Heat stability studies at the ?-glycerophosphate dehydrogenase locus in populations of Drosophila melanogaster

1978 ◽  
Vol 16 (7-8) ◽  
pp. 769-775 ◽  
Author(s):  
Glenn C. Bewley
Genetics ◽  
1979 ◽  
Vol 91 (3) ◽  
pp. 521-535
Author(s):  
John A Kiger ◽  
Eric Golanty

ABSTRACT Two cyclic AMP phosphodiesterase enzymes (E.C.3.1.4.17) are present in homogenates of adult Drosophila melanogaster. The two enzymes differ from one another in heat stability, affinity for Mg++, Ca++ activation and molecular weight. They do not differ markedly in their affinities for cyclic AMP, and both exhibit anomalous Michaelis-Menten kinetics. The more heatlabile enzyme is controlled in a dosage-dependent manner by chromomere 3D4 of the X chromosome and is absent in flies that are deficient for chromomere 3D4. Chromomere 3D4 is also necessary for the maintenance of normal cAMP levels, for male fertility, and for normal female fertility and oogenesis. The structural gene(s) for the more heat-stable enzyme is located outside of chromomeres 3C12-3D4. Whether 3D4 contains a structural gene, or a regulatory gene necessary for the presence of the labile enzyme, remains to be determined.


Genetics ◽  
1988 ◽  
Vol 120 (3) ◽  
pp. 755-766
Author(s):  
M B Davis ◽  
R J MacIntyre

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.


Genetics ◽  
1983 ◽  
Vol 105 (2) ◽  
pp. 371-386
Author(s):  
Michael A Kotarski ◽  
Sally Pickert ◽  
Ross J MacIntyre

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.


Genetics ◽  
1972 ◽  
Vol 71 (1) ◽  
pp. 127-138
Author(s):  
Stephen J O'Brien ◽  
Ross J Macintyre

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.


Genetics ◽  
1983 ◽  
Vol 105 (1) ◽  
pp. 55-69
Author(s):  
Joseph J King ◽  
John F McDonald

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.


1979 ◽  
Vol 34 (3-4) ◽  
pp. 304-305 ◽  
Author(s):  
Michael M. Bentley ◽  
John H. Williamson

Abstract A new locus, Aldox-2, which affects the activity and heat stability of aldehyde oxidase in D. melanogaster is described. The Aldox-2 locus is localized to map position 86 on chromosome 2, between c and px. Aldehyde oxidase activity in Aldox-2 homozygotes is approximately 25 - 30% that of the Oregon-R wild-type control strain. The enzyme from the mutant stock is much more heat labile than is the enzyme from the wild-type strain. Both the activity and heat phenotypes are completely recessive.


1957 ◽  
Vol 190 (2) ◽  
pp. 303-309 ◽  
Author(s):  
Wayne M. Meyers ◽  
Kenneth L. Burdon

The incubation of guinea pig serum with a streptokinase-human plasminogen preparation (from purified plasminogen) activates a proteolytic enzyme in the guinea pig serum. Optimal conditions for activity, kinetics, Km values and heat stability of elements of this system were studied. The proteolytic activity of this system was strongly inhibited by lysine ethyl ester and p-toluenesulfonylarginine methyl ester, apparently in a competitive manner. Serum dilution activity curves suggest the presence in guinea pig serum of dissociable protease inhibitors. The proteolytic activity of human plasmin does not appear to be essential for the activation of guinea pig protease, as indicated by heat stability studies. Possible mechanisms of activation are discussed. A survey of other animal species showed the widespread presence of serum proteases which could be activated with streptokinase-human plasminogen mixtures. The human activator systems may prove to be a useful tool in experimental studies of the physiological significance of the protease system.


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