Genetic differentiation among populations of Weidemeyer's admiral butterfly

1989 ◽  
Vol 67 (9) ◽  
pp. 2294-2300 ◽  
Author(s):  
Risa H. Rosenberg
Keyword(s):  
Genetic Differentiation ◽  
Social Systems ◽  
Starch Gel Electrophoresis ◽  
Effective Population ◽  
Isolated Populations ◽  
Genetic Structure Of Populations ◽  
Two Factors ◽  
Population Sizes ◽  
Starch Gel ◽  
Allozyme Loci

I assessed the genetic differentiation of populations of Weidemeyer's admiral butterfly (Limenitis weidemeyerii) in central and eastern Colorado by using starch-gel electrophoresis. Wright's F-statistics indicated that there was significant differentiation, both within and between years, among the same populations analyzed for 2 successive years, and among populations, even those in close geographic proximity. Consequently, no correlation was found between the genetic identities and geographic distances between pairs of populations. To explain the genetic structure of populations, I estimated patterns of movement and effective sizes of populations. I assessed movement of individuals by using mark–recapture techniques, which indicated that travel over the season for both sexes was negligible (range 0–2850 m, mean 166 m). I estimated effective population sizes by using Pollak's methods, and as would be expected for populations with territorial social systems, effective sizes were small (ranging from 17 to 131, mean 61). These two factors, small and isolated populations, suggest that a significant portion of the genetic differentiation observed at allozyme loci among populations of Weidemeyer's admiral butterfly in Colorado is mediated by random genetic drift.

scholarly journals Sporadic Genetic Connectivity among Small Insular Populations of the Rare Geoendemic Plant Caulanthus amplexicaulis var. barbarae (Santa Barbara Jewelflower)

2019 ◽  
Vol 110 (5) ◽  
pp. 587-600
Author(s):  
A Millie Burrell ◽  
Jeffrey H R Goddard ◽  
Paul J Greer ◽  
Ryan J Williams ◽  
Alan E Pepper
Keyword(s):  
Gene Flow ◽  
Genetic Connectivity ◽  
Effective Population ◽  
Evolutionary Potential ◽  
Isolated Populations ◽  
Long Distance ◽  
Population Sizes ◽  
History Of ◽  
Small Set ◽  
Nuclear Microsatellite

Abstract Globally, a small number of plants have adapted to terrestrial outcroppings of serpentine geology, which are characterized by soils with low levels of essential mineral nutrients (N, P, K, Ca, Mo) and toxic levels of heavy metals (Ni, Cr, Co). Paradoxically, many of these plants are restricted to this harsh environment. Caulanthus ampexlicaulis var. barbarae (Brassicaceae) is a rare annual plant that is strictly endemic to a small set of isolated serpentine outcrops in the coastal mountains of central California. The goals of the work presented here were to 1) determine the patterns of genetic connectivity among all known populations of C. ampexlicaulis var. barbarae, and 2) estimate contemporary effective population sizes (Ne), to inform ongoing genomic analyses of the evolutionary history of this taxon, and to provide a foundation upon which to model its future evolutionary potential and long-term viability in a changing environment. Eleven populations of this taxon were sampled, and population-genetic parameters were estimated using 11 nuclear microsatellite markers. Contemporary effective population sizes were estimated using multiple methods and found to be strikingly small (typically Ne < 10). Further, our data showed that a substantial component of genetic connectivity of this taxon is not at equilibrium, and instead showed sporadic gene flow. Several lines of evidence indicate that gene flow between isolated populations is maintained through long-distance seed dispersal (e.g., >1 km), possibly via zoochory.

scholarly journals Quantifying the individual impact of artificial barriers in freshwaters: A standardized and absolute genetic index of fragmentation

2019 ◽  
Author(s):  
Jérôme G. Prunier ◽  
Camille Poesy ◽  
Vincent Dubut ◽  
Charlotte Veyssière ◽  
Géraldine Loot ◽  
...  
Keyword(s):  
Genetic Differentiation ◽  
Molecular Data ◽  
Freshwater Biodiversity ◽  
Effective Population ◽  
Barrier Effects ◽  
Population Sizes ◽  
The Individual ◽  
Independent Assessment ◽  
Objective Tool ◽  
Genetic Index

