A genetic analysis of path length and pupation height in a natural population of Drosophila melanogaster

Behaviour–genetic studies using laboratory strains of Drosophila are often criticized because the results cannot be generalized to natural populations. The genetic component of variation in two prepupal behaviours was studied for strains derived from a natural population of Drosophila melanogaster. These strains showed a second-chromosome based contribution to differences in path length (the distance a larva crawls in a yeasted culture dish) with the long path length phenotype dominant over the short. Differences in pupation height (the distance a larva pupates above the surface of the medium) were affected not only by the second chromosomes but also by the third pair of chromosomes. The second pair influenced the differences in pupation height threefold more than the third. Intermediate pupation heights were found in the reciprocal crosses. While path lengths could be replicated in their absolute scores over different days, pupation heights could only be replicated in their relative scores.Key words: larval behaviour, Drosophila, natural population, genetics.

Download Full-text

GENETIC AND BIOCHEMICAL BASIS OF ENZYME ACTIVITY VARIATION IN NATURAL POPULATIONS. I. ALCOHOL DEHYDROGENASE IN DROSOPHILA MELANOGASTER

Genetics ◽

10.1093/genetics/89.2.371 ◽

1978 ◽

Vol 89 (2) ◽

pp. 371-388

Author(s):

John F McDonald ◽

Francisco J Ayala

Keyword(s):

Gene Regulation ◽

Drosophila Melanogaster ◽

Alcohol Dehydrogenase ◽

Natural Populations ◽

Difficult Problem ◽

Regulatory Genes ◽

Biochemical Basis ◽

Evolutionary Consequence ◽

The Third ◽

Adh Activity

ABSTRACT Recent studies by various authors suggest that variation in gene regulation may be common in nature, and might be of great evolutionary consequence; but the ascertainment of variation in gene regulation has proven to be a difficult problem. In this study, we explore this problem by measuring alcohol dehydrogenase (ADH) activity in Drosophila melanogaster strains homozygous for various combinations of given second and third chromosomes sampled from a natural population. The structural locus (Adh) coding for ADH is on the second chromosome. The results show that: (1) there are genes, other than Adh, that affect the levels of ADH activity; (2) at least some of these "regulatory" genes are located on the third chromosome, and thus are not adjacent to the Adh locus; (3) variation exists in natural populations for such regulatory genes; (4) the effect of these regulatory genes varies as they interact with different second chromosomes; (5) third chromosomes with high-activity genes are either partially or completely dominant over chromosomes with low-activity genes; (6) the effects of the regulatory genes are pervasive throughout development; and (7) the third chromosome genes regulate the levels of ADH activity by affecting the number of ADH molecules in the flies. The results are consistent with the view that the evolution of regulatory genes may play an important role in adaptation.

Download Full-text

GENETIC LOAD IN NATURAL POPULATIONS: IS IT COMPATIBLE WITH THE HYPOTHESIS THAT MANY POLYMORPHISMS ARE MAINTAINED BY NATURAL SELECTION?

Genetics ◽

10.1093/genetics/77.3.569 ◽

1974 ◽

Vol 77 (3) ◽

pp. 569-589

Author(s):

Martin L Tracey ◽

Francisco J Ayala

Keyword(s):

Drosophila Melanogaster ◽

Natural Selection ◽

Natural Population ◽

Natural Populations ◽

Genetic Load ◽

Structural Genes ◽

Invertebrate Species ◽

Average Proportion ◽

Mean Fitness ◽

The Mean

ABSTRACT Recent studies of genetically controlled enzyme variation lead to an estimation that at least 30 to 60% of the structural genes are polymorphic in natural populations of many vertebrate and invertebrate species. Some authors have argued that a substantial proportion of these polymorphisms cannot be maintained by natural selection because this would result in an unbearable genetic load. If many polymorphisms are maintained by heterotic natural selection, individuals with much greater than average proportion of homozygous loci should have very low fitness. We have measured in Drosophila melanogaster the fitness of flies homozygous for a complete chromosome relative to normal wild flies. A total of 37 chromosomes from a natural population have been tested using 92 experimental populations. The mean fitness of homozygous flies is 0.12 for second chromosomes, and 0.13 for third chromosomes. These estimates are compatible with the hypothesis that many (more than one thousand) loci are maintained by heterotic selection in natural populations of D. melanogaster.

