Experimental Measurement of the Relative Viability of the Mutant Ebony11in Drosophila melanogaster

1952 ◽  
Vol 86 (826) ◽  
pp. 45-48 ◽  
Author(s):  
Ray Moree
Keyword(s):  
Drosophila Melanogaster ◽  
Experimental Measurement ◽  
Relative Viability

scholarly journals LETHAL EFFECTS OF LOW AND "NULL" ACTIVITY ALLELES OF 6-PHOSPHOGLUCONATE DEHYDROGENASE IN DROSOPHILA MELANOGASTER

Genetics ◽  
1975 ◽  
Vol 79 (3) ◽  
pp. 451-457
Author(s):  
Glenn C Bewley ◽  
John C Lucchesi
Keyword(s):  
Drosophila Melanogaster ◽  
Embryonic Development ◽  
Enzymatic Activity ◽  
Null Allele ◽  
Developmental Rate ◽  
Lethal Effects ◽  
Homozygous Condition ◽  
Phosphogluconate Dehydrogenase ◽  
Relative Viability ◽  
Low Activity

ABSTRACT EMS-induced "null" and low activity alleles for 6-phosphogluconate dehydrogenase were characterized with respect to enzymatic activity, relative viability, fertility, and the effective lethal phase. It was determined that flies hemizygous and homozygous for the low activity allele, Pgd  -, possessed a depressed developmental rate, diminished viability, and loss of female fertility. Heterozygotes for Pgd  - and a deficiency for Pgd  + were lethal. The "null" activity allele demonstrated a lethal phenotype in both the hemizygous and homozygous condition. The effective lethal phase for the "null" allele occurs during late embryonic development (20-22 hr).

scholarly journals THE α-GLYCEROPHOSPHATE IN DROSOPHILA MELANOGASTER II. GENETIC ASPECTS

Genetics ◽  
1972 ◽  
Vol 71 (1) ◽  
pp. 127-138
Author(s):  
Stephen J O'Brien ◽  
Ross J Macintyre
Keyword(s):  
Drosophila Melanogaster ◽  
Energy Production ◽  
Null Alleles ◽  
Electrophoretic Variant ◽  
Electrophoretic Variants ◽  
Glycerophosphate Dehydrogenase ◽  
Naturally Occurring ◽  
Relative Viability ◽  
Null Mutants ◽  
Independent Mutant

ABSTRACT Seven alleles of the α-Glycerophosphate dehydrogenase-1 (αGpdh-1) locus of Drosophila melanogaster have been described. These include two naturally occurring electrophoretic variants, one EMS-induced electrophoretic variant, and four EMS-induced "null" or "zero" mutants. With the electrophoretic variants, the locus was mapped to II-20.5 ± 2.5. A complementation matrix was prepared utilizing the null mutants. Three of the four mutants and a deletion of the locus (Grell 1967) exhibit dosage dependency. The dosage independent mutant exhibits complementation with two of the other null alleles. Flies genetically deficient in α-glycerophosphate dehydrogenase are fertile, but their relative viability is severely diminished. Such flies also lose the ability to sustain flight, an observation consistent with the enzyme's function in energy production. The levels of mitochondrial α-glycerophosphate oxidase, measured in flies genetically deficient in the cytoplasmic enzyme, were normal.

THE GENETIC STRUCTURE OF NATURAL POPULATIONS OF DROSOPHILA MELANOGASTER. XV. NATURE OF DEVELOPMENTAL HOMEOSTASIS FOR VIABILITY

Genetics ◽  
1982 ◽  
Vol 101 (2) ◽  
pp. 279-300
Author(s):  
Terumi Mukai ◽  
Sadao I Chigusa ◽  
Shin-Ichi Kusakabe
Keyword(s):  
Drosophila Melanogaster ◽  
Natural Populations ◽  
Error Variance ◽  
Sampling Variance ◽  
Environmental Variance ◽  
Developmental Homeostasis ◽  
Relative Viability ◽  
The Difference ◽  
Two Populations ◽  
New Mutations

