scholarly journals The Genetic Structure of Natural Populations of Drosophila melanogaster. XX. Comparison of Genotype-Environment Interaction in Viability Between a Northern and a Southern Population

Genetics ◽  
1987 ◽  
Vol 117 (2) ◽  
pp. 245-254
Author(s):  
Toshiyuki Takano ◽  
Shinichi Kusakabe ◽  
Terumi Mukai
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Variance ◽  
Additive Genetic Variance ◽  
Natural Populations ◽  
Environment Interaction ◽  
Southern Population ◽  
Genotypic Variance ◽  
Diversifying Selection ◽  
Genotype Environment Interaction ◽  
Interaction Variance

ABSTRACT In order to examine the operation of diversifying selection as the maintenance mechanism of excessive additive genetic variance for viability in southern populations in comparison with northern populations of Drosophila melanogaster, two sets of experiments were conducted using second chromosomes extracted from the Ogasawara population (a southern population in Japan) and from the Aomori population (a northern population in Japan). Chromosomal homozygote and heterozygote viabilities were estimated in eight kinds of artificially produced breeding environments. The main findings in the present investigation are as follows: (1) Significant genotype-environment interaction was observed using chromosomes extracted from the Ogasawara population. Indeed, the estimate of the genotype-environment interaction variance for heterozygotes was significantly larger than that of the genotypic variance. On the other hand, when chromosomes sampled from the Aomori population were examined, that interaction variance was significant only for homozygotes and its value was no more than one quarter of that for the chromosomes from the Ogasawara population. (2) The average genetic correlation between any two viabilities of the same lines estimated in the eight kinds of breeding environments for the chromosomes sampled from the Ogasawara population was smaller than that for the chromosomes from the Aomori population both in homozygotes and in heterozygotes, especially in the latter. (3) The stability of heterozygotes over homozygotes against fluctuations of environmental conditions was seen in the chromosomes from the Ogasawara population, but not from the Aomori population. (4) From the excessive genotype-environment interaction variance compared with the genotypic variance in heterozygotes, it was suggested for the chromosomes from the Ogasawara population that the reversal of viability order between homozygotes took place in some environments at the locus level. On the basis of these findings, it is strongly suggested that diversifying selection is operating in a southern population of D. melanogaster on some of the viability polygenes which are probably located outside the structural loci, and the excessive additive genetic variance of viability in southern populations is maintained by this type of selection.

THE GENETIC STRUCTURE OF NATURAL POPULATIONS OF DROSOPHILA MELANOGASTER. XIX. GENOTYPE-ENVIRONMENT INTERACTION IN VIABILITY

Genetics ◽  
1985 ◽  
Vol 111 (1) ◽  
pp. 43-55
Author(s):  
Hidenori Tachida ◽  
Terumi Mukai
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Variance ◽  
Culture Media ◽  
Additive Genetic Variance ◽  
Natural Populations ◽  
Environment Interaction ◽  
Diversifying Selection ◽  
Genotype Environment Interaction ◽  
Significant Difference ◽  
Experimental Findings

ABSTRACT To investigate whether or not an excess of additive genetic variance for viability detected in southern natural populations of Drosophila melanogaster was created by diversifying selection, genotype-environment interaction was tested as follows. (1) Two karyotype chromosomes were used: 61 second chromosomes with the standard karyotype and 63 second chromosomes carrying In(2L)t. Their homozygote viabilities were larger than 50% of the average viability of random heterozygotes. (2) The effects of two factors (culture media and yeasts) were examined at three levels (the culture media: tomato, corn and banana; and the yeasts: sake, brewer's and baker's). The results of 16 three by three factorial experiments by the Cy method in the same karyotype groups for relative viabilities of homozygotes and heterozygotes elucidated the following findings: (1) there was no significant difference between the two karyotype groups, (2) the variance components of genotype-environment interaction were highly significant, (3) the variance component of heterozygotes was significantly smaller than that of homozygotes. From the experimental findings and previous results, diversifying selection in natural populations acting on viability polygenes to increase the additive genetic variance was suggested. The relation of the present result to protein polymorphism is also discussed.

scholarly journals Temporal uniformity of the spontaneous mutational variance of quantitative traits in Drosophila melanogaster