Download Full-text

Studies of esterase 6 in Drosophila melanogaster: XIV. Variation of esterase 6 levels controlled by unlinked genes in natural populations

Genetics Research ◽

10.1017/s0016672300025891 ◽

1984 ◽

Vol 43 (2) ◽

pp. 181-190 ◽

Cited By ~ 7

Author(s):

Craig S. Tepper ◽

Anne L. Terry ◽

James E. Holmes ◽

Rollin C. Richmond

Keyword(s):

Drosophila Melanogaster ◽

Structural Gene ◽

X Chromosome ◽

Genetic Background ◽

Natural Populations ◽

Regulatory Elements ◽

Regulatory Locus ◽

The Third ◽

Esterase 6 ◽

Activity Modifiers

SUMMARYThe esterase 6 (Est-6) locus in Drosophila melanogaster is located on the third chromosome and is the structural gene for a carboxylesterase (E.C.3.1.1.1) and is polymorphic for two major electromorphs (slow and fast). Isogenic lines containing X chromosomes extracted from natural populations and substituted into a common genetic background were used to detect unlinked factors that affect the activity of the Est-6 locus. Twofold activity differences of esterase 6 (EST 6) were found among males from these derived lines, which differ only in their X chromosome. These unlinked activity modifiers identify possible regulatory elements. Immunoelectrophoresis was used to estimate quantitatively the levels of specific cross-reacting material in the derived lines. The results show that the variation in activity is due to differences in the amount of EST 6 present. The data are consistent with the hypothesis that there is at least one locus on the X chromosome that regulates the synthesis of EST 6 and that this regulatory locus may be polymorphic in natural populations.

Download Full-text

GENETIC ANALYSIS OF NATURAL POPULATIONS OF DROSOPHILA MELANOGASTER IN JAPAN. II. THE MEASUREMENT OF FITNESS AND FITNESS COMPONENTS IN HOMOZYGOUS LINES

Genetics ◽

10.1093/genetics/108.1.213 ◽

1984 ◽

Vol 108 (1) ◽

pp. 213-221 ◽

Cited By ~ 1

Author(s):

Tsuneyuki Yamazaki ◽

Yasuko Hirose

Keyword(s):

Drosophila Melanogaster ◽

Genetic Analysis ◽

Natural Population ◽

Natural Populations ◽

Distribution Patterns ◽

Developmental Time ◽

Fitness Components ◽

Isogenic Lines ◽

Genetic Structures

ABSTRACT Fifty lethal-free, sterility-free isogenic lines of Drosophila melanogaster that were randomly sampled from a natural population were tested for net fitness and other components of fitness by competition with D. hydei. Larval viability and developmental time were also measured using the balanced marker method. Distribution patterns of these fitness components were similar, but correlation between the fitness components varied depending on the combinations used. The highest correlations were obtained between net fitness and productivity (rp = 0.6987, rg = 0.9269). The correlation between net fitness and total larval viability was much lower (rp = 0.1473 and rg = 0.2171). These results indicate that measuring net fitness, not just a component of fitness, is necessary for the good understanding of the genetic structures of natural populations.

Download Full-text

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

Genetics Research ◽

10.1017/s0016672300018711 ◽

1978 ◽

Vol 32 (3) ◽

pp. 215-229 ◽

Cited By ~ 19

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.

Download Full-text

Effects of autosomal inversions on meiotic exchange in distal and proximal regions of the X chromosome in a natural population of Drosophila melanogaster

Genetics Research ◽

10.1017/s0016672300032080 ◽

1994 ◽

Vol 63 (1) ◽

pp. 57-62 ◽

Cited By ~ 6

Author(s):

Paul D. Sniegowski ◽

Anne Pringle ◽

Kimberly A. Hughes

Keyword(s):

Drosophila Melanogaster ◽

Natural Population ◽

X Chromosome ◽

Natural Populations ◽

Element Abundance ◽

Recombination Rates ◽

Interchromosomal Effect ◽

Naturally Occurring ◽

Study Population ◽

Transposable Element Abundance

SummaryWe have investigated the interchromosomal effect of the naturally-occurring paracentric inversions In(2L)t and In(3R)P on meiotic recombination in two regions of the X chromosome in Drosophila melanogaster. Previous authors have suggested that the rate of recombination at the tip of the X chromosome may be substantially higher in some natural populations than values measured in the laboratory, due to the interchromosomal effect of heterozygous autosomal inversions. This suggestion was motivated by observations that transposable elements are not as common at the tip of the X chromosome as predicted by recent research relating reduced meiotic exchange to increased element abundance in D. melanogaster. We examined the effects of heterozygous In(2L)t and In(3R)P on recombination at both the tip and base of the X chromosome on a background of isogenic major chromosomes from a natural population. Both inversions substantially increased the rate of recombination at the base; neither one affected recombination at the tip. The results suggest that the presence of inversions in the study population does not elevate rates of crossing over at the tip of the X chromosome. The relevance of these results to ideas relating transposable element abundance to recombination rates is discussed.

