scholarly journals The α-Glycerophosphate Cycle in Drosophila melanogaster. III. Relative Viability of "Null" Mutants at the α-Glycerophosphate Dehydrogenase-1 Locus

1972 ◽  
Vol 106 (952) ◽  
pp. 767-771 ◽  
Author(s):  
Stephen J. O'Brien ◽  
Bruce Wallace ◽  
Ross J. MacIntyre
Keyword(s):  
Drosophila Melanogaster ◽  
Glycerophosphate Dehydrogenase ◽  
Relative Viability ◽  
Null Mutants

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.

A genetic analysis of the alpha-glycerophosphate oxidase locus in Drosophila melanogaster.

Genetics ◽  
1988 ◽  
Vol 120 (3) ◽  
pp. 755-766
Author(s):  
M B Davis ◽  
R J MacIntyre
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Analysis ◽  
Structural Gene ◽  
Mitochondrial Enzyme ◽  
Synthetic Lethal ◽  
Lethal Phenotype ◽  
Cytoplasmic Enzyme ◽  
Glycerophosphate Dehydrogenase ◽  
Null Mutants

Abstract The gene for alpha-glycerophosphate oxidase, the nuclear encoded mitochondrial enzyme of the alpha-glycerophosphate cycle (alpha GP); has been mapped in Drosophila melanogaster. Several interstitial deficiencies in region 50c-53AB of chromosome 2R were used to localize the structural gene to 52D2-5. In addition, mutations of alpha GPO were generated; alpha GPO mutants are viable yet flightless. Interactions of alpha GPO with alpha-glycerophosphate dehydrogenase (alpha GPDH), the cytoplasmic enzyme of the alpha GP cycle, were investigated through the synthesis of a series of alpha GPDHnull-alpha GPOnull double mutants. Of the six double null mutants constructed, four alpha GPDH-alpha GPO double nulls are viable and flightless. Two double mutants, however, exhibit an allelic-dependent synthetic lethal phenotype.

A CYTOGENETIC ANALYSIS OF THE CHROMOSOMAL REGION SURROUNDING THE α-GLYCEROPHOSPHATE DEHYDROGENASE LOCUS OF DROSOPHILA MELANOGASTER

Genetics ◽  
1983 ◽  
Vol 105 (2) ◽  
pp. 371-386
Author(s):  
Michael A Kotarski ◽  
Sally Pickert ◽  
Ross J MacIntyre
Keyword(s):  
Drosophila Melanogaster ◽  
Polytene Chromosome ◽  
Cytogenetic Analysis ◽  
Chromosomal Region ◽  
Chromosome Band ◽  
Recombination Analysis ◽  
Chromosome 2 ◽  
Recessive Lethal ◽  
Lethal Mutations ◽  
Glycerophosphate Dehydrogenase

ABSTRACT The chromosomal region surrounding the structural gene for α-glycerophosphate dehydrogenase (αGpdh, 2-20.5) of Drosophila melanogaster has been studied in detail. Forty-three EMS-induced recessive lethal mutations and five previously identified visible mutations have been localized within the 25A-27D region of chromosome 2 by deficiency mapping and in some cases by a recombination analysis. The 43 lethal mutations specify 17 lethal loci. ?Gpdh has been localized to a single polytene chromosome band, 25F5, and there apparently are no lethals that map to the αGpdh locus.

scholarly journals Drosophila melanogaster Scramblases modulate synaptic transmission

2006 ◽  
Vol 173 (1) ◽  
pp. 69-82 ◽  
Author(s):  
Usha Acharya ◽  
Michael Beth Edwards ◽  
Ramon A. Jorquera ◽  
Hugo Silva ◽  
Kunio Nagashima ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Plasma Membrane ◽  
Membrane Proteins ◽  
Synaptic Transmission ◽  
Blood Cells ◽  
Neuromuscular Synapses ◽  
Neurotransmitter Secretion ◽  
Reserve Pool ◽  
Null Mutants

Scramblases are a family of single-pass plasma membrane proteins, identified by their purported ability to scramble phospholipids across the two layers of plasma membrane isolated from platelets and red blood cells. However, their true in vivo role has yet to be elucidated. We report the generation and isolation of null mutants of two Scramblases identified in Drosophila melanogaster. We demonstrate that flies lacking either or both of these Scramblases are not compromised in vivo in processes requiring scrambling of phospholipids. Instead, we show that D. melanogaster lacking both Scramblases have more vesicles and display enhanced recruitment from a reserve pool of vesicles and increased neurotransmitter secretion at the larval neuromuscular synapses. These defects are corrected by the introduction of a genomic copy of the Scramb 1 gene. The lack of phenotypes related to failure of scrambling and the neurophysiological analysis lead us to propose that Scramblases play a modulatory role in the process of neurotransmission.

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).

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.

GENETIC LOCALIZATION AND BIOCHEMICAL CHARACTERIZATION OF A TRANS-ACTING REGULATORY EFFECT IN DROSOPHILA

Genetics ◽  
1983 ◽  
Vol 105 (1) ◽  
pp. 55-69
Author(s):  
Joseph J King ◽  
John F McDonald
Keyword(s):  
Drosophila Melanogaster ◽  
Biochemical Characterization ◽  
Regulatory Gene ◽  
Regulatory Effect ◽  
Protein Levels ◽  
The Third ◽  
Genetic Localization ◽  
Glycerophosphate Dehydrogenase

ABSTRACT A region-specific, trans-acting regulatory gene that alters in vivo protein levels of α-glycerophosphate dehydrogenase (α-GPDH) has been mapped to position 55.4 on the third chromosome of Drosophila melanogaster. The gene has been found to affect the in vivo stability of α-GPDH in adult thoracic tissue but has no effect on α-GPDH levels in the abdomen. Although no other thoracic proteins were found to be influenced by the locus, it appears to modify the level of one additional abdominal protein. The action of the gene over development and its possible mode of control are discussed.

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