scholarly journals Selection for Ethanol Tolerance in Two Populations of Drosophila Melanogaster Segregating Alcohol Dehydrogenase Allozymes

1979 ◽  
Vol 32 (3) ◽  
pp. 387 ◽  
Author(s):  
John B Gibson ◽  
NigeI Lewis ◽  
MichaeI Adena ◽  
Susan R Wilson
Keyword(s):  
Drosophila Melanogaster ◽  
Alcohol Dehydrogenase ◽  
Ethanol Tolerance ◽  
Selection For ◽  
Two Populations

Selection for ethanol tolerance was equally successful in two populations of D. melanogaster in both of which the frequency of AdhF was 0�5 at the start of the experiment.

scholarly journals Selection for ethanol tolerance and Adh allozymes in natural populations of Drosophila melanogaster

1980 ◽  
Vol 36 (1) ◽  
pp. 11-15 ◽  
Author(s):  
D. A. Hickey ◽  
Michael D. McLean
Keyword(s):  
Drosophila Melanogaster ◽  
Alcohol Dehydrogenase ◽  
Ethanol Tolerance ◽  
Natural Populations ◽  
Southern Ontario ◽  
Selection For ◽  
Low Alcohol

SUMMARYAlcohol dehydrogenase (Adh) allozyme frequencies and tolerance of adult flies to ethanol were measured in population samples of D. melanogaster from a winery in Southern Ontario. Samples were also tested from a number of non-winery sites. Adhfast frequencies decrease as one moves away from the winery, but this drop in allozyme frequency is statistically significant only for those areas that are more than 3 km distant from the winery. Tolerance of adult flies to ethanol also differed between winery and non-winery populations, but these differences were not statistically significant. The data presented here may help to resolve the seeming conflict between the two previous studies of Adh allozyme frequencies in natural populations from highand low-alcohol environments.

scholarly journals Alcohol dehydrogenase activity in Drosophila melanogaster: a quantitative character

1975 ◽  
Vol 26 (1) ◽  
pp. 81-93 ◽  
Author(s):  
R. D. Ward
Keyword(s):  
Drosophila Melanogaster ◽  
Alcohol Dehydrogenase ◽  
Dehydrogenase Activity ◽  
Structural Gene ◽  
Genetic Background ◽  
Quantitative Character ◽  
Alcohol Dehydrogenase Activity ◽  
Activity Modifiers ◽  
Selection For ◽  
Adh Activity

SUMMARYAlcohol dehydrogenase activity in Drosophila melanogaster may be considered as a quantitative character, since it shows many features typically associated with such traits. Although strains with the electrophoretically fast phenotype generally have activities greater than those with the slow phenotype, presumably reflecting differences in the nucleotide sequences of the structural alleles, within each electrophoretic class there is considerable variation in activity. The expression of the structural gene, in terms of ADH activity, is to some extent regulated by its genetic background. Strains homozygous for particular structural alleles respond to divergent directional selection for ADH activity. Modifiers have been located to the X, second and third chromosomes.

scholarly journals Genetic differences between populations of Drosophila melanogaster for a quantitative trait: I. Laboratory populations

1973 ◽  
Vol 22 (1) ◽  
pp. 51-68 ◽  
Author(s):  
C. López-Fanjul ◽  
W. G. Hill
Keyword(s):  
Drosophila Melanogaster ◽  
Gene Frequency ◽  
Total Response ◽  
Selected Lines ◽  
Synthetic Populations ◽  
Bristle Number ◽  
Laboratory Populations ◽  
Selection For ◽  
Different Origins ◽  
Two Populations

SUMMARYAn experiment was carried out to test whether two laboratory cage populations of Drosophila melanogaster from different origins (Kaduna and Pacific) differed in the genes for sternopleural bristle number. The means, variances and heritabilities of the two populations and the synthetic formed from crosses between them were very similar.Selection for low bristle number was practised in small replicate lines, six of each pure population and nine of the synthetic. On average, Pacific responded to selection rather more rapidly than either Kaduna or the synthetic, but there was little difference in the limit achieved.Crosses between replicates within populations were made and selection continued, and these lines subsequently crossed between populations and reselected. Additional response was obtained by this procedure but the crosses between the replicates of the pure and synthetic populations attained similar selection limits.An analysis of effects of individual chromosomes from the selected lines on bristle number indicated that the contribution of each chromosome to total response was about the same in Pacific, Kaduna and the synthetic.It is concluded that differences in gene frequency, rather than the presence or absence of particular alleles, are mainly responsible for the differences observed between the populations.

scholarly journals GENETIC DIVERGENCE UNDER UNIFORM SELECTION. II. DIFFERENT RESPONSES TO SELECTION FOR KNOCKDOWN RESISTANCE TO ETHANOL AMONG DROSOPHILA MELANOGASTER POPULATIONS AND THEIR REPLICATE LINES

Genetics ◽  
1986 ◽  
Vol 114 (1) ◽  
pp. 145-164
Author(s):  
Frederick M Cohan ◽  
Ary A Hoffmann
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Drift ◽  
Genetic Background ◽  
Ethanol Tolerance ◽  
Natural Populations ◽  
Selection Response ◽  
Genetic Differences ◽  
Knockdown Resistance ◽  
Selected Lines ◽  
Selection For

ABSTRACT We have tested the hypothesis that genetic differences among conspecific populations may result in diverse responses to selection, using natural populations of Drosophila melanogaster. Selection for ethanol tolerance in a tube measuring knockdown resistance was imposed on five West Coast populations. In 24 generations the selected lines increased their mean knockdown times, on average, by a factor of 2.7. An initially weak latitudinal cline was steepened by selection. The two southernmost populations showed the same increases in the selected character, but differed consistently in their correlated responses in characters related to ethanol tolerance. This result indicates that the populations responded to selection by different genetic changes. Selection decreased female body weight and increased resistance to acetone, suggesting components of the response unrelated to ethanol metabolism. The Adhs allele was favored by selection in all populations at the onset, but increased in frequency only in the selected lines of the southernmost population. There was a correlation between latitude and Adh frequency changes, suggesting that fitnesses of the Adh alleles were dependent on the genetic background. Genetic background also had a large effect on the loss of fitness due to selection. Genetic drift between replicate lines caused more variation in selection response than initial genetic differences between populations. This result demonstrates the importance of genetic drift in divergence among natural populations undergoing uniform selection, since the effective population sizes approached those of small natural populations. Drift caused greater divergence between selected replicates than control replicates. Implications of this result for the genetic model of selection response are discussed.

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