scholarly journals THE GENETICS OF DROSOPHILA SUBOBSCURA POPULATIONS. XIV. FURTHER DATA ON LINKAGE DISEQUILIBRIA

Genetics ◽  
1980 ◽  
Vol 95 (3) ◽  
pp. 757-768 ◽  
Author(s):  
M Loukas ◽  
C B Krimbas ◽  
K Morgan

ABSTRACT Data coming from one natural population of D. subobscura, that of Crete, are presented in detail and examined for nonrandom associations of genes and gene arrangements. This population and four others previously studied are reanalyzed for the detection of higher than first-order interactions. Only firstorder interactions are important and statistically significant, especially those concerning genes and inversions in which these genes are included. The paucity of linkage disequilibria detected is remarkable, and we argue that it does not depend on the methods of study, rather it is genuine. We further argue that most of the disequilibria detected are probably due to mechanisms based on epistatic selection.

Heredity ◽  
2002 ◽  
Vol 89 (2) ◽  
pp. 133-138 ◽  
Author(s):  
P Oliver ◽  
J A Castro ◽  
A Picornell ◽  
M M Ramon ◽  
E Solé ◽  
...  

Heredity ◽  
1980 ◽  
Vol 44 (2) ◽  
pp. 193-199 ◽  
Author(s):  
W D Atkinson ◽  
J A Miller

Genome ◽  
2005 ◽  
Vol 48 (6) ◽  
pp. 1010-1018 ◽  
Author(s):  
Pedro Oliver ◽  
Joan Balanyà ◽  
Maria Misericòrdia Ramon ◽  
Antònia Picornell ◽  
Lluis Serra ◽  
...  

The evolution of Drosophila subobscura mitochondrial DNA has been studied in experimental populations, founded with flies from a natural population from Calvià (Majorca, Balearic Islands, Spain). This population, like others founded in Europe, is characterized by the presence of 2 very common (>95%) mitochondrial haplotypes (named I and II) and rare and endemic haplotypes that appear at very low frequencies. Four experimental populations were established with flies having a heterogeneous nuclear genetic background, which was representative of the composition of the natural population. The populations were started with haplotypes I and II at an initial frequency of 50% each. After 33 generations, the 2 haplotypes coexisted. Random drift could be rejected as the only force responsible for the observed changes in haplotype frequencies. A slight but significant linear trend favouring a mtDNA (haploid) fitness effect has been detected, with a nonlinear deviation that could be due to a nuclear component. An analysis of chromosomal arrangements was made before the foundations of the cages and at generation 23. Our results indicated that the hypothesis that the maintenance of the frequencies of haplotypes I and II in natural populations could be due to their association with chromosomal arrangements remains controversial.Key words: natural selection, random drift, cytonuclear interactions, chromosomal arrangements, mtDNA haplotypes, Drosophila subobscura.


1978 ◽  
Vol 32 (3) ◽  
pp. 215-229 ◽  
Author(s):  
Charles H. Langley ◽  
Diana B. Smith ◽  
F. M. Johnson

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.


Genetics ◽  
1998 ◽  
Vol 149 (3) ◽  
pp. 1377-1382 ◽  
Author(s):  
José García-Martínez ◽  
José Aurelio Castro ◽  
Misericordia Ramón ◽  
Amparo Latorre ◽  
Andrés Moya

Abstract The evolution of Drosophila subobscura mitochondrial DNA has been studied in experimental populations, founded with flies from a natural population from Esporles (Majorca, Balearic Islands, Spain). This population, like other European ones, is characterized by the presence of two very common (>96%) mitochondrial haplotypes (called I and II) and rare and endemic haplotypes that appear at very low frequencies. There is no statistical evidence of positive Darwinian selection acting on the mitochondrial DNA variants according to Tajima's neutrality test. Two experimental populations, with one replicate each, were established with flies having a heterogeneous nuclear genetic background, which was representative of the composition of the natural population. Both populations were started with the two most frequent mitochondrial haplotypes, but at different initial frequencies. After 13 to 16 generations, haplotype II reached fixation in three cages and its frequency was 0.89 by generation 25 in the fourth cage. Random drift can be rejected as the force responsible for the observed changes in haplotype frequencies. There is not only statistical evidence of a linear trend favoring a mtDNA (haploid) fitness effect, but also of a significant nonlinear deviation that could be due to a nuclear component.


Genetics ◽  
1990 ◽  
Vol 126 (1) ◽  
pp. 121-129
Author(s):  
J N Macpherson ◽  
B S Weir ◽  
A J Leigh Brown

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.


Heredity ◽  
1999 ◽  
Vol 82 (1) ◽  
pp. 100-106 ◽  
Author(s):  
Dorcas Juana Orengo ◽  
Antonio Prevosti

Genome ◽  
2012 ◽  
Vol 55 (3) ◽  
pp. 214-221 ◽  
Author(s):  
Mihailo Jelić ◽  
José A. Castro ◽  
Zorana Kurbalija Novičić ◽  
Bojan Kenig ◽  
Danica Dimitrijević ◽  
...  

The genetic structure of Drosophila subobscura from the Balkan Peninsula was studied with respect to restriction site polymorphism of mitochondrial DNA in populations from the Derventa River Gorge and Sicevo Gorge (Serbia). To investigate the role of cytonuclear interactions in shaping mitochondrial DNA variability in natural populations of this species, the study was complemented with the analysis of linkage disequilibria between mitochondrial haplotypes and chromosomal inversion arrangements. Similar to other populations of D. subobscura, two main haplotypes (I and II) were found, as well as a series of less common ones. The frequencies of haplotypes I and II accounted for 25.8% and 71.0%, respectively, in the population from the Derventa River Gorge, and for 32.4% and 58.1%, respectively, in the population from Sicevo Gorge. One of the haplotypes harbored a large insertion (2.7 kb) in the A+T rich region. The frequency distribution of both haplotypes did not depart from neutrality. Contrary to prior studies, we did not detect any significant linkage disequilibrium between the two most frequent mtDNA haplotypes and any of the chromosomal arrangements in either of the populations. We conclude that linkage disequilibrium is not a general occurrence in natural populations of D. subobscura, and we discuss how transient coadaptations, ecologically specific selective pressures, and demographics could contribute to population-specific patterns of linkage disequilibrium.


Sign in / Sign up

Export Citation Format

Share Document