2000 ◽  
Vol 75 (1) ◽  
pp. 47-51 ◽  
Author(s):  
AURORA GARCÍA-DORADO ◽  
JESUS FERNÁNDEZ ◽  
CARLOS LÓPEZ-FANJUL
Keyword(s):  
Drosophila Melanogaster ◽  
Morphological Traits ◽  
Quantitative Traits ◽  
Wing Length ◽  
Environment Interaction ◽  
Genotype Environment Interaction ◽  
Bristle Number ◽  
Sib Mating ◽  
Mutational Variance ◽  
Interaction Variance

Spontaneous mutations were allowed to accumulate over 209 generations in more than 100 lines, all of them independently derived from a completely homozygous population of Drosophila melanogaster and subsequently maintained under strong inbreeding (equivalent to full-sib mating). Traits scored were: abdominal (AB) and sternopleural (ST) bristle number, wing length (WL) and egg-to-adult viability (V). On two occasions – early (generations 93–122) and late (generations 169–209) – ANOVA estimates of the mutational variance and the mutational line × generation interaction variance were obtained. Mutational heritabilities of morphological traits ranged from 2 × 10−4 to 2 × 10−3 and the mutational coefficient of variation of viability was 0·01. For AB, WL and V, temporal uniformity of the mutational variance was observed. However, a fluctuation of the mutational heritability of ST was detected and could be ascribed to random genotype × environment interaction.

scholarly journals Variance component analysis for viability in an isolated population of Drosophila melanogaster

1983 ◽  
Vol 42 (2) ◽  
pp. 207-217 ◽  
Author(s):  
Hidenori Tachida ◽  
Muneo Matsuda ◽  
Shin-Ichi Kusakabe ◽  
Terumi Mukai
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Variance ◽  
Balancing Selection ◽  
Additive Genetic Variance ◽  
Diallel Cross ◽  
Variance Component Analysis ◽  
Logarithmic Scale ◽  
Dominance Variance ◽  
Diversifying Selection ◽  
Partial Diallel

SUMMARYUsing the 602 second chromosome lines extracted from the Ishigakijima population of Drosophila melanogaster in Japan, partial diallel cross experiments (Design II of Comstock & Robinson, 1952) were carried out, and the additive genetic variance and the dominance variance of viability were estimated. The estimated value of the additive genetic variance is 0·01754±0·00608, and the dominance variance 0·00151±0·00114, using a logarithmic scale. Since the value of the additive genetic variance is much larger than expected under mutation–selection balance although the dominance variance is compatible with it, we speculate that in the Ishigakijima population some type of balancing selection must be operating to maintain the genetic variability with respect to viability at a minority of loci. As candidates for such selection, overdominance, frequency-dependent selection, and diversifying selection are considered, and it is suggested that diversifying selection is the most probable candidate for increasing the additive genetic variance.

Genetic Variation and Causes of Genotype-Environment Interaction in the Body Size of Blue Tit (Parus caeruleus)

Genetics ◽  
1998 ◽  
Vol 148 (3) ◽  
pp. 1233-1244 ◽  
Author(s):  
Juha Merilä ◽  
James D Fry
Keyword(s):  
Genetic Variation ◽  
Body Size ◽  
Genetic Variance ◽  
Natural Populations ◽  
The Body ◽  
Environment Interaction ◽  
Parus Caeruleus ◽  
Genotype Environment Interaction ◽  
The Poor ◽  
Good Environment

Abstract In several studies of natural populations of birds, the heritability of body size estimated by parent-offspring regression has been lower when offspring have developed in poor feeding regimens than when they developed in good feeding regimens. This has led to the suggestion that adaptation under poor regimens may be constrained by lack of genetic variation. We examined the influence of environmental conditions on expression of genetic variation in body size of nestling blue tits (Parus caeruleus) by raising full sibs in artificially reduced and enlarged broods, corresponding to good and poor feeding regimens, respectively. Individuals grown in the poor regimen attained smaller body size than their sibs grown in the good regimen. However, there was among-family variation in response to the treatments—i.e., genotype-environment interactions (GEIs). Partitioning the GEI variance into contributions attributable to (1) differences in the among-family genetic variance between the treatments and (2) imperfect correlation of genotypic values across treatments identified the latter as the main cause of the GEI. Parent-offspring regressions were not significantly different when offspring were reared in the good environment (h2 = 0.75) vs. when they were reared in the poor environment (h2 = 0.63). Thus, there was little evidence that genetic variance in body size was lower under the poor conditions than under the good conditions. These results do not support the view that the genetic potential for adaptation to poor feeding conditions is less than that for adaptation to good conditions, but they do suggest that different genotypes may be favored under the different conditions.

scholarly journals The genetic structure of natural populations of Drosophila melanogaster. XXIV. Effects of hybrid dysgenesis on the components of genetic variance of variability.

