scholarly journals POST-TRANSLATIONAL MODIFICATION AS A POTENTIAL EXPLANATION OF HIGH LEVELS OF ENZYME POLYMORPHISM: XANTHINE DEHYDROGENASE AND ALDEHYDE OXIDASE IN DROSOPHILA MELANOGASTER

Genetics ◽  
1979 ◽  
Vol 91 (4) ◽  
pp. 695-722
Author(s):  
Victoria Finnerty ◽  
George Johnson
Keyword(s):  
Drosophila Melanogaster ◽  
Natural Populations ◽  
Aldehyde Oxidase ◽  
Xanthine Dehydrogenase ◽  
Enzyme Polymorphism ◽  
The Body ◽  
Post Translational Modification ◽  
Heritable Variation ◽  
Thermal Stabilities ◽  
Partial Restoration

ABSTRACT Xanthine dehydrogenase (XDH) and aldehyde oxidase (AO) in Drosophila melanogaster require for their activity the action of another unlinked locus, maroon-like (mal), While the XDH and A 0 loci are on chromosome 3, mal maps to the X chromosome. Although functional mal gene product is required for XDH and A 0 activity, it is possible to examine the effects of mutant mal alleles in those cases when pairs of mutants complement to produce a partial restoration of activity. To test whether mal mediates a post-translational modification of the XDH and A0 proteins, we constructed several mal heteroallelic complementing stocks of Drosophila in which the third chromosomes were co-isogenic. Since all lines were co-isogenic for the XDH and A0 structural genes, any variation in these enzymes seen when comparing these stocks must have been produced by post-translational modification by mal. We examined the XDH and A 0 proteins in these stocks by gel-sieving electrophoresis, a procedure that permits independent characterization of a protein's charge and shape, and is capable of discriminating many variants not detected in routine electrophoresis. In every mal heteroallelic combination, there is a significant alteration in protein shape, when compared to wild type. The magnitude of differences in shape of XDH and AO is correlated both with differences in their enzyme activities and with differences in their thermal stabilities. As the body of this variation appears heritable, any functional differences resulting from these variants are of real genetic and evolutionary interest. A similar post-translational modification of XDH and A0 by yet another locus, lxd, was subsequently documented in an analogous manner. The pattern of electrophoretic differences produced by mal and lxd modification is similar to that reported for electrophoretic "alleles" of XDH in natural populations. The implication is that heritable variation in electrophoretic mobility at these two enzyme loci, and potentially at other loci, is not necessarily allelic to the structural gene loci.

scholarly journals POST-TRANSLATIONAL MODIFICATION OF XANTHINE DEHYDROGENASE IN A NATURAL POPULATION OF DROSOPHILA MELANOGASTER

Genetics ◽  
1981 ◽  
Vol 98 (4) ◽  
pp. 817-831
Author(s):  
George Johnson ◽  
Victoria Finnerty ◽  
Daniel Hartl
Keyword(s):  
Drosophila Melanogaster ◽  
Natural Population ◽  
Aldehyde Oxidase ◽  
Xanthine Dehydrogenase ◽  
Chromosome 3 ◽  
Chromosome 2 ◽  
Structural Genes ◽  
Post Translational Modification ◽  
Polymorphic Loci

ABSTRACT Second chromosomes of D. melanogaster were isolated from a single natural population, and 40 were analyzed by gel-sieving electrophoresis for the presence of polymorphic loci on chromosome 2 that act to modify xanthine dehydrogenase and/or aldehyde oxidase, whose structural genes map to chromosome 3. Clear evidence of polymorphism for one or more xanthine dehydrogenase modifier loci was obtained.

An Ecological Study of the Alcohol Dehydrogenase (Adh) Polymorphism of Drosophila Melanogaster.

1980 ◽  
Vol 28 (6) ◽  
pp. 709 ◽  
Author(s):  
JA Mckenzie
Keyword(s):  
Drosophila Melanogaster ◽  
Ecological Study ◽  
Natural Populations ◽  
Random Processes ◽  
Enzyme Polymorphism ◽  
Quiescent State ◽  
Ecological Data ◽  
Gene Frequencies ◽  
Similar Gene ◽  
Selective Effects

Fluctuations in the numbers of adults of Drosophila melanogaster Mg. in the cellar of a vineyard in Victoria, Australia, were monitored for 5 years. Numbers fluctuated cyclically, from 50 at the end of winter to 100 000 immediately after harvest. Movement within the cellar system was restricted, especially in winter, leading to subpopulations being formed. Overwintering individuals were in a non-breeding quiescent state. These ecological conditions provide considerable potential for random processes. However, such effects did not seem of importance in the maintenance of the Adh polymorphism since concurrent samples in different areas of the cellar had similar gene frequencies, and similar genotypic distributions were observed from year to year in the cellar system as a whole. The relevance of ecological data in distinguishing between random and selective effects acting on enzyme polymorphism in natural populations is emphasised.

THE EFFECTS OF MOLYBATE, TUNGSTATE AND lxd ON ALDEHYDE OXIDASE AND XANTHINE DEHYDROGENASE IN DROSOPHILA MELANOGASTER

1981 ◽  
Vol 23 (4) ◽  
pp. 597-609 ◽  
Author(s):  
M. M. Bentley ◽  
J. H. Williamson ◽  
M. J. Oliver
Keyword(s):  
Drosophila Melanogaster ◽  
Sodium Tungstate ◽  
Enzyme System ◽  
Sodium Molybdate ◽  
Aldehyde Oxidase ◽  
Xanthine Dehydrogenase ◽  
Dietary Sodium ◽  
Screening Procedure ◽  
Eye Color

The effects of dietary sodium molybdate and sodium tungstate on eye color and aldehyde oxidase and xanthine dehydrogenase activities have been determined in Drosophila melanogaster. Dietary sodium tungstate administration has been used as a screening procedure to identify two new lxd alleles. Tungstate administration results in increased frequencies of "brown-eyed" flies in lxd stocks and a coordinate decrease in AO and XDH activities in all genotypes tested. The two new lxd alleles affect AO and XDH in a qualitatively but not quantitatively similar fashion to the original lxd allele. AO and XDH activity and AO-CRM levels appear much more sensitive to mutational perturbations of this gene-enzyme system than do XDH-CRM levels in the genotypes tested.

GENETIC CONTROL OF ALDEHYDE OXIDASE ACTIVITY AND CROSS-REACTING-MATERIAL IN DROSOPHILA MELANOGASTER

1978 ◽  
Vol 20 (4) ◽  
pp. 489-497 ◽  
Author(s):  
Eva M. Meidinger ◽  
John H. Williamson
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Control ◽  
Structural Gene ◽  
Oxidase Activity ◽  
Aldehyde Oxidase ◽  
Xanthine Dehydrogenase ◽  
The Other ◽  
Pyridoxal Oxidase

Four different genes are known to affect aldehyde oxidase activity (AO) in Drosophila melanogaster. Mutants at each of these loci eliminate AO activity and simultaneously eliminate detectable AO-crossing reacting material (AO-CRM) even though only one is the structural gene for AO (Aldoxn). The other three genes (cin1, lxd and mal) coordinately "control" the levels of activity of AO and two related enzymes, xanthine dehydrogenase (XDH) and pyridoxal oxidase (PO). Contrary to their effects on AO-CRM, neither of these three mutants eliminate XDH-CRM. A model of interaction of these enzymes and genes controlling their activities is discussed.

Expression of Drosophila melanogaster xanthine dehydrogenase in Aspergillus nidulans and some properties of the recombinant enzyme

2002 ◽  
Vol 362 (2) ◽  
pp. 223-229 ◽  
Author(s):  
Benjamin ADAMS ◽  
David J. LOWE ◽  
Andrew T. SMITH ◽  
Claudio SCAZZOCCHIO ◽  
Stephane DEMAIS ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Aspergillus Nidulans ◽  
Specific Activity ◽  
Recombinant Expression ◽  
Expression System ◽  
Complex Mixture ◽  
Xanthine Dehydrogenase ◽  
Cell System ◽  
Post Translational Modification ◽  
Enzyme Molecules

