scholarly journals A STUDY OF LINKAGE DISEQUILIBRIUM IN POPULATIONS OF DROSOPHILA MELANOGASTER

Genetics ◽  
1973 ◽  
Vol 73 (2) ◽  
pp. 351-359
Author(s):  
Brian Charlesworth ◽  
Deborah Charlesworth
Keyword(s):  
Drosophila Melanogaster ◽  
Linkage Disequilibrium ◽  
Natural Population ◽  
Allele Frequencies ◽  
The Other ◽  
Protein Polymorphism ◽  
Chromosome 3 ◽  
Laboratory Population ◽  
Selective Control

ABSTRACT This paper presents the results of a study of linkage disequilibrium between five polymorphic enzyme genes located on chromosome 3 of D. melamgaster. Three sets of chromosomes were examined: two represented samples from successive years of the same natural population, and one came from a large laboratory population. Out of the thirty possible tests for linkage disequilibrium between pairs of loci, two were significant at the 5% level and two at the 1% level. This result cannot reasonably be ascribed to chance alone. The pairs of loci that had a significant correlation in one sample had higher than average correlations in the other samples (though not necessarily in the same direction); this effect was highly significant statistically. There was no tendency for the high correlations to be associated with tightness of linkage between the loci concerned. All five loci were involved in at least one significant effect. It was concluded that these results are difficult to explain on the neutral allele theory of protein polymorphism, but are consistent with the concept of selective control of allele frequencies.

scholarly journals LINKAGE DISEQUILIBRIUM IN NATURAL POPULATIONS OF DROSOPHILA MELANOGASTER. SEASONAL VARIATION

Genetics ◽  
1977 ◽  
Vol 86 (2) ◽  
pp. 447-454
Author(s):  
Charles H Langley ◽  
Kazuko Ito ◽  
Robert A Voelker
Keyword(s):  
Drosophila Melanogaster ◽  
Seasonal Variation ◽  
Linkage Disequilibrium ◽  
Natural Population ◽  
Natural Populations ◽  
The Other ◽  
Allozyme Loci

ABSTRACT Linkage disequilibrium among ten polymorphic allozyme loci and polymorphic inversions on chromosomes 2 and 3 in a natural population of Drosophila melanogaster was examined early and late in the annual season. Similar to previous studies, little linkage disequilibrium was observed among allozymes. The two significant cases that were observed in the first sample behaved in a contradictory way. One declined much more rapidly than expected due simply to recombination; the other declined slowly as expected. There was little change in allozyme or inversion frequencies during the season.

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.

scholarly journals Variation in the Direction of Selection Applied by Pentenol to the Alcohol Dehydrogenase Locus in Drosophila melanogaster

1977 ◽  
Vol 30 (3) ◽  
pp. 259 ◽  
Author(s):  
JG Oakeshott
Keyword(s):  
Drosophila Melanogaster ◽  
Alcohol Dehydrogenase ◽  
Null Allele ◽  
Developmental Time ◽  
The Other ◽  
Laboratory Population ◽  
Alcohol Dehydrogenases ◽  
Alcohol Dehydrogenase Activity ◽  
Active Alcohol ◽  
Selective Effects

This paper describes selective effects of pentenol-impregnated media on six genotypes at the alcohol dehydrogenase (Adh) locus in D. melanogaster. In the laboratory population studied, developmental times of pre-adults homozygous for an alcohol dehydrogenase 'null' allele increased with increasing pentenol concentrations. The developmental times of the other five genotypes, which produced active alcohol dehydrogenases, increased slightly at pentenol concentrations up to 0�0033%, but above this concentration they decreased markedly. In fact on 0�067% pentenol, the highest concentration tested, developmental times of these five genotypes were between 9 and 24 h less than their developmental times on media lacking penteno!. The magnitude of the reduction in developmental time differed significantly between genotypes and was positively correlated with alcohol dehydrogenase activity.

scholarly journals An Analysis of Polygenes Affecting Wing Shape on Chromosome 3 in Drosophila melanogaster

Genetics ◽  
1999 ◽  
Vol 153 (2) ◽  
pp. 773-786 ◽  
Author(s):  
Kenneth Weber ◽  
Robert Eisman ◽  
Lisa Morey ◽  
April Patty ◽  
Joshua Sparks ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Transposable Elements ◽  
Wing Shape ◽  
The Other ◽  
Chromosome 3 ◽  
Additive Effects ◽  
Data Set ◽  
The Third ◽  
Isogenic Lines ◽  
Negative Interactions

AbstractLoci on the third chromosome of Drosophila melanogaster that affect an index of wing shape were mapped, using recombinant isogenic lines, with transposable elements as markers. Many genes with small subequal effects are dispersed along the whole chromosome. Their alleles act nearly additively in heterozygotes. They have small correlated effects on leg shape, but no detectable effects on halteres. Small negative net interactions occur over most of the chromosome. The data set of 519 recombinant isogenic lines can be explained reasonably well by two models. One model posits an indefinitely large number of loci with no interactions. The other model posits 11 loci with additive effects whose sum equals the total phenotypic range and with large positive and negative interactions that nearly cancel each other.

scholarly journals Analysis of linkage disequilibria between allozyme loci in natural populations of Drosophila melanogaster

1978 ◽  
Vol 32 (3) ◽  
pp. 215-229 ◽  
Author(s):  
Charles H. Langley ◽  
Diana B. Smith ◽  
F. M. Johnson
Keyword(s):  
Drosophila Melanogaster ◽  
Linkage Disequilibrium ◽  
Natural Population ◽  
Analysis Of Variance ◽  
Natural Populations ◽  
Correlation Coefficients ◽  
Absolute Value ◽  
Linkage Disequilibria ◽  
Enzyme Loci ◽  
Allozyme Loci