AbstractFragmentation by artificial barriers is an important threat to freshwater biodiversity. Mitigating the negative aftermaths of fragmentation is of crucial importance, and it is now essential for environmental managers to benefit from a precise estimate of the individual impact of weirs and dams on river connectivity. Although the indirect monitoring of fragmentation using molecular data constitutes a promising approach, it is plagued with several constraints preventing a standardized and individual quantification of barrier effects. Indeed, observed levels of genetic differentiation depend on both the age of the obstacle and the effective size of the populations it separates, making difficult comparisons of the actual barrier effect of different obstacles. Here, we developed a standardized genetic index of fragmentation (FINDEX), allowing an absolute and independent assessment of the individual effects of obstacles on connectivity. The FINDEX is the standardized ratio (expressed as a percentage) between the observed genetic differentiation between pairs of populations located on either side of an obstacle and the genetic differentiation expected if this obstacle completely prevented gene flow. The expected genetic differentiation is calculated from simulations taking into account two nuisance parameters: the number of generations since barrier creation (the age of the obstacle) and the expected heterozygosity of the targeted populations, a proxy for effective population sizes. Using both simulated and published empirical datasets, we explored and discussed the validity and the limits of the FINDEX. We demonstrated that it allows quantifying genetic effects of fragmentation only from a few generations after barrier creation and provides valid comparisons among populations (or species) of different effective populations sizes and obstacles of different ages. The computation of the FINDEX requires a minimum amount of fieldwork and genotypic data, and solves some of the difficulties inherent to the study of artificial fragmentation in rivers and potentially in other ecosystems. This makes the FINDEX a promising and objective tool for managers aiming at at planning restoration programs and at evaluating the efficiency of these programs.

scholarly journals ALLOZYME INHERITANCE AND DIVERSITY IN SOUR CHERRY

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1081a-1081
Author(s):  
James Beaver ◽  
Amy Iezzoni
Keyword(s):  
Germplasm Collection ◽  
Sour Cherry ◽  
Starch Gel Electrophoresis ◽  
Shikimate Dehydrogenase ◽  
Heterozygous Condition ◽  
Segregation Data ◽  
Disomic Inheritance ◽  
Leucine Amino Peptidase ◽  
Starch Gel ◽  
Allozyme Loci

Starch gel electrophoresis was employed to study inheritance and diversity of allozyme loci in a sour cherry (2n=4×=32) germplasm collection. Segregation data was collected for alcohol dehydrogenase (ADH), glucose phosphate isomerase (GPI), isocitrate dehydrogenase (IDH), leucine amino peptidase (LAP), malate dehydrogenase (MDH), peroxidase (PX) (cathodal activity), phosphoglucomutase (PGM), 6-phosphogluconic dehydrogenase (6-PGD), and shikimate dehydrogenase (s k d h).Data suggest that alleles can be assigned to many of the enzyme systems being studied: ADH, GPI, IDH, LAP, PGM, and 6-PGD. Most loci are diallelic and often exhibit the unbalanced heterozygous condition. MDH, PX, and 6-PGD are highly polymorphic. Progeny segregation data fit disomic inheritance models, indicating that sour cherry is an allotetraploid.

scholarly journals Segregation and Linkage Relationships of Allozymes in Pinus Brutia Ten

2006 ◽  
Vol 55 (1-6) ◽  
pp. 155-160
Author(s):  
Nuray Kaya ◽  
K. Isik
Keyword(s):  
Seed Orchard ◽  
Mendelian Inheritance ◽  
Recombination Fraction ◽  
Starch Gel Electrophoresis ◽  
Mendelian Segregation ◽  
Pinus Brutia ◽  
Segregation Ratios ◽  
Starch Gel ◽  
Allozyme Loci ◽  
Linkage Relationships

Abstract Female gametophytes of Pinus brutia Ten. were analyzed to study Mendelian segregation and linkage among allozyme loci in a seed orchard composed of 28 clones. Isozyme variants of nine enzyme systems encoding 14 loci from megagametophytes were assayed by starch gel electrophoresis. While six of the 14 loci were monomorphic, the remaining eight were polymorphic. Analysis of observed segregation ratios of all polymorphic loci except for Sdh1, showed a good fit to the 1:1 ratios expected for Mendelian inheritance. Linkage relationships of the eight polymorphic allozyme loci were analyzed by testing 23 of the 28 possible two-locus combinations. Two-locus segregations in three pairs (Got2- Mdh1, Got2-Pgi2 and Pgd3-Sdh1) were significantly heterogeneous (P ≤ 0.05). Relatively weak linkage was observed between only one pair of genes (Adh2:Got2). Recombination fraction for Adh2:Got2 was found to be 0.24 (± 0.06).

