Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Mutation, Gene Flow, and Genetic Drift01:09

Mutation, Gene Flow, and Genetic Drift

In a population that is not at Hardy-Weinberg equilibrium, the frequency of alleles changes over time. Therefore, any deviations from the five conditions of Hardy-Weinberg equilibrium can alter the genetic variation of a given population. Conditions that change the genetic variability of a population include mutations, natural selection, non-random mating, gene flow, and genetic drift (small population size).Mechanisms of Genetic VariationThe original sources of genetic variation are mutations,...
Genetic Variation01:25

Genetic Variation

Genetic variation is the diversity in DNA sequences found among individuals of the same species. This diversity is crucial for a species' survival because it helps organisms adapt to environmental changes. Genetic variation begins with fertilization, where an egg and sperm cell merge. Each of these cells carries 23 chromosomes, up to 46 in the fertilized egg. Chromosomes are long DNA strands that contain genes, the basic units of heredity.
Genes exist in different versions called alleles, which...
Position-effect Variegation02:32

Position-effect Variegation

In 1928, a German botanist Emil Heitz observed the moss nuclei with a DNA binding dye. He observed that while some chromatin regions decondense and spread out in the interphase nucleus, others do not. He termed them euchromatin and heterochromatin, respectively. He proposed that the heterochromatin regions reflect a functionally inactive state of the genome. It was later confirmed that heterochromatin is transcriptionally repressed, and euchromatin is transcriptionally active chromatin.
The Ratio of X Chromosome to Autosomes02:45

The Ratio of X Chromosome to Autosomes

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 Drosophila...
Genetic Screens02:46

Genetic Screens

Genetic screens are tools used to identify genes and mutations responsible for phenotypes of interest. Genetic screens help identify individuals or a group of people at risk of developing  genetic diseases and help them with early intervention, targeted therapy, and reproductive options.
Forward genetic screens
Forward or “classical” genetic screens involve creating random mutations in an organism’s DNA using radiation, mutagens, or insertion of additional bases, which result in visible changes...
What is Population Genetics?01:25

What is Population Genetics?

A population is composed of members of the same species that simultaneously live and interact in the same area. When individuals in a population breed, they pass down their genes to their offspring. Many of these genes are polymorphic, meaning that they occur in multiple variants. Such variations of a gene are referred to as alleles. The collective set of all the alleles within a population is known as the gene pool.While some alleles of a given gene might be observed commonly, other variants...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Multiome Profiling Reveals Astrocyte and Neuroendocrine Targets of Prenatal Acoustic Programming in Zebra Finch Embryos.

bioRxiv : the preprint server for biology·2026
Same author

Remote Language Assessment in School-Age Children With Phelan-McDermid Syndrome and Genotype-Phenotype Correlation.

American journal of medical genetics. Part A·2026
Same author

Selection for Postponed Senescence in Drosophila melanogaster Reveals Distinct Metabolic Aging Trajectories Modifiable by the Angiotensin-Converting Enzyme Inhibitor Lisinopril.

Aging cell·2026
Same author

Systems genetics of lifespan and senescence in Drosophila melanogaster.

BMC biology·2025
Same author

Angiotensin-Converting Enzyme Inhibitors and Metabolic Aging: A Drosophila Perspective.

Biomolecules·2025
Same author

Single nuclei transcriptomics reveals cellular diversity in TSC subependymal giant cell astrocytomas.

iScience·2025

Related Experiment Video

Updated: Jun 14, 2026

Why Quantification Matters: Characterization of Phenotypes at the Drosophila Larval Neuromuscular Junction
10:41

Why Quantification Matters: Characterization of Phenotypes at the Drosophila Larval Neuromuscular Junction

Published on: May 12, 2016

Mutations and quantitative genetic variation: lessons from Drosophila.

Trudy F C Mackay1

  • 1Department of Genetics, W. M. Keck Center for Behavioral Biology, North Carolina State University, , Campus Box 7614, Raleigh, NC 27697, USA. trudy_mackay@ncsu.edu

Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
|March 24, 2010
PubMed
Summary

Understanding genetic variation maintenance in populations is key. Studies in Drosophila reveal variation arises from rare deleterious alleles and antagonistic pleiotropy, but complex genetic architectures remain.

More Related Videos

Quantifying Abdominal Pigmentation in Drosophila melanogaster
08:41

Quantifying Abdominal Pigmentation in Drosophila melanogaster

Published on: June 1, 2017

Quantitative Comparison of cis-Regulatory Element (CRE) Activities in Transgenic Drosophila melanogaster
08:19

Quantitative Comparison of cis-Regulatory Element (CRE) Activities in Transgenic Drosophila melanogaster

Published on: December 19, 2011

Related Experiment Videos

Last Updated: Jun 14, 2026

Why Quantification Matters: Characterization of Phenotypes at the Drosophila Larval Neuromuscular Junction
10:41

Why Quantification Matters: Characterization of Phenotypes at the Drosophila Larval Neuromuscular Junction

Published on: May 12, 2016

Quantifying Abdominal Pigmentation in Drosophila melanogaster
08:41

Quantifying Abdominal Pigmentation in Drosophila melanogaster

Published on: June 1, 2017

Quantitative Comparison of cis-Regulatory Element (CRE) Activities in Transgenic Drosophila melanogaster
08:19

Quantitative Comparison of cis-Regulatory Element (CRE) Activities in Transgenic Drosophila melanogaster

Published on: December 19, 2011

Area of Science:

  • Evolutionary quantitative genetics
  • Population genetics
  • Molecular genetics

Background:

  • Maintaining genetic variation for quantitative traits is a central problem in evolutionary biology.
  • Theoretical models require estimates of genetic variation, correlations, pleiotropy, inbreeding depression, mutation rates, and selection.
  • Drosophila melanogaster studies offer insights into genetic variation maintenance.

Purpose of the Study:

  • To investigate the sources and mechanisms maintaining genetic variation for quantitative traits in natural populations.
  • To clarify the nature of segregating variation for traits under stabilizing selection.
  • To understand the complex genetic architectures underlying quantitative traits.

Main Methods:

  • Analysis of genetic variation, genetic correlations, pleiotropy, inbreeding depression, mutation rates, and selection.
  • Utilizing studies in Drosophila melanogaster.
  • Reviewing recent findings on genetic architectures and molecular polymorphisms.

Main Results:

  • A significant fraction of fitness-related trait variation in Drosophila is due to rare deleterious alleles under mutation-selection balance.
  • Antagonistic pleiotropy and late-age-specific effects contribute to variation at intermediate allele frequencies.
  • Quantitative traits exhibit complex genetic architectures with numerous pleiotropic genes and context-specific allelic effects.

Conclusions:

  • Genetic variation is maintained by a combination of mutation-selection balance and pleiotropic effects.
  • The genetic basis of quantitative traits is complex, involving many genes with context-dependent effects.
  • Future genome-wide association studies in Drosophila are crucial for empirical data on the molecular genetic basis of quantitative traits.