ABSTRACT Developmental homeostasis of relative viability was examined for homozygotes and heterozygotes using second chromosomes from two populations of Drosophila melanogaster. One was a chromosome population in which spontaneous mutations were allowed to accumulate since it was begun with a single near-normal second chromosome. The second was a natural population approximately at equilibrium. For the estimation of relative viability, the Cy method was employed (Wallace 1956), and environmental variance between simultaneously replicated cultures was used as the index of developmental homeostasis. A new method was used in the estimation of sampling variance for relative viability that was employed for the calculation of environmental variance (error variance between simultaneously replicated cultures — sampling variance). The following findings were obtained.: (1) The difference in environmental variance between homozygotes and heterozygotes could not be seen when a chromosome population with variation due to new mutations was tested. (2) When a chromosome group isolated from an approximate equilibrium population was examined, heterozygotes manifested a smaller environmental variance than the homozygotes if their relative viabilities were approximately the same. (3) There was a slight negative correlation between viability and environmental variance, although opposite results were found when the viabilities of individuals were high, especially when overdominance (coupling overdominance, Mukai 1969 a, b) was manifest. On the basis of these findings, it was concluded that developmental homeostasis was a product of natural selection, and its mechanism was discussed.

scholarly journals THE α-GLYCEROPHOSPHATE CYCLE IN DROSOPHILA MELANOGASTER

1974 ◽  
Vol 63 (3) ◽  
pp. 864-882 ◽  
Author(s):  
Stephen J. O'Brien ◽  
Yoshio Shimada
Keyword(s):  
Drosophila Melanogaster ◽  
Oxidative Phosphorylation ◽  
Adult Life ◽  
Respiratory Control ◽  
Premature Mortality ◽  
Pyridine Nucleotide ◽  
Null Alleles ◽  
Wild Type ◽  
Relative Viability ◽  
In The Wild

"Null" mutations previously isolated at the αGpdh-1 locus of Drosophila melanogaster, because of disruption of the energy-producing α-glycerophosphate cycle, severely restrict the flight ability and relative viability of affected individuals. Two "null" alleles, αGpdh-1BO-1-4, and αGpdh-1BO-1-5, when made hemizygous with a deficiency of the αGpdh-1 locus, Df(2L)GdhA, were rendered homozygous by recombination with and selective elimination of the Df(2L)GdhA chromosome. After over 25 generations, a homozygous αGpdh-1BO-1-4 stock regained the ability to fly despite the continued absence of measurable αGPDH activity. Inter se heterozygotes of three noncomplementing αGpdh-1 "null" alleles and the "adapted" αGpdh-1BO-1-4 homozygotes were examined for metabolic enzymatic activities related to the energy-producing and pyridine nucleotide-regulating functions of the α-glycerophosphate cycle in Drosophila. The enzyme functions tested included glyceraldehyde-3-phosphate dehydrogenase, cytoplasmic and soluble malate dehydrogenase, lactate dehydrogenase, mitochondrial NADH oxidation, oxidative phosphorylation, and respiratory control with the substrates α-glycerophosphate, succinate, and pyruvate. These activities in any of the mutant genotypes in early adult life were indistinguishable from those in the wild type. There was, however, a premature deterioration and atrophy of the ultrastructural integrity of flight muscle sarcosomes observed by electron microscopy in the "null" mutants. These observations were correlated with a decrease in state 3 mitochondrial oxidation with α-glycerophosphate, succinate, and pyruvate, as well as with loss of respiratory control in adults as early as 2 wk after eclosion. Such observations, which normally are seen in aged dipterans, were accompanied by premature mortality of the mutant heterozygotes. The adapted αGpdh-1BO-1-4 was identical with wild type in each of the aging characters with the single exception of lowered rates of mitochondrial oxidative phosphorylation.

scholarly journals The mutational rate of Drosophila viability decline: tinkering with old data

2002 ◽  
Vol 80 (2) ◽  
pp. 99-105 ◽  
Author(s):  
A. GARCÍA-DORADO ◽  
A. CABALLERO
Keyword(s):  
Drosophila Melanogaster ◽  
Linear Term ◽  
Term Experiment ◽  
Relative Viability ◽  
Long Term Experiment ◽  
Forced Regression ◽  
Chromosome Ii ◽  
Classical Mutation ◽  
Linear Decay