Genetic divergence between branched and unbranched forms of the thecate hydroid Aglaophenia pluma

1992 ◽  
Vol 72 (4) ◽  
pp. 887-894 ◽  
Author(s):  
J. P. Thorpe ◽  
J. S. Ryland ◽  
P. F. S. Cornelius ◽  
J. A. Beardmore
Keyword(s):  
Genetic Differentiation ◽  
Strong Evidence ◽  
Genetic Divergence ◽  
Gel Electrophoresis ◽  
Distinct Species ◽  
Starch Gel Electrophoresis ◽  
Common Allele ◽  
South Wales ◽  
Starch Gel ◽  
High Level

Samples of branched and unbranched forms of the marine thecate hydroid Aglaophenia pluma (L.) (Hydrozoa, Plumulariidae) were collected from the western and eastern sides respectively of Carmarthen Bay (South Wales). Tissue from various colonies of each type was cleaned of epifauna and homogenized for horizontal starch gel electrophoresis. Useful results were obtained for 14 enzyme loci coding for a total of 11 different enzymes. Eleven of the 14 loci showed no common allele between the branched and unbranched forms. Nei's genetic identity was estimated as 0·18 and genetic distance as 1·7. Such a high level of genetic differentiation between morphotypes provides strong evidence that the populations are reproductively isolated and should be regarded as distinct species. It is suggested that the branched form may be Aglaophenia parvula Bale, a species until recently better known from the southern hemisphere. Morphological distinctions between the two species are discussed.

Allozyme divergence and evolutionary relationships among Populus deltoides, P. nigra, and P. maximowiczii

Genome ◽  
1990 ◽  
Vol 33 (1) ◽  
pp. 44-49 ◽  
Author(s):  
Om P. Rajora ◽  
Louis Zsuffa
Keyword(s):  
Gel Electrophoresis ◽  
Populus Deltoides ◽  
Genetic Identity ◽  
Starch Gel Electrophoresis ◽  
Root Tips ◽  
Frequency Distributions ◽  
Starch Gel ◽  
The Mean ◽  
Populus Species ◽  
Allozyme Loci

Horizontal starch gel electrophoresis of enzymes was used to study genetic divergence among Populus deltoides Marsh. (section Aigeiros Duby, Salicaceae), P. nigra L. (section Aigeiros), and P. maximowiczii Henry (section Tacamahaca Spach.) at 37 to 40 allozyme loci coding for 12 enzyme systems in root tips. These three Populus species were genetically distinct from each other. Populus deltoides, P. nigra, and P. maximowiczii had mutually exclusive alleles at two loci, and each of these species had unique alleles at many loci. Certain allozyme loci were detected only in one or two of these species. Frequency distributions of allozyme loci were bimodal with respect to genetic identity for comparisons between any two species. The mean genetic distance was 0.36 ± 0.10 between P. deltoides and P. nigra, 0.39 ± 0.09 between P. deltoides and P. maximowiczii, and 0.34 ± 0.10 between P. nigra and P. maximowiczii. The enzyme electrophoretic evidence indicated a monophyletic origin of the three Populus species.Key words: poplars, genetic identity and divergence, allozymes, molecular evolution, phylogenetics.

scholarly journals Human-driven genetic differentiation in a managed red deer population

2021 ◽  
Vol 67 (2) ◽  
Author(s):  
Gerald Reiner ◽  
C. Klein ◽  
M. Lang ◽  
H. Willems
Keyword(s):  
Gene Flow ◽  
Genetic Differentiation ◽  
Red Deer ◽  
Young Male ◽  
Genetic Exchange ◽  
Genetic Connectivity ◽  
Effective Population ◽  
Evolutionary Potential ◽  
Population Sizes ◽  
Populated Region

AbstractNineteen red deer areas in a densely populated region with a huge network of fenced motorways and the division into administrative management units (AMUs) with restricted ecological connectivity were investigated. In the season 2018/2019, a total of 1291 red deer samples (on average 68 per area) were collected and genotyped using 16 microsatellite markers. The results show a clear genetic differentiation between most of the AMUs. Fourteen AMUs may be combined into four regions with a considerable internal genetic exchange. Five areas were largely isolated or showed only a limited gene flow with neighbouring areas. Ten of the 19 AMUs had an effective population size below 100. Effective population sizes greater than 500–1000, required to maintain the evolutionary potential and a long-term adaptation potential, were not achieved by any of the studied AMUs, even when AMUs with an appreciable genetic exchange were aggregated. Substantial genetic differentiation between areas can be associated with the presence of landscape barriers hindering gene flow, but also with the maintenance of ‘red deer–free’ areas. Efforts to sustainably preserve the genetic diversity of the entire region should therefore focus on measures ensuring genetic connectivity. Opportunities for this goal arise from the establishment of game bridges over motorways and from the protection of young male stags migrating through the statutory ‘red deer–free’ areas.

