Related Experiment Video
Updated: Mar 1, 2026
10:00
Measurement of Lifespan in Drosophila melanogaster
Published on: January 7, 2013
35.7K
MULTIPLE GENETIC MECHANISMS FOR THE EVOLUTION OF SENESCENCE IN DROSOPHILA MELANOGASTER.
P M Service1, E W Hutchinson1, M R Rose1
1Department of Biology, Dalhousie University, Halifax, NS, B3H 4J1, CANADA.
Summary
Antagonistic pleiotropy and mutation accumulation drive senescence evolution in Drosophila melanogaster. Reverse selection revealed trade-offs in early-life fitness and stress resistance, with density-dependent effects observed.
Area of Science:
- Evolutionary Biology
- Gerontology
- Genetics
Background:
- Senescence, the decline in function with age, can evolve via antagonistic pleiotropy or mutation accumulation.
- Understanding these mechanisms is crucial for aging research.
- Drosophila melanogaster serves as a model organism for studying evolutionary genetics.
Purpose of the Study:
- To experimentally distinguish between antagonistic pleiotropy and mutation accumulation as drivers of senescence.
- To investigate the effects of reverse selection on early-life fitness and stress resistance.
- To assess the influence of larval rearing density on these evolutionary processes.
Main Methods:
- Laboratory populations of Drosophila melanogaster were subjected to selection experiments.
- Reverse selection for early-life fitness was applied to populations previously selected for late-life fitness.
- Experiments were conducted under both uncontrolled (high density) and controlled (low density) larval rearing conditions.
Main Results:
- Reverse selection increased early-age fecundity and decreased starvation resistance in uncontrolled-density lines, supporting antagonistic pleiotropy.
- Resistance to desiccation and ethanol did not decline, suggesting a role for mutation accumulation.
- Controlled-density lines showed no significant response, highlighting density-dependent selection effects.
Conclusions:
- Both antagonistic pleiotropy and mutation accumulation contribute to the evolution of senescence in Drosophila.
- Larval rearing density significantly influences the evolutionary trajectory of life-history traits.
- These findings provide a nuanced understanding of aging mechanisms in a model organism.
Related Concept Videos
02:27Background and Environment Affect Phenotype
7.9K
Although the genetic makeup of an organism plays a major role in determining the phenotype, there are also several environmental factors, such as temperature, oxygen availability, presence of mutagens, that can alter an organism’s phenotype.
An example of how genetic background affects phenotype can be seen in horses. The Extension gene in horses is responsible for their coat color. A wild-type gene (EE) produces black pigment in the coat, while a mutant gene (ee) produces red pigment. A...
An example of how genetic background affects phenotype can be seen in horses. The Extension gene in horses is responsible for their coat color. A wild-type gene (EE) produces black pigment in the coat, while a mutant gene (ee) produces red pigment. A...
7.9K
02:45The Ratio of X Chromosome to Autosomes
9.9K
In most organisms, sex is determined by the ratio of X and Y chromosomes. However, in some organisms, such as Drosophila and C.elegans, sex is determined by the ratio of the number of X chromosomes to the number of sets of autosomes. The Y chromosome in Drosophila is active but does not determine sex. It contains genes responsible for the production of sperms in adult flies.
Normal male Drosophila has a ratio of one X chromosome to two sets of autosomes. In contrast, normal female...
Normal male Drosophila has a ratio of one X chromosome to two sets of autosomes. In contrast, normal female...
9.9K
02:32Exon Recombination
4.2K
The evolution of new genes is critical for speciation. Exon recombination, also known as exon shuffling or domain shuffling, is an important means of new gene formation. It is observed across vertebrates, invertebrates, and in some plants such as potatoes and sunflowers. During exon recombination, exons from the same or different genes recombine and produce new exon-intron combinations, which might evolve into new genes.
Exon shuffling follows “splice frame rules.” Each exon...
Exon shuffling follows “splice frame rules.” Each exon...
4.2K
02:50Dosage Compensation
7.7K
In animals, gender is determined by the number and type of sex chromosome. For example, human females have two X chromosomes, and males have one X and one Y chromosome, whereas C.elegans with one X chromosome is a male, and the one with two X chromosomes is a hermaphrodite.
In addition to sexual development, the X chromosome has genes involved in autosomal functions such as brain development and the immune system. Therefore, males and females with distinct numbers of X chromosomes will...
In addition to sexual development, the X chromosome has genes involved in autosomal functions such as brain development and the immune system. Therefore, males and females with distinct numbers of X chromosomes will...
7.7K