A Comprehensive Study of Genic Variation in Natural Populations of Drosophila melanogaster. III. Variations in Genetic Structure and Their Causes Between Drosophila melanogaster and Its Sibling Species Drosophila simulans

Genetics ◽  
1987 ◽  
Vol 117 (4) ◽  
pp. 697-710
Author(s):  
M Choudhary ◽  
Rama S Singh
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Structure ◽  
Natural Populations ◽  
Drosophila Simulans ◽  
Geographic Differentiation ◽  
Dna Variation ◽  
Genic Variation ◽  
Pattern Of Variation ◽  
Physiological Characters ◽  
Comprehensive Study

ABSTRACT The natural populations of Drosophila melanogaster and Drosophila simulans were compared for their genetic structure. A total of 114 gene-protein loci were studied in four mainland (from Europe and Africa) and an island (Seychelle) populations of D. simulans and the results were compared with those obtained on the same set of homologous loci in fifteen worldwide populations of D. melanogaster. The main results are as follows: (1) D. melanogaster shows a significantly higher proportion of loci polymorphic than D. simulans (52% vs. 39%, P < 0.05), (2) both species have similar mean heterozygosity and mean number of alleles per locus, (3) the two species share some highly polymorphic loci but they do not share loci that show high geographic differentiation, and (4) D. simulans shows significantly less geographic differentiation than D. melanogaster. The differences in genetic differentiation between the two species are limited to loci located on the X and second chromosomes only; loci on the third chromosome show similar level of geographic differentiation in both species. These two species have previously been shown to differ in their pattern of variation for chromosomal polymorphisms, quantitative and physiological characters, two-dimensional electrophoretic (2DE) proteins, middle repetitive DNA and mitochondrial DNA. Variation in niche-widths and/or genetic "strategies" of adaptation appear to be the main causes of differences in the genetic structure of these two species.

scholarly journals A comprehensive study of genic variation in natural populations of Drosophila melanogaster. VI. Patterns and processes of genic divergence between D. melanogaster and its sibling species, Drosophila simulans.

Genetics ◽  
1992 ◽  
Vol 130 (4) ◽  
pp. 843-853
Author(s):  
M Choudhary ◽  
M B Coulthart ◽  
R S Singh
Keyword(s):  
Drosophila Melanogaster ◽  
Sibling Species ◽  
Natural Populations ◽  
Drosophila Simulans ◽  
Significant Heterogeneity ◽  
Homologous Proteins ◽  
Two Dimensional Gel Electrophoresis ◽  
Protein Coding ◽  
Genic Variation ◽  
Patterns And Processes

Abstract We present here an extensive set of data on allelic differences between homologous proteins of Drosophila melanogaster and its sibling species, Drosophila simulans, obtained by nondenaturing one-dimensional, and denaturing two-dimensional gel electrophoresis. The data suggest that, for these two species, (1) approximately 10% of protein-coding loci have no alleles in common in our sample, (2) the extent of genic variation at a locus (mean heterozygosity) within a species is not correlated with the extent of divergence (Nei's genetic distance) at that locus between species, and (3) significant heterogeneity of divergence rates exists for different structural/functional classes of loci. These results are discussed in the context of the dynamics of genetic variation within and between species.

scholarly journals Tirant stealthily invaded natural Drosophila melanogaster populations during the last century

2020 ◽  
Author(s):  
Florian Schwarz ◽  
Filip Wierzbicki ◽  
Kirsten-André Senti ◽  
Robert Kofler
Keyword(s):  
Drosophila Melanogaster ◽  
Insertion Site ◽  
Natural Populations ◽  
P Element ◽  
Past Century ◽  
Time Points ◽  
The Past ◽  
Living Fossils ◽  
Late Discovery ◽  
Comprehensive Study

AbstractIt was long thought that solely three different transposable elements - the I-element, the P-element and hobo - invaded natural D. melanogaster populations within the last century. By sequencing the ‘living fossils’ of Drosophila research, i.e. D. melanogaster strains sampled from natural populations at different time points, we show that a fourth TE, Tirant, invaded D. melanogaster populations during the past century. Tirant likely spread in D. melanogaster populations around 1938, followed by the I-element, hobo, and, lastly, the P-element. In addition to the recent insertions of the canonical Tirant, D. melanogaster strains harbour degraded Tirant sequences in the heterochromatin which are likely due to an ancient invasion, possibly predating the split of D. melanogaster and D. simulans. In contrast to the I-element, P-element and hobo, we did not find that Tirant induces any hybrid dysgenesis symptoms. This absence of apparent phenotypic effects may explain the late discovery of the Tirant invasion. Recent Tirant insertions were found in all investigated natural populations. Populations from Tasmania carry distinct Tirant sequences, likely due to a founder effect. By investigating the TE composition of natural populations and strains sampled at different time points, insertion site polymorphisms, piRNAs and phenotypic effects, we provide a comprehensive study of a natural TE invasion.

A Comprehensive Study of Genic Variation in Natural Populations of Drosophila melanogaster. I. Estimates of Gene Flow from Rare Alleles

Genetics ◽  
1987 ◽  
Vol 115 (2) ◽  
pp. 313-322
Author(s):  
Rama S Singh ◽  
Lorenz R Rhomberg
Keyword(s):  
Drosophila Melanogaster ◽  
Gene Flow ◽  
West Coast ◽  
Natural Populations ◽  
Evolutionary Significance ◽  
Study Program ◽  
Asian Populations ◽  
Rare Alleles ◽  
Geographic Populations ◽  
Genic Variation

ABSTRACT In order to assess the evolutionary significance of molecular variation in natural populations of Drosophila melanogaster, we have started a comprehensive genetic variation study program employing a relatively large number of gene-protein loci and an array of populations obtained from various geographic locations throughout the world. In this first report we provide estimates of gene flow based on the spatial distributions of rare alleles at 117 gene loci in 15 worldwide populations of D. melanogaster . Estimates of Nm (number of migrants exchanged per generation among populations) range from 1.09 in East-Asian populations (Taiwan, Vietnam and Australia) to 2.66 in West-Coast populations of North America. These estimates, among geographic populations separated by hundreds or even thousands of miles, suggest that gene flow among neighboring populations of D. melanogaster is quite extensive. This means that, for selectively neutral genes, we should expect little differentiation among neighboring populations. A survey of eight West-Coast populations of D. melanogaster (geographically comparable to Drosophila pseudoobscura) showed that in spite of extensive gene flow, populations of D. melanogaster show much more geographic differentiation than comparable populations of D. pseudoobscura. From this we conclude that migration in combination with natural selection rather than migration alone is responsible for the geographic uniformity of molecular polymorphisms in D. pseudoobscura.

scholarly journals A SEASONAL SURVEY OF THE GENETIC STRUCTURE IN NATURAL POPULATIONS OF DROSOPHILA MELANOGASTER

1969 ◽  
Vol 44 (4) ◽  
pp. 247-258 ◽  
Author(s):  
KAZUHIKO KOSUDA ◽  
OSAMU KITAGAWA ◽  
DAIGORO MORIWAKI
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Structure ◽  
Natural Populations
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