Download Full-text

THE ORGANIZATION OF GENETIC VARIATION FOR RECOMBINATION IN DROSOPHILA MELANOGASTER

Genetics ◽

10.1093/genetics/114.2.525 ◽

1986 ◽

Vol 114 (2) ◽

pp. 525-547

Author(s):

Lisa D Brooks ◽

R William Marks

Keyword(s):

Drosophila Melanogaster ◽

Genetic Variation ◽

Natural Population ◽

Small Region ◽

Crossing Over ◽

Fine Scale ◽

Response To Selection ◽

Natural Genetic Variation ◽

The Third ◽

Scale Response

ABSTRACT The amount and form of natural genetic variation for recombination were studied in six lines for which second chromosomes were extracted from a natural population of Drosophila melanogaster. Multiply marked second, Χ and third chromosomes were used to score recombination. Recombination in the second chromosomes varied in both amount and distribution. These second chromosomes caused variation in the amount and distribution of crossing over in the Χ chromosome and also caused variation in the amount, but not the distribution, of crossing over in the third chromosome. The total amount of crossing over on a chromosome varied by 12-14%. One small region varied twofold; other regions varied by 16-38%. Lines with less crossing over on one chromosome generally had less crossing over on other chromosomes, the opposite of the standard interchromosomal effect. These results show that modifiers of recombination can affect more than one chromosome, and that the variation exists for fine-scale response to selection on recombination.

Download Full-text

LINKAGE DISEQUILIBRIUM IN NATURAL POPULATIONS OF DROSOPHILA MELANOGASTER. SEASONAL VARIATION

Genetics ◽

10.1093/genetics/86.2.447 ◽

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.

Download Full-text

A factor on a wild third chromosome (IIIRa) that modifies the Segregation Distortion phenomenon in Drosophila melanogaster

Genetics Research ◽

10.1017/s0016672300015925 ◽

1975 ◽

Vol 26 (2) ◽

pp. 113-125 ◽

Cited By ~ 7

Author(s):

G. Trippa ◽

A. Loverre

Keyword(s):

Drosophila Melanogaster ◽

Natural Population ◽

Segregation Distortion ◽

Southern Italy ◽

Genetic Modifier ◽

Natural Populations ◽

Dominant Effect ◽

Chromosome Iii ◽

Very High

SUMMARYIIIRa is a genetic modifier of Segregation Distortion (SD) in Drosophila melanogaster, which was discovered in the same natural population from Ranna (Sicily) that carried SDRa. It is located at 49·7 ± 0·8 on chromosome III. IIIRa was found to have a dominant effect on segregation distortion which varied with the origin of the SD chromosome tested. Thus it enhanced the level of distortion caused by 14 SD chromosomes from seven natural populations in Southern Italy and Sicily, but decreased the level of distortion caused by SDR−1, a chromosome from a natural population near Rome. Moreover, IIIRa determined or enhanced the distorting effect of SDRa in males heterozygous for SDRa and various SD+ wild chromosomes differently sensitive to SDRa. The frequency of chromosomes having an effect like IIIRa chromosome was very high (around 70%) in samples from two natural populations of Southern Italy tested-those of Ranna and Corato. No effects of IIIRa other than its ability to modify SD have been detected.

Download Full-text

Distribution of Nonrandom Associations Between Pairs of Protein Loci Along the Third Chromosome of Drosophila melanogaster

Genetics ◽

10.1093/genetics/161.4.1539 ◽

2002 ◽

Vol 161 (4) ◽

pp. 1539-1550 ◽

Cited By ~ 1

Author(s):

Carlos Zapata ◽

Concepción Núñez ◽

Teresa Velasco

Keyword(s):

Drosophila Melanogaster ◽

Statistical Power ◽

Neutral Theory ◽

Natural Populations ◽

Estimation Method ◽

Antioxidant Defense System ◽

Hormonal Control ◽

Long Distance ◽

The Third ◽

Outcrossing Species

Abstract The within-chromosome distribution of gametic disequilibrium (GD) between protein loci, and the underlying evolutionary factors of this distribution, are still largely unknown. Here, we report a detailed study of GD between a large number of protein loci (15) spanning 87% of the total length of the third chromosome of Drosophila melanogaster in a large sample of haplotypes (600) drawn from a single natural population. We used a sign-based GD estimation method recently developed for multiallelic systems, which considerably increases both the statistical power and the accuracy of estimation of the intensity of GD. We found that strong GD between pairs of protein loci was widespread throughout the chromosome. In total, 22% of both the pairs of alleles and pairs of loci were in significant GD, with mean intensities (as measured by D′ coefficients) of 0.43 and 0.31, respectively. In addition, strong GD often occurs between loci that are far apart. By way of illustration, 32% of the allele pairs in significant GD occurred within pairs of loci separated by effective frequencies of recombination (EFRs) of 15–20 cM, the mean D′ value being 0.49. These observations are in sharp contrast with previous studies showing that GD between protein loci is rarely found in natural populations of outcrossing species, even between very closely linked loci. Interestingly, we found that most instances of significant interallelic GD (68%) involved functionally related protein loci. Specifically, GD was markedly more frequent between protein loci related by the functions of hormonal control, molybdenum control, antioxidant defense system, and reproduction than between loci without known functional relationship, which is indicative of epistatic selection. Furthermore, long-distance GD between functionally related loci (mean EFR 9 cM) suggests that epistatic interactions must be very strong along the chromosome. This evidence is hardly compatible with the neutral theory and has far-reaching implications for understanding the multilocus architecture of the functional genome. Our findings also suggest that GD may be a useful tool for discovering networks of functionally interacting proteins.

Download Full-text