a. arthemis, while the population on its Lower Peninsula consists mostly of the unbanded, mimetic L. a. astyanax and arthemis–astyanax intergrades. Except at the straits, the Upper and Lower peninsulas are broadly separated by lakes Michigan and Huron. On the Lower Peninsula, arthemis-like forms are most common on the shore close to the Upper Peninsula but are much less frequent only 20 km south, probably because of the northward flow of astyanax genes. Neither population is in Hardy–Weinberg equilibrium because of a deficiency of "hétérozygotes," possibly because of cross-lake emigration at the straits.

scholarly journals Reported CCR5-∆32 deviation from Hardy-Weinberg equilibrium is explained by poor genotyping of rs62625034

2019 ◽  
Author(s):  
Yosuke Tanigawa ◽  
Manuel A. Rivas
Keyword(s):  
Hiv Infection ◽  
Chemokine Receptor ◽  
Survival Probability ◽  
Gene Editing ◽  
Nature Medicine ◽  
The Other ◽  
Ccr5 Chemokine Receptor ◽  
Weinberg Equilibrium ◽  
Ethical Concerns ◽  
Hardy Weinberg Equilibrium

AbstractIn the fall of 2018, news broke about a researcher from China who had used CRISPR gene editing to cause human babies to have a deletion in the CCR5 chemokine receptor, making them resistant to HIV infection. One of the numerous ethical concerns about this study is that the deletion may have other effects. Subsequently, Nature Medicine published a Brief Communications from Wei and Nielsen concluding that homozygotes for the CCR5-∆32 deletion have a survival probability to age 76 of 83.5% compared to 86.5% and 86.4% for the heterozygotes and the other homozygote, respectively, and that observed departures from Hardy Weinberg proportions also support selection operating on this allele1. In the study, Wei and Nielsen used a proxy variant, rs62625034 in their analysis. Here, we report that the reported CCR5-∆32 deviation from Hardy-Weinberg equilibrium (HWE) inferred by Wei and Nielsen can be explained by poor genotyping of rs62625034, the variant used for their analysis.

Allozyme variation and genetic divergence in the sand goby, Pomatoschistus minutus (Teleostei: Gobiidae)

2003 ◽  
Vol 83 (5) ◽  
pp. 1143-1149 ◽  
Author(s):  
S. Stefanni ◽  
E.S. Gysels ◽  
F.A.M. Volckaert ◽  
P.J. Miller
Keyword(s):  
Gene Flow ◽  
Genetic Differentiation ◽  
Adriatic Sea ◽  
Allozyme Variation ◽  
Western Mediterranean ◽  
The Other ◽  
Sand Goby ◽  
Sea Levels ◽  
Pomatoschistus Minutus ◽  
The North

Samples of the widely distributed sand goby Pomatoschistus minutus have been investigated genetically from ten localities in the north-eastern Atlantic, North Sea, western Mediterranean and Adriatic Sea. Levels of genetic diversity and differentiation were assessed with starch (SGE) and cellulose acetate (CAGE) gel electrophoresis for 13 enzyme systems. Genetic differentiation between spatial samples points to a reduction or even absence of gene flow between the Adriatic and the other samples, including the western Mediterranean Sea (pair-wise FST=0.37 and 0.32 for SGE and CAGE respectively). The sample from the Adriatic Sea was clearly differentiated from the other samples at the lactate dehydrogenase loci LDH-A* (SGE and CAGE) and LDH-C* (CAGE). Values for genetic differentiation between Venetian and other sand gobies were of the same order of magnitude as between P. minutus and its closest relative P. lozanoi, suggesting allopatric speciation in the lagoon of Venice. At locations outside the Adriatic Sea, the sand goby has the typical features of a marine fish with a high level of gene flow and a low degree of genetic differentiation.

scholarly journals Genetic diversity of Matrinxã breeding stocks: implications for management and conservation

2021 ◽  
Vol 42 (2) ◽  
pp. 757-768
Author(s):  
Angela Maria Urrea Rojas ◽  
◽  
Felipe Pinheiro de Souza ◽  
Ed Christian Suzuki de Lima ◽  
Claudete de Fátima Ruas ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variability ◽  
Genetic Differentiation ◽  
Genetic Drift ◽  
Polymorphic Information Content ◽  
Common Origin ◽  
Null Alleles ◽  
Mato Grosso ◽  
Weinberg Equilibrium ◽  
Hardy Weinberg Equilibrium

The formation of fish breeding stocks for fish farming or conservation programs is commonly carried out from the capture of fish in natural environments. Information on the geographic and genetic origin of these stocks is important to guide actions that allow correct management in captivity and, when lost, harm production and genetic conservation. In this sense, the objective of this study was to evaluate the genetic diversity and origin of two breeding stocks of matrinxã, Brycon amazonicus (INPA, Amazonas - INPA and Nova Motum, Mato Grosso - NM). A total of 68 caudal fin samples were collected, including 33 INPA samples and 35 NM samples. Twenty pairs of microsatellite primers were tested, but only seven primers showed satisfactory amplification, amplifying 41 alleles ranging from 187-318 bp. The polymorphic information content ranged from 0.135 (Borg25) to 0.782 (Bh6). Exclusive alleles were observed for both populations (INPA: 04 and NM: 18). Allelic richness results revealed that there was increased loss of genetic variation in NM, indicating a lower evolutionary potential of this stock. The average values of the observed heterozygosity corroborated this statement; however, there were high values for INPA (0.545) and NM (0.475), signifying an adequate genetic variability. An imbalance was found in the Hardy-Weinberg equilibrium at the Borg59 locus in INPA (P < 0.05), possibly due to the effect of null alleles, but was attributed to a founder effect. For NM, an imbalance in the Hardy-Weinberg equilibrium was observed at loci BoM13 and Bh6, which together with the results of the mean inbreeding coefficient values demonstrated the presence of genetic drift. The analysis of molecular variance showed greater variation within populations than between them, and was confirmed by the genetic differentiation value (0.086 - moderate genetic differentiation) and by the distance and genetic identity values (0.273 and 0.761, respectively). Bayesian analysis designated a value of K = 2, with the presence of structuring for NM and INPA; however, with correlated allelic frequencies, confirming a common origin. This origin was corroborated by the presence of gene flow through the number of migrants (5.691). Based on these results, there was a moderate genetic variability for INPA and NM and their common origin was confirmed. Recommendations are also included to minimize the probability of inbreeding processes or genetic drift in the studied stocks.

