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Updated: Jul 5, 2026
13:47
Chromatin Immunoprecipitation (ChIP) using Drosophila tissue
Published on: March 23, 2012
Complex genetic interactions underlying expression differences between Drosophila races: analysis of chromosome
Hurng-Yi Wang1, Yonggui Fu, Mary Sara McPeek
1Graduate Institute of Clinical Medicine, National Taiwan University, 7 Chung-Shan South Road, Taipei 100, Taiwan. hurngyi@ntu.edu.tw
Summary
Gene expression regulation is complex, involving cis and trans factors. Most expression differences arise from multiple genes and interactions, not simple genetic control.
Area of Science:
- Genetics
- Evolutionary Biology
- Molecular Biology
Background:
- Gene expression regulation is typically categorized into cis and trans components.
- This separation can be artificial when multigenic and epistatic interactions (cis-by-trans) influence expression variation.
- Quantifying the interplay of cis, trans, and cis-by-trans effects is crucial for understanding evolutionary divergence in gene expression.
Purpose of the Study:
- To quantify the relative contributions of cis, trans, and cis-by-trans genetic effects on gene expression divergence across the genome.
- To investigate the evolution of gene regulation between distinct populations of Drosophila melanogaster.
Main Methods:
- Analysis of chromosome-substitution lines between two behavioral races of Drosophila melanogaster.
- Genome-wide assessment of gene expression differences and their genetic underpinnings.
Main Results:
- Only about 3% of genes with expression differences are purely cis-regulated.
- Nearly 80% of expression differences are controlled by at least two chromosomes, indicating complex genetic architectures.
- Inclusive cis effects (cis regulation combined with trans regulation) are observed in 14% of genes, increasing to 32% for strongly differentiated genes.
- A nonrandom distribution of trans-acting factors was noted, with a deficit on the second chromosome.
Conclusions:
- Gene expression regulation is predominantly controlled by complex genetic interactions rather than simple cis or trans effects alone.
- Trans regulation plays an extensive role in expression divergence between Drosophila racial groups.
- Cis regulation frequently co-evolves with trans effects, highlighting the intricate nature of regulatory evolution.
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