Genetics ◽  
1991 ◽  
Vol 127 (3) ◽  
pp. 545-552
Author(s):  
D S Suh ◽  
T Mukai
Keyword(s):  
Drosophila Melanogaster ◽  
Population Genetic ◽  
Genetic Parameters ◽  
Genetic Variance ◽  
Additive Genetic Variance ◽  
Natural Populations ◽  
Deleterious Mutations ◽  
Degree Of Dominance ◽  
Population Genetic Parameters ◽  
P Type

Abstract Eight hundred second chromosomes were extracted from the Ishigakijima population, one of the southernmost populations of Drosophila melanogaster in Japan. Half of them were extracted in Native cytoplasm (P-type), and half in Foreign cytoplasm (M-type). Various population-genetic parameters, including the frequency of lethal-carrying second chromosomes (Q = 0.235 for the Native; 0.218 for the Foreign), the allelism rate of lethal second chromosome (Ic = 0.0217 for the Native; 0.0134 for the Foreign), the homozygous detrimental and lethal loads (D = 0.179 for the Native; 0.270 for the Foreign; L = 0.262 for the Native; 0.240 for the Foreign), the average degree of dominance of mildly deleterious mutations (ĥE = 0.244 for the Native; 0.208 for the Foreign), and the components of genetic variance for viability [additive (sigma A2) and dominance (sigma D2)](ŝigma A2 = 0.0187 for the Native; 0.0172 for the Foreign; ŝigma D2 = 0.0005 for the Native; 0.0009 for the Foreign) were estimated. The data indicate that D was significantly larger and hE was significantly smaller in the Foreign cytoplasm. However, the estimates of additive and dominance variances were not significantly different between the two cytoplasms. The additive genetic variance for viability in the Ishigakijima population was greater than expected on the basis of mutation-selection balance confirming previous studies on papers of D. melanogaster in warm climates.

STUDIES ON NATURAL POPULATIONS OF DROSOPHILA. XII. HETEROSIS AND FITNESS CHARACTERS IN HYBRIDS BETWEEN DIFFERENT POPULATIONS OF DROSOPHILA MELANOGASTER

1970 ◽  
Vol 12 (4) ◽  
pp. 695-710 ◽  
Author(s):  
A. O. Tantawy ◽  
M. R. El-Helw
Keyword(s):  
Drosophila Melanogaster ◽  
Inbred Line ◽  
Egg Production ◽  
Natural Populations ◽  
Relative Fitness ◽  
Environment Interaction ◽  
Population Variance ◽  
Genotype Environment Interaction ◽  
The Poor ◽  
Different Populations

Three different unrelated natural populations of Drosophila melanogaster from Scotland, Japan and Egypt, as well a highly inbred line, were the basis of the present study. Crosses were made within and between natural populations and between each of the natural populations and the highly inbred line to obtain the parental, F1 and F2 generations and their relative fitness studied at 15°, 25° and 28 °C.The F1 interpopulation hybrids were superior to both parents in egg production, percentage emergence and longevity of adults in most of the crosses. Heterosis tended to be higher at 15° and 28° than at 25 °C. The F2 in all crosses was inferior to the F1 and also inferior to one or both parents. In crossing the inbred line with any of the natural populations, the F1 generally showed higher heterosis than that of the interpopulation hybrids; the F2 was also inferior to the F1 but superior to the inbred parent.Significant genotype-environment interaction was detected, indicating the differences in sensitivity to temperature in each population. Variance of any-given fitness character of a superior population at a given temperature was often smaller than the poor genotype. There was a decline in the coefficient of variation in the F1 generation and an increase in the F2's.