In the first 25 generations of his classical mutation accumulation experiment, T. Mukai estimated a large rate of early linear decay for the relative viability of Drosophila melanogaster chromosome II (ΔMII = 0.004). Mukai forced through zero the regression of viability decline on generation number, but it has recently been shown (Fry, 2001) that a similar decline (ΔMII = 0.006) is obtained from unforced regression even if generation 32 instead of generation 25 (whose validity has been questioned) is included. We show that, from the perspective of the whole long-term experiment, it is hard to decide up to which generation viability can be considered to decline linearly. Depending on this decision, and on whether or not the regression is forced through the origin, very different estimates are obtained. Furthermore, the particular behaviour of the lines used as control suggests that they could have been different from the remaining lines at the beginning of the experiment, and casts doubts on the adequacy of a forced regression. Estimates from the linear unforced regression (ΔMII = 0.011) or from the linear term in a quadratic unforced regression (ΔMII = 0.001) are very different. The data fit both models very well, and the choice between them should be based on biological grounds.

scholarly journals ESTIMATION OF FITNESS COMPONENTS IN DROSOPHILA MELANOGASTER. II. INFLUENCE OF REDUCED TRANSMISSION FREQUENCY

Genetics ◽  
1979 ◽  
Vol 91 (2) ◽  
pp. 359-368
Author(s):  
Alan J Katz
Keyword(s):  
Drosophila Melanogaster ◽  
Wild Type ◽  
Fitness Components ◽  
Transmission Frequency ◽  
Reciprocal Crosses ◽  
Relative Viability ◽  
Mendelian Expectation

ABSTRACT Results are presented of further analyses of the significant effects of reciprocal crosses reported by KATZ and CARDELLINO(1978) in regard to viability indices of wild-type second chromosome heterozygotes. The observed differences between reciprocal crosses can be explained by the existence of reduced transmission frequencies of the wild-type homologue from Pm/+ and Cy/+ paternal parents. Mean estimates of transmission frequencies from Pm/+ and cy/+ males in California and Japan populations are significantly less than the Mendelian expectation of 1/2. The transmission frequencies of +i chromosomes from Pm/+i and Cy/+i males are also found to be positively correlated in the California and pooled populations, suggesting that the degree of distortion is primarily due to the +i chromosome rather than to Cy or Pm. A sufficient estimator of relative viability that is independent of distorted transmission frequencies is derived for use in the Cy/Pm technique of viability estimation.

scholarly journals ESTIMATION OF FITNESS COMPONENTS IN DROSOPHILA MELANOGASTER. I. HETEROZYGOTE VIABILITY INDICES

Genetics ◽  
1978 ◽  
Vol 88 (1) ◽  
pp. 139-148
Author(s):  
Alan J Katz ◽  
Ricardo A Cardellino
Keyword(s):  
Drosophila Melanogaster ◽  
Natural Populations ◽  
Reciprocal Effects ◽  
Wild Type ◽  
Genotypic Variance ◽  
Fitness Components ◽  
Marker Chromosomes ◽  
The Future ◽  
Relative Viability

ABSTRACT We examine the assumption of "dominance" with regard to viability of the Cy and Pm marker chromosomes in D. melanogaster. This assumption is often invoked for the extraction of wild-type second chromosomes from natural populations and for the calculation of relative viability indices. Significant genotypic variances for viability are found among both C y / f i and P m / f i heterozygotes in California and Japanese populations. The magnitude of the Pm/+i genotypic variance is substantially less than that of the Cy/+j heterozygotes (less than one half). Significant reciprocal effects are also found to influence Cy/+j, Pm/+i and + J f j viabilities. We conclude that viability indices of heterozygotes based on the Curly method are biased. We suggest that viability indices in the future be expressed relative to the viability of the Cy/Pm genotype (Curly-Plum method) or possibly that of the Pm/+i genotype (Plum method).

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