scholarly journals GENETIC VARIATION FOR DISPERSAL BY DROSOPHILA PSEUDOOBSCURA AND DROSOPHILA PERSIMILIS

Genetics ◽  
1986 ◽  
Vol 112 (2) ◽  
pp. 229-235
Author(s):  
Louis Bernard Klaczko ◽  
Charles E Taylor ◽  
Jeffrey R Powell
Keyword(s):  
Genetic Variation ◽  
Spatial Variation ◽  
Habitat Preferences ◽  
Drosophila Pseudoobscura ◽  
Heterogeneous Environment ◽  
Dispersal Behavior ◽  
Drosophila Persimilis ◽  
Different Strains

ABSTRACT Release-recapture experiments using Drosophila pseudoobscura and D. persimilis strains of different karyotypes were performed in a heterogeneous environment. The heterogeneity was due to both spatial variation and the species of yeast used to attract the released flies. No karyotypic-specific habitat preferences were detected. However, in all releases, different strains did behave differently with respect to one or both of the heterogeneous factors. These results indicate there is variation for dispersal behavior in these species that is most likely based on genotype-dependent habitat preferences.

scholarly journals Disentangling the Effect of Local and Global Spatial Variation on a Mosquito-Borne Infection in a Neotropical Heterogeneous Environment

2010 ◽  
Vol 82 (2) ◽  
pp. 194-201 ◽  
Author(s):  
María-Eugenia Grillet ◽  
Jesús Berti ◽  
Roberto Barrera ◽  
Marie-Josée Fortin ◽  
Juan-Eudes Martínez
Keyword(s):  
Spatial Variation ◽  
Heterogeneous Environment

PHENOTYPIC CONSEQUENCES OF GENETIC VARIATION IN A GYNOGENETIC COMPLEX OF PHOXINUS EOS-NEOGAEUS CLONAL FISH (PISCES: CYPRINIDAE) INHABITING A HETEROGENEOUS ENVIRONMENT

Evolution ◽  
2004 ◽  
Vol 58 (6) ◽  
pp. 1261 ◽  
Author(s):  
Matthew R. Doeringsfeld ◽  
Isaac J. Schlosser ◽  
John F. Elder ◽  
Donald P. Evenson
Keyword(s):  
Genetic Variation ◽  
Heterogeneous Environment

scholarly journals NATURAL SELECTION VS. RANDOM DRIFT: EVIDENCE FROM TEMPORAL VARIATION IN ALLELE FREQUENCIES IN NATURE

Genetics ◽  
1985 ◽  
Vol 111 (3) ◽  
pp. 517-554
Author(s):  
Laurence D Mueller ◽  
Lorraine G Barr ◽  
Francisco J Ayala
Keyword(s):  
Natural Selection ◽  
Strong Evidence ◽  
Allele Frequencies ◽  
Drosophila Pseudoobscura ◽  
Frequency Variation ◽  
Random Drift ◽  
Napa County ◽  
Environmental Variations ◽  
Monthly Sample ◽  
Drosophila Persimilis

ABSTRACT We have obtained monthly samples of two species, Drosophila pseudoobscura and Drosophila persimilis, in a natural population from Napa County, California. In each species, about 300 genes have been assayed by electrophoresis for each of seven enzyme loci in each monthly sample from March 1972 to June 1975. Using statistical methods developed for the purpose, we have examined whether the allele frequencies at different loci vary in a correlated fashion. The methods used do not detect natural selection when it is deterministic (e.g., overdominance or directional selection), but only when alleles at different loci vary simultaneously in response to the same environmental variations. Moreover, only relatively large fitness differences (of the order of 15%) are detectable. We have found strong evidence of correlated allele frequency variation in 13-20% of the cases examined. We interpret this as evidence that natural selection plays a major role in the evolution of protein polymorphisms in nature.

scholarly journals Variation under domestication in animal models: the case of the Mexican axolotl

BMC Genomics ◽  
2020 ◽  
Vol 21 (1) ◽  
Author(s):  
María Torres-Sánchez
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Animal Models ◽  
Model Organisms ◽  
Laboratory Animals ◽  
Reproducible Research ◽  
Biological Research ◽  
Research Knowledge ◽  
Mexican Axolotl ◽  
Different Strains

