Related Experiment Video
Updated: Jul 11, 2026
04:52
Following the Dynamics of Structural Variants in Experimentally Evolved Populations
Published on: February 3, 2023
Evolution of gene sequence in response to chromosomal location
Carlos Díaz-Castillo1, Kent G Golic
1Department of Biology, University of Utah, Salt Lake City, Utah 84112, USA. diazcastillo@biology.utah.edu
Genetics
|September 25, 2