Genetic structure and identification of Populus deltoides clones based on allozymes

Genome ◽  
1989 ◽  
Vol 32 (3) ◽  
pp. 440-448 ◽  
Author(s):  
Om P. Rajora
Keyword(s):  
Principal Components ◽  
Populus Deltoides ◽  
Principal Component ◽  
Starch Gel Electrophoresis ◽  
Root Tips ◽  
Polymorphic Loci ◽  
Multilocus Genotypes ◽  
Average Proportion ◽  
Starch Gel ◽  
Allozyme Loci

The allelic constitution of 30 Populus deltoides Marsh, clones selected in Canada and United States was determined for 37 allozyme loci coding for 12 enzyme systems in root tips. The enzymes were assayed by horizontal starch gel electrophoresis. One common allele was found at each locus in all clones. The interclonal allozyme variability was controlled by 12 loci. The average proportion of heterozygous loci per clone was 4.7%. There were 23 unique multilocus genotypes among 30 clones. On average, unique genotypes differed from each other at 4.33 loci. Principal-component analysis of clonal genotypes at 12 polymorphic loci indicated 8 loci to be the most differentiating for the clones. The first three principal components accounted for 47.6% of the total variation in 12 polymorphic loci. The ordination and grouping of the clones on principal components 1, 2, and 3 portrayed clonal relationships. Clones from the same small nautral population at Cherry Beach, Ont., and five clones of P. deltoides var. occidentalis were in the same group. There was no separation of clones of two varieties, P. deltoides var. deltoides and P. deltoides var. occidentalis. These results and their usefulness were discussed with reference to identification, certification, registration, and relationships of clones.Key words: Populus deltoides Marsh., allozymes, multilocus genotypes, clone characterization, clonal relationships, poplars.

scholarly journals Demographic Genetics of Brown Trout (Salmo trutta) and Estimation of Effective Population Size From Temporal Change of Allele Frequencies

Genetics ◽  
1996 ◽  
Vol 143 (3) ◽  
pp. 1369-1381 ◽  
Author(s):  
Per Erik Jorde ◽  
Nils Ryman
Keyword(s):  
Allele Frequency ◽  
Brown Trout ◽  
Salmo Trutta ◽  
Natural Populations ◽  
Effective Size ◽  
Effective Population ◽  
Frequency Shifts ◽  
Brown Trout Salmo Trutta ◽  
Population Sizes ◽  
Allozyme Loci

Abstract We studied temporal allele frequency shifts over 15 years and estimated the genetically effective size of four natural populations of brown trout (Salmo trutta L.) on the basis of the variation at 14 polymorphic allozyme loci. The allele frequency differences between consecutive cohorts were significant in all four populations. There were no indications of natural selection, and we conclude that random genetic drift is the most likely cause of temporal allele frequency shifts at the loci examined. Effective population sizes were estimated from observed allele frequency shifts among cohorts, taking into consideration the demographic characteristics of each population. The estimated effective sizes of the four populations range from 52 to 480 individuals, and we conclude that the effective size of natural brown trout populations may differ considerably among lakes that are similar in size and other apparent characteristics. In spite of their different effective sizes all four populations have similar levels of genetic variation (average heterozygosity) indicating that excessive loss of genetic variability has been retarded, most likely because of gene flow among neighboring populations.

scholarly journals Genetic variation of Abies alba Mill. in Polish part of Sudety Mts.

2014 ◽  
Vol 70 (3) ◽  
pp. 215-219 ◽  
Author(s):  
Andrzej Lewandowski ◽  
Maciej Filipiak ◽  
Jarosław Burczyk
Keyword(s):  
Gel Electrophoresis ◽  
Abies Alba ◽  
Silver Fir ◽  
Allozyme Polymorphism ◽  
Starch Gel Electrophoresis ◽  
Expected Heterozygosity ◽  
Starch Gel ◽  
The Mean ◽  
Allozyme Loci ◽  
Two Populations

The genetic structure of silver fir (<em>Abies alba</em> Mill.) was investigated among 8 populations from Sudety Mts. and 2 additional populations from other parts of Poland. Nine enzyme systems controlled by 13 allozyme loci were analyzed using starch gel electrophoresis. The mean expected heterozygosity, ranging from 0.06 to 0.11 and was lower compared to that found in other conifers. The mean genetic distance among all silver fir populations was 0.005. The Sudeten group of populations appeared to be genetically different from the two populations from other parts of Poland, indicating that at least two different centers are responsible for the current distribution of allozyme polymorphism in the tested populations.

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