SUMMARYLinkage disequilibria between pairs of 8 polymorphic enzyme loci (αGpdh, Mdh, Adh, Est-6, Pgm, Odh, Est-C and Acph) in some 100 natural population samples of Drosophila melanogaster were examined. The estimates of linkage disequilibrium were made from zygotic frequencies. The magnitude of linkage disequilibria are small and similar to those in previous reports. Variation in linkage disequilibrium among related subpopulations was analysed by analysis of variance of the correlation coefficients. Despite the small absolute value of linkage disequilibrium there is a suggestion of a correlation among related subpopulations. The magnitude of linkage disequilibrium was observed to be positively correlated with linkage. Two cage populations were observed to demonstrate large amounts of linkage disequilibrium between closely linked loci in contrast to the situation in natural populations. This is attributable to the finite sizes of these cage populations.

scholarly journals Extensive linkage disequilibrium in the achaete-scute complex of Drosophila melanogaster.

Genetics ◽  
1990 ◽  
Vol 126 (1) ◽  
pp. 121-129
Author(s):  
J N Macpherson ◽  
B S Weir ◽  
A J Leigh Brown
Keyword(s):  
Drosophila Melanogaster ◽  
Linkage Disequilibrium ◽  
Natural Population ◽  
Nucleotide Diversity ◽  
Single Site ◽  
Restriction Map ◽  
X Chromosomes ◽  
Linkage Disequilibria ◽  
Restriction Sites ◽  
Gametic Association

Abstract We have analyzed the level of gametic association between restriction map variants in a sample of 44 X chromosomes from a natural population of Drosophila melanogaster. Of 21 pairwise tests involving 7 restriction map polymorphisms in the yellow-achaete-scute complex, 17 were found to be significant, including some between restriction sites over 80 kb apart. Three-way linkage disequilibria and their variances were also estimated for all 35 three-way comparisons between these loci. Twelve such tests were found to be significant, again spanning distances of up to 80 kb on the restriction map. Only 9 of a possible 128 haplotypes were represented in the sample and 8 of these could be linked together by changes at a single site. The strength of these associations at y-ac-sc is unusual by comparison with studies on other regions of the genome of D. melanogaster, and is consistent with the very low level of recombination which has been reported for the complex. However, our estimate of nucleotide diversity in the region is not significantly different from those made for some other loci in this species.

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.

scholarly journals A CONTRIBUTION TO THE STUDY OF LINKAGE DISEQUILIBRIUM IN DROSOPHILA MELANOGASTER

1976 ◽  
Vol 18 (4) ◽  
pp. 739-745 ◽  
Author(s):  
S. Alahiotis ◽  
M. Pelecanos ◽  
A. Zacharopoulou
Keyword(s):  
Drosophila Melanogaster ◽  
Linkage Disequilibrium ◽  
Natural Population ◽  
Environmental Conditions ◽  
Gene Pool ◽  
Ecological Factors ◽  
Random Drift ◽  
Different Populations ◽  
Food Medium

Linkage disequilibrium was detected in 12 out of 30 cases involving gene alleles and inversions in three cage populations and in a natural population of Drosophila melanogaster from Greece. The cage populations possessed practically the same gene pool at their origin and were maintained simultaneously under the effects of the ecological factors "food medium" and "humidity". It is discussed that the correlation of the same direction found between the frequencies of nonallelic elements of Adh locus and In(2L)22D-34A or In(2R)52A-56F in such different populations as American, Japanese (Mukai et al., 1971, 1974; Langley et al., 1974) and Greek, as well as cage populations under different environmental conditions, could be attributed to the effect of epistatic selection. Moreover, it seems that the In(2L)22D-34A has a tendency to interact genetically with the α-Gpdh locus, particularly when the populations are maintained under crowding conditions. However, further data are needed to assess whether other cases of the observed nonrandom associations can be better explained as transient associations generated by random drift, or as the result of epistatic selection.

scholarly journals Molecular variation of Adh and P6 genes in an African population of Drosophila melanogaster and its relation to chromosomal inversions.

Genetics ◽  
1993 ◽  
Vol 134 (3) ◽  
pp. 789-799
Author(s):  
V Bénassi ◽  
S Aulard ◽  
S Mazeau ◽  
M Veuille
Keyword(s):  
Drosophila Melanogaster ◽  
Linkage Disequilibrium ◽  
Ivory Coast ◽  
The United States ◽  
The Other ◽  
African Population ◽  
Molecular Polymorphism ◽  
Chromosome Inversion ◽  
Or Gene ◽  
Chromosome Ii

Abstract Four-cutter molecular polymorphism of Adh and P6, and chromosome inversion polymorphism of chromosome II were investigated in 95 isogenic lines of an Ivory Coast population of Drosophila melanogaster, a species assumed to have recently spread throughout the world from a West African origin. The P6 gene showed little linkage disequilibrium with the In(2L)t inversion, although it is located within this inversion. This suggests that the inversion and the P6 locus have extensively exchanged genetic information through either double crossover or gene conversion. Allozymic variation in ADH was in linkage disequilibrium with In(2L)t and In(2R)NS inversions. Evidence suggests either that inversion linkage with the Fast allele is selectively maintained, or that this allele only recently appeared. Molecular polymorphism at the Adh locus in the Ivory Coast is not higher than in North American populations. New haplotypes specific to the African population were found, some of them connect the "WaS-like" haplotypes found at high frequencies in the United States to the other slow haplotypes. Their relation with In(2L)t supports the hypothesis that WaS recently recombined away from an In(2L)t chromosome which may be the cause of its divergence from the other haplotypes.

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