Abstract Background Species adaptation to laboratory conditions is a special case of domestication that has modified model organisms phenotypically and genetically. The characterisation of these changes is crucial to understand how this variation can affect the outcome of biological experiments. Yet despite the wide use of laboratory animals in biological research, knowledge of the genetic diversity within and between different strains and populations of some animal models is still scarce. This is particularly the case of the Mexican axolotl, which has been bred in captivity since 1864. Results Using gene expression data from nine different projects, nucleotide sequence variants were characterised, and distinctive genetic background of the experimental specimens was uncovered. This study provides a catalogue of thousands of nucleotide variants along predicted protein-coding genes, while identifying genome-wide differences between pigment phenotypes in laboratory populations. Conclusions Awareness of the genetic variation could guide a better experimental design while helping to develop molecular tools for monitoring genetic diversity and studying gene functions in laboratory axolotls. Overall, this study highlights the cross-taxa utility that transcriptomic data might have to assess the genetic variation of the experimental specimens, which might help to shorten the journey towards reproducible research.

Light intensity as a factor in the choice of an oviposition site by Drosophila pseudoobscura and Drosophila persimilis

1983 ◽  
Vol 25 (4) ◽  
pp. 370-377 ◽  
Author(s):  
Dennis J. Wogaman ◽  
Marvin B. Seiger
Keyword(s):  
Light Intensity ◽  
Genetic Variability ◽  
Sibling Species ◽  
Light Response ◽  
Drosophila Pseudoobscura ◽  
Isofemale Lines ◽  
Sympatric Populations ◽  
Allopatric Populations ◽  
Behavioral Differentiation ◽  
Drosophila Persimilis

Light preferences for ovipositing of the sibling species Drosophila pseudoobscura and D. persimilis were measured in a multichoice chamber. Behavioral differentiation was found among sympatric populations of D. pseudoobscura and D. persimilis and between allopatric populations of D. pseudoobscura. Differences among isofemale lines within populations indicated genetic variability for the behavior. Both D. pseudoobscura populations were less fecund in a uniform light environment than in the multichoice environment while D. persimilis showed no difference in fecundity in the two environments. The patterns for general photoresponse and ovipositional light response were shown to be different for each population. Thus, the motivation to oviposit may affect photopreference differentially in each population.

scholarly journals ‘Overcompensation’ at an enzyme locus in Drosophila pseudoobscura

1980 ◽  
Vol 36 (1) ◽  
pp. 57-67 ◽  
Author(s):  
Mirjana Toŝić ◽  
Francisco J. Ayala
Keyword(s):  
High Variability ◽  
High Density ◽  
The Other ◽  
Drosophila Pseudoobscura ◽  
Frequency Dependent ◽  
Frequency Dependent Selection ◽  
Single Genotype ◽  
Different Strains ◽  
Fourth Kind ◽  
Better Than

SUMMARYThe experiments reported in this paper are primarily addressed to test the hypothesis of overcompensation; i.e. whether polymorphic populations exploit limiting environmental resources better than populations uniform for a single genotype. Overcomposition is an ecological consequence of some models of frequency-dependent selection. Secondarily, the experiments investigate whether overdominance exists at the Mdh-2 locus in Drosophila pseudoobscura.Two types of experimental populations are established: ‘low-variability’ populations, in which all flies in a culture are offspring from only two laboratory strains; ‘high-variability’ populations, in which the flies in a culture are derived from 20 different strains. However, the overall degree of individual heterozygosity is the same in both types of populations. Three kinds of populations with respect to the Mdh-2 locus are established within each type; two are homozygous for either the 100 or the 112 allele, the third is heterozygous. A fourth kind of population exists among the high-variability populations; namely, populations in which all three Mdh-2 genotypes are present. The experiments are done at two densities; one quasi-optimal, the other highly competitive.Populations with high overall levels of genetic variation consistently produce more flies than low-variability populations. The differences are significant at the low, but not at the high, density. Moreover, populations polymorphic for the Mdh-2 locus generally produce more flies than populations having only one Mdh-2 genotype. At high density, the Mdh-2 polymorphic populations have greater productivity than populations with anyone of the three genotypes, and the differences are statistically significant when the polymorphic populations are compared with either one of the two homozygotes or with the average of all three genotypes. In brief, overcompensatory effects – which may account for frequency-dependent selection – are observed in the experiment and may be a common phenomenon in nature.Populations in which all individuals are heterozygous at the Mdh-2 locus produce in every case more flies than populations with only homozygotes for one or the other allele. The superiority of the heterozygotes is statistically significant for all comparisons at low density, but at high density it is statistically significant for the comparison with the homozygote rarer in nature and only in low variability populations.