scholarly journals Genetic diversity detection of the domestic horse (Equus caballus) by genes associated with coat color

2015 ◽  
pp. 4779-4789
Author(s):  
Luz Correa A ◽  
Cindy Reyes E ◽  
Enrique Pardo P ◽  
Teodora Cavadia M
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Genetic Distance ◽  
Coat Color ◽  
Equus Caballus ◽  
Phenotypic Characterization ◽  
Domestic Horse ◽  
Global Level ◽  
Weinberg Equilibrium ◽  
Hardy Weinberg Equilibrium

ABSTRACT Objective. To assess the population structure and genetic diversity in populations of domestic horse (Equus caballus) in the municipality Cienaga de Oro-Córdoba (Colombia). Materials and methods. Random sampling were conducted between August and October 2013, in adult animals on farms seven districts, which was carried out phenotypic characterization of each animal, based on autosomal markers encoding morphological Extension (E) , Agouti (A), Cream (C), White (W), Gray (G), Tobiano (TO), Overo (O) and Roan (RN). Population genetic parameters: allele frequency, genetic diversity, gene flow, Hardy-Weinberg equilibrium and genetic distance were calculated through the program POPGENE 1.31; the genetic structure was assessed using the program FSTAT v. 2.9.3.2. Results. 341 individuals were analyzed in the seven populations studied, where the Extension gene Was the MOST faq frequently as the Overo and Tobiano genes showed the lowest values. Insignificant values of genetic variability and population recorded a global level, likewise, low genetic differentiation among populations, accompanied by a high gene flow was obtained; an excess of heterozygotes at population and global level was observed; to this is added the presence of Hardy-Weinberg equilibrium in all populations relative to the markers studied and low genetic distance values were reported. Conclusions. The populations are highly genetically related, a situation that may result from the existing geographical proximity between them, favoring genetic exchange and the establishment of a metapopulation.

scholarly journals Genetic differentiation and estimated levels of gene flow in members of the Gammarus pulex-group (Crustacea, Amphipoda) in western Europe

1990 ◽  
Vol 60 (1) ◽  
pp. 3-29 ◽  
Author(s):  
Maarten Scheepmaker
Keyword(s):  
Gene Flow ◽  
Genetic Differentiation ◽  
Sibling Species ◽  
Gene Frequency ◽  
Western Europe ◽  
Distinct Species ◽  
Genetic Distances ◽  
The Other ◽  
Frequency Data ◽  
Population Sizes

Genetic differentiation of morphologically variable members of the G. pulex-group in northwestern Europe was investigated by electrophoresisat 20 enzyme loci. Five recently described related forms were examined with reference to the “classical” species G. pulex, G. wautieri and G. fossarum. G. pulex and G. wautieri were shown to be genetically homogeneous and clearly distinct species. In the other species, morphologicallysimilar forms were shown to be genetically distant, and inter-areal intraspecific genetic differentiation may warrant recognition of subspecies or sibling species. In some cases, levels of reproductive isolation of the forms involved could be assessed by cross-breeding experiments. To estimate dispersal capabilities, gene flow levels were indirectly estimated from gene frequency data. Gene flow levels are generally low and fluctuating population sizes may enhance the occurrence of stochastic processes. Dendrograms derived from genetic distances were compared with zoogeographical and paleoclimatological evidence. The distribution areas of the species involved correspond to patterns predicted by these data.

Genetic differentiation of Sorbus torminalis in Eastern Europe as determined by microsatellite markers

Biologia ◽  
2010 ◽  
Vol 65 (5) ◽  
Author(s):  
Veronika Kučerová ◽  
Martin Honec ◽  
Ladislav Paule ◽  
Petar Zhelev ◽  
Dušan Gömöry
Keyword(s):  
Genetic Variation ◽  
Gene Flow ◽  
Genetic Differentiation ◽  
Bayesian Methods ◽  
Isolation By Distance ◽  
General Pattern ◽  
The Other ◽  
Hand Model ◽  
Sorbus Torminalis ◽  
Nuclear Microsatellite

AbstractThe genetic variation in fourteen Sorbus torminalis (L.) Crantz. populations distributed over the eastern and south-eastern part of its range was studied using seven nuclear microsatellite loci. The differentiation level was relatively high (F ST = 0.228), as expected for a species with a fragmented range. The distance-based approach to the analysis of differentiation patterns (neighbour-joining tree based on pairwise coefficients of differentiation) did not reveal a clear geographical structure. On the other hand, model-based Bayesian methods (BAPS and STRUCTURE) gave geographically continuous clusters of populations. The occurrence of populations deviating strongly from the general pattern is attributed to founder effect. In spite of a generally high differentiation, a significant isolation-by-distance pattern was found, which might be a consequence of postglacial migration and gene flow among descendants of different refugia.

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