Genetic parameters of growth characters in Salixviminalis grown in Sweden

1994 ◽  
Vol 24 (9) ◽  
pp. 1960-1969 ◽  
Author(s):  
Ann Christin Rönnberg-Wästljung ◽  
Urban Gullberg ◽  
Christina Nilsson
Keyword(s):  
Genetic Parameters ◽  
Genetic Variance ◽  
Clay Soil ◽  
Additive Genetic Variance ◽  
Environment Interaction ◽  
Narrow Sense Heritability ◽  
Genotype Environment Interaction ◽  
Heavy Clay ◽  
The Impact ◽  
Growth Characters

Forty families of Salixviminalis L. from an eight by eight factorial crossing were planted in contrasting environments to estimate genetic additive, dominance, and epistatic variances and to estimate the impact of genotype–environment interaction. From each family, 14 seed plants were vegetatively propagated. The material was planted in two contrasting soils, heavy clay soil and sandy soil, and in two contrasting nutrient availabilities, high and low. The nutrient experiment was harvested annually for 3 years. The clay–sand experiment was harvested in the 1st, 4th, and 6th year. Height, diameter, weight, and number of shoots were measured. Additive genetic variance was found, but there were large standard deviations in many of the estimates, especially in the nutrient experiment. Dominance and epistatic variances of greater significance were found for weight characters in the clay–sand experiment. Narrow-sense heritability estimates varied, with the highest estimate being 0.34. Genotype–environment interaction seems to be of greatest importance in the establishment years in the soil contrast but of increasing importance in the nutrient contrast. Breeding strategies in connection with these findings are discussed.

scholarly journals A comparison of the interaction, with two types of environment, of pure strains or strain crosses of poultry

1963 ◽  
Vol 4 (3) ◽  
pp. 370-381 ◽  
Author(s):  
P. Hull ◽  
R. S. Gowe ◽  
S. B. Slen ◽  
R. D. Crawford
Keyword(s):  
Body Weight ◽  
Sexual Maturity ◽  
Environmental Effect ◽  
Egg Production ◽  
Genetic Variance ◽  
Environment Interaction ◽  
Reciprocal Crosses ◽  
Genotype Environment Interaction ◽  
Six Traits ◽  
Interaction Variance

In these experiments comparisons were made between the magnitude of the interaction of ‘pure’ strains and strain crosses of poultry with two types of environments—location effects and a restricted-feed versus a full-feed rearing programme. The ‘pure’ strains were closed flocks of White Leghorns that had been selected for increased egg production, while the strain crosses were the reciprocal crosses of all combinations of these pure strains. Data from four separate experiments in four consecutive years used for this study involved 8320 laying birds. Six traits of the adult laying birds were used for these analyses.It was expected that the ‘pure’ strains would differ in performance amongst themselves to a greater extent than the strain crosses, and for the two traits, body-weight at housing and sexual maturity, this was found to be the case in three out of four years. These two traits were affected to the greatest extent by the rearing treatment. Also, the genotype-environment interaction variance was found to be significant and of important magnitude relative to the genetic variance for these two traits. Where the environmental effect was found to be smaller, the interaction variance made up a smaller proportion of the genetic variance.

scholarly journals Quantitative genetics of response to competitors in Nemophila menziesii: a field experiment.

Genetics ◽  
1995 ◽  
Vol 139 (1) ◽  
pp. 397-406 ◽  
Author(s):  
R G Shaw ◽  
G A Platenkamp ◽  
F H Shaw ◽  
R H Podolsky
Keyword(s):  
Field Experiment ◽  
Genetic Variance ◽  
Plant Density ◽  
Additive Genetic Variance ◽  
Natural Populations ◽  
Plant Size ◽  
Heterogeneous Environments ◽  
Environmental Complexity ◽  
Sources Of Variation ◽  
Nemophila Menziesii

Abstract Recent investigations of evolution in heterogeneous environments have begun to accommodate genetic and environmental complexity typical of natural populations. Theoretical studies demonstrate that evolution of polygenic characters depends heavily on the genetic interdependence of the expression of traits in the different environments in which selection occurs, but information concerning this issue is scarce. We conducted a field experiment to assess the genetic variability of the annual plant Nemophila menziesii in five biotic regimes differing in plant density and composition. Significant, though modest, additive genetic variance in plant size was expressed in particular treatments. Evidence of additive genetic tradeoffs between interspecific and intraspecific competitive performance was found, but this result was not consistent throughout the experiment. Two aspects of experimental design may tend to obscure genetically based tradeoffs across environments in many previously published experiments: (1) inability to isolate additive genetic from other sources of variation and (2) use of novel (e.g., laboratory) environments.

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