scholarly journals Unusual pattern of single nucleotide polymorphism at the exuperantia2 locus of Drosophila pseudoobscura

2003 ◽  
Vol 82 (2) ◽  
pp. 101-106 ◽  
Author(s):  
SOOJIN YI ◽  
BRIAN CHARLESWORTH
Keyword(s):  
Nucleotide Diversity ◽  
Drosophila Pseudoobscura ◽  
Nucleotide Polymorphism ◽  
Haplotype Group ◽  
Single Nucleotide ◽  
Genetic Studies ◽  
Distinct Haplotype ◽  
Dna Sequence Variation ◽  
Replacement Site ◽  
Drosophila Persimilis

We have investigated the pattern of DNA sequence variation at the exuperantia2 locus in Drosophila pseudoobscura. This adds to the increasing dataset of genetic variation in D. pseudoobscura, a useful model species for evolutionary genetic studies. The level of silent site nucleotide diversity and the divergence from an outgroup Drosophila miranda are comparable with those for other X-linked loci. One peculiar pattern at the exu2 locus of D. pseudoobscura is a complete linkage disequilibrium between two SNPs, one of which is a replacement site. As a result, there are two distinct haplotype groups in our dataset. Based upon the comparisons with the outgroup sequences from D. miranda and Drosophila persimilis, we show that the newly derived haplotype group has lower diversity than the ancestral haplotype group. The pattern of protein evolution at exu2 shows some deviation from the neutral model. Together, these and other characteristics of the exu2 locus suggest the action of selection on the pattern of SNP variation, consistent with a partial selective sweep associated with the newly derived haplotype.

Genetic variation for monomer–dimer equilibria of esterase-5 in Drosophila pseudoobscura, Drosophila persimilis, and Drosophila miranda

1984 ◽  
Vol 26 (3) ◽  
pp. 374-381 ◽  
Author(s):  
David R. Townsend ◽  
Rama S. Singh
Keyword(s):  
Electrophoretic Mobility ◽  
Enzyme Stability ◽  
Good Deal ◽  
The Other ◽  
Drosophila Pseudoobscura ◽  
Closely Related Species ◽  
Speciation Event ◽  
Population Polymorphism ◽  
Drosophila Persimilis ◽  
Close Relatives

Esterase-5 is a highly polymorphic enzyme in Drosophila pseudoobscura and its close relatives. Numerous alleles have been identified by employing a number of physicochemical properties of the enzyme (e.g. electrophoretic mobility, enzyme stability, subunit dimerization, and variation in monomer–dimer equilibrium). Variation in the monomer–dimer equilibrium of esterase-5 leads to differences in electrophoretic mobility of monomers produced by dimers all of which have the same mobility. In this report we have used this criterion to study variation within, as well as between, four closely related species: D. pseudoobscura pseudoobscura, D. pseudoobscura bogotana. D. persimilis, and D. miranda. All lines were characterized for esterase-5 monomer and dimer mobility at a number of gel concentrations and the comparison was made by plotting log10 monomer – dimer mobility as a function of gel concentration. No variation was found within D. p. pseudoobscura or D. p. bogotana but some variation (two distinct alleles) did occur in D. persimilis. Drosophila miranda is segregating for two alleles, one of which is fixed in D. pseudoobscura and the other one is common in D. persimilis. Thus it seems that the variation in monomer–dimer equilibrium is a rather conservative criterion and that the variation in D. miranda is a good deal older than the speciation event(s) which gave rise to D. miranda and the lineage leading to D. pseudoobscura and D. persimilis.Key words: esterase-5, Drosophila pseudoobscura, monomer–dimer equilibrium, population, polymorphism, speciation, electrophoresis.

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