Recent crystal structures of xanthine dehydrogenase, xanthine oxidase and related enzymes have paved the way for a detailed structural and functional analysis of these enzymes. One problem encountered when working with these proteins, especially with recombinant protein, is that the preparations tend to be heterogeneous, with only a fraction of the enzyme molecules being active. This is due to the incompleteness of post-translational modification, which for this protein is a complex, and incompletely understood, process involving incorporation of the Mo and Fe/S centres. The enzyme has been expressed previously in both Drosophila and insect cells using baculovirus. The insect cell system has been exploited by Iwasaki et al. [Iwasaki, Okamoto, Nishino, Mizushima and Hori (2000) J. Biochem (Tokyo) 127, 771–778], but, for the rat enzyme, yields a complex mixture of enzyme forms, containing around 10% of functional enzyme. The expression of Drosophila melanogaster xanthine dehydrogenase in Aspergillus nidulans is described. The purified protein has been analysed both functionally and spectroscopically. Its specific activity is indistinguishable from that of the enzyme purified from fruit flies [Doyle, Burke, Chovnick, Dutton, Whittle and Bray (1996) Eur. J. Biochem. 239, 782–795], and it appears to be more active than recombinant xanthine dehydrogenase produced with the baculovirus system. EPR spectra of the recombinant Drosophila enzyme are reported, including parameters for the Fe/S centres. Only a very weak ‘Fe/SIII’ signal (g1,2,3, 2.057, 1.930, 1.858) was observed, in contrast to the strong analogous signal reported for the enzyme from baculovirus. Since this signal appears to be associated with incomplete post-translational modification, this is consistent with relatively more complete cofactor incorporation in the Aspergillus-produced enzyme. Thus we have developed a recombinant expression system for D. melanogaster xanthine dehydrogenase, which can be used for the production of site-specific mutations of this enzyme.

scholarly journals GENIC HETEROGENEITY WITHIN ELECTROPHORETIC "ALLELES" AND THE PATTERN OF VARIATION AMONG LOCI IN DROSOPHILA PSEUDOOBSCURA

Genetics ◽  
1979 ◽  
Vol 93 (4) ◽  
pp. 997-1018
Author(s):  
Rama S Singh
Keyword(s):  
Balancing Selection ◽  
Natural Populations ◽  
Aldehyde Oxidase ◽  
Xanthine Dehydrogenase ◽  
Drosophila Pseudoobscura ◽  
Mainland Population ◽  
Polymorphic Loci ◽  
Genic Variation ◽  
Pattern Of Variation

ABSTRACT An investigation, similar to our previously reported xanthine dehydrogenase study, was undertaken to examine the extent of hidden genic variation at nine loci (five larval proteins, three esterases and one aldehyde oxidase) by sequential application of various electrophoretic criteria employing pH, gel concentration and buffer variation. Polymorphic loci appear to fall into two distinct groups: weakly polymorphic, including larval protein 6, 7, 8, 10 and 13 and esterase-1 and -6; and highly polymorphic, including esterase-5, Xdh and possibly Ao. Monomorphic loci may belong to a third group different from all polymorphic lori. Bogota, a geographical isolate that is reproductively isolated from the mainland population, was found to be genetically distinct at four of the ten loci examined in detail so far, including Xdh, whereas previously it was found to be genetically distinct at none. These results are discussed in the light of balancing selection, neutral and mutation-selection hypotheses of genic variation in natural populations.

THE CONTROL OF ALDEHYDE OXIDASE AND XANTHINE DEHYDROGENASE ACTIVITIES AND CRM LEVELS BY THE mal LOCUS IN DROSOPHILA MELANOGASTER

1982 ◽  
Vol 24 (1) ◽  
pp. 11-17 ◽  
Author(s):  
M. M. Bentley ◽  
J. H. Williamson
Keyword(s):  
Drosophila Melanogaster ◽  
Full Advantage ◽  
Aldehyde Oxidase ◽  
Xanthine Dehydrogenase ◽  
Complementation Group ◽  
Activity Levels ◽  
Wild Type ◽  
Eye Color ◽  
Pleiotropic Phenotype

The effects of five new mal alleles on aldehyde oxidase (AO) and xanthine dehydrogenase (XDH) activities and CRM levels in Drosophila melanogaster are described. These alleles were isolated by taking full advantage of the pleiotropic phenotype exhibited by all previously described mal alleles and represent at least three unique examples of mal function. At least one of these alleles is a representative of a new complementation group. Two other alleles exhibit a wild-type eye color in homozygous stock and one of these is "leaky", exhibiting some 50% of the XDH activity normally found in Oregon-R control flies and some 12% of the AO activity. CRM and activity levels have been quantitated for both enzymes in all allelic heterozygotes. XDH-CRM levels vary only slightly around wild-type levels while AO-CRM levels appear much more sensitive to mutational alterations.

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