scholarly journals GENETIC ANALYSIS OF ASPARTATE AMINOTRANSFERASE ISOZYMES FROM HYBRIDS BETWEEN DROSOPHILA MELANOGASTER AND DROSOPHILA SIMULANS AND MUTAGEN-INDUCED ISOZYME VARIANTS

Genetics ◽  
1976 ◽  
Vol 83 (4) ◽  
pp. 753-764
Author(s):  
E H Grell
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Analysis ◽  
Genetic Map ◽  
Aspartate Aminotransferase ◽  
Electrophoretic Variants ◽  
F1 Hybrid ◽  
Naturally Occurring ◽  
Chromosome Arm ◽  
Ordinary Type ◽  
Low Activity

ABSTRACT The aspartate aminotransferases (designated GOT1 and GOT2) are two enzymes of Drosophila melanogaster for which naturally occurring electrophoretic variants were not found. There is an electrophoretic difference between D. melanogaster and D. simulans. Since the F1 hybrid offspring of these species are sterile, a genetic analysis of the ordinary type cannot be done on differences between the two species. A method was devised to make "partial hybrids" in which one chromosome arm is homozygous for melanogaster genes in an otherwise hybrid background. By using this method, Got1 was localized to 2R and Got2 to 2L. Once a gene can be assigned to a chromosome, it may be followed in crossing schemes and mutations from mutagen treatments may be looked for. At the locus of Got1 a mutation with low activity was recovered and designated Got1lo. It was located at a genetic map position of 75 on 2R. A Got2 mutant with a greater migration to the anode was recovered and designated Got2J. It was located at a genetic map position of 3.0, and in the salivary chromosome was between 22B1 and 22B4 inclusive.

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.

scholarly journals Direct measurement of in vivo flux differences between electrophoretic variants of G6PD from Drosophila melanogaster.

Genetics ◽  
1992 ◽  
Vol 132 (3) ◽  
pp. 783-787
Author(s):  
J Labate ◽  
W F Eanes
Keyword(s):  
Drosophila Melanogaster ◽  
Steady State ◽  
Adaptive Significance ◽  
Electrophoretic Variants ◽  
Naturally Occurring ◽  
Steady State Kinetics ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
In Vivo Flux ◽  
Pathway Flux

Abstract Demonstrating that naturally occurring enzyme polymorphisms significantly impact metabolic pathway flux is a fundamental step in examining the possible adaptive significance of such polymorphisms. In earlier studies of the glucose-6-phosphate dehydrogenase (G6PD) polymorphism in Drosophila melanogaster, we used two different methods, exploiting both genotype-dependent interactions with the 6Pgd locus, and conventional steady-state kinetics to examine activity differences between the two common allozymes. In this report we use 1-14C- and 6-14C-labeled glucose to estimate directly genotype-dependent flux differences through the pentose shunt. Our results show that G6pdA genotype possesses statistically lower pentose shunt flux than G6pdB at 25 degrees. We estimate this to be about a 32% reduction, which is consistent with the two former studies. These results reflect a significant responsiveness of pentose shunt flux to activity variation at the G6PD-catalyzed step, and predict that the G6PD allozymes generate a polymorphism for pentose shunt flux.

scholarly journals A GENETIC ANALYSIS OF THE KILLER-PRUNE (K-pn) LOCUS OF DROSOPHILA MELANOGASTER

Genetics ◽  
1969 ◽  
Vol 62 (2) ◽  
pp. 353-358
Author(s):  
Eliezer Lifschytz ◽  
Raphael Falk
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Analysis

scholarly journals ORIENTATION DISRUPTOR (ord): A RECOMBINATION-DEFECTIVE AND DISJUNCTION-DEFECTIVE MEIOTIC MUTANT IN DROSOPHILA MELANOGASTER

Genetics ◽  
1976 ◽  
Vol 84 (3) ◽  
pp. 545-572
Author(s):  
James M Mason
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Map ◽  
Crossing Over ◽  
Prophase I ◽  
Sister Chromatids

ABSTRACT The effects of a semidominant autosomal meiotic mutant, orientation disruptor (symbol: ord), located at 2-103.5 on the genetic map and in region 59B-D of the salivary map, have been examined genetically and cytologically. The results are as follows. (1) Crossing over in homozygous females is reduced to about seven percent of controls on all chromosomes, with the reduction greatest in distal regions. (2) Crossing over on different chromosomes is independent. (3) Reductional nondisjunction of any given chromosome is increased to about thirty percent of gametes from homozygous females. The probability of such nondisjunction is the same among exchange and nonexchange tetrads with the exception that a very proximal exchange tends to regularize segregation. (4) Equational nondisjunction of each chromosome is increased to about ten percent of gametes in homozygous females; this nondisjunction is independent of exchange. (5) The distributive pairing system is operative in homozygous females. (6) In homozygous males, reductional nondisjunction of each chromosome is increased to about ten percent, and equational nondisjunction to about twenty percent, of all gametes. (7) Cytologically, two distinct meiotic divisions occur in spermatocytes of homozygous males. The first division looks normal although occasional univalents are present at prophase I and a few lagging chromosomes are seen at anaphase I. However, sister chromatids of most chromosomes have precociously separated by metaphase II. Possible functions of the ord+ gene are considered.

scholarly journals THIRD-CHROMOSOME MUTAGEN-SENSITIVE MUTANTS OF DROSOPHILA MELANOGASTER

Genetics ◽  
1981 ◽  
Vol 97 (3-4) ◽  
pp. 607-623 ◽  
Author(s):  
J B Boyd ◽  
M D Golino ◽  
K E S Shaw ◽  
C J Osgood ◽  
M M Green
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Map ◽  
Nitrogen Mustard ◽  
Chromosome 3 ◽  
Methyl Methanesulfonate ◽  
Dna Metabolism ◽  
Genetic Analyses ◽  
Chemical Mutagens ◽  
Complementation Groups ◽  
Biochemical Analyses

ABSTRACT A total of 34 third chromosomes of Drosophila melanogaster that render homozygous larvae hypersensitive to killing by chemical mutagens have been isolated. Genetic analyses have placed responsible mutations in more than eleven complementation groups. Mutants in three complementation groups are strongly sensitive to methyl methanesulfonate, those in one are sensitive to nitrogen mustard, and mutants in six groups are hypersensitive to both mutagens. Eight of the ten loci mapped fall within 15% of the genetic map that encompasses the centromere of chromosome 3. Mutants from four of the complementation groups are associated with moderate to strong meiotic effects in females. Preliminary biochemical analyses have implicated seven of these loci in DNA metabolism.

scholarly journals Genetics of Differences in Pheromonal Hydrocarbons Between Drosophila melanogaster and D. simulans

Genetics ◽  
1996 ◽  
Vol 143 (1) ◽  
pp. 353-364 ◽  
Author(s):  
Jerry A Coyne
Keyword(s):  
Drosophila Melanogaster ◽  
Sexual Dimorphism ◽  
Genetic Analysis ◽  
Species Difference ◽  
The Other ◽  
Chromosome 3 ◽  
Apparent Effect ◽  
The Third ◽  
Hydrocarbon Profile ◽  
The Right

Abstract Females of Drosophila melanogaster and its sibling species D. simulans have very different cuticular hydrocarbons, with the former bearing predominantly 7,11-heptacosadiene and the latter 7-tricosene. This difference contributes to reproductive isolation between the species. Genetic analysis shows that this difference maps to only the third chromosome, with the other three chromosomes having no apparent effect. The D. simulans alleles on the left arm of chromosome 3 are largely recessive, allowing us to search for the relevant regions using D. melanogaster deficiencies. At least four nonoverlapping regions of this arm have large effects on the hydrocarbon profile, implying that several genes on this arm are responsible for the species difference. Because the right arm of chromosome 3 also affects the hydrocarbon profile, a minimum of five genes appear to be involved. The large effect of the third chromosome on hydrocarbons has also been reported in the hybridization between D. simulans and its closer relative D. sechellia, implying either an evolutionaly convergence or the retention in D. sechllia of an ancestral sexual dimorphism.

A Novel System of Fertility Rescue in Drosophila Hybrids Reveals a Link Between Hybrid Lethality and Female Sterility

Genetics ◽  
2003 ◽  
Vol 163 (1) ◽  
pp. 217-226 ◽  
Author(s):  
Daniel A Barbash ◽  
Michael Ashburner
Keyword(s):  
Drosophila Melanogaster ◽  
Low Temperature ◽  
Genetic Basis ◽  
Female Sterility ◽  
Hybrid Lethality ◽  
Hybrid Male ◽  
Hybrid Female ◽  
F1 Hybrid ◽  
Drosophila Gene

Abstract Hybrid daughters of crosses between Drosophila melanogaster females and males from the D. simulans species clade are fully viable at low temperature but have agametic ovaries and are thus sterile. We report here that mutations in the D. melanogaster gene Hybrid male rescue (Hmr), along with unidentified polymorphic factors, rescue this agametic phenotype in both D. melanogaster/D. simulans and D. melanogaster/D. mauritiana F1 female hybrids. These hybrids produced small numbers of progeny in backcrosses, their low fecundity being caused by incomplete rescue of oogenesis as well as by zygotic lethality. F1 hybrid males from these crosses remained fully sterile. Hmr+ is the first Drosophila gene shown to cause hybrid female sterility. These results also suggest that, while there is some common genetic basis to hybrid lethality and female sterility in D. melanogaster, hybrid females are more sensitive to fertility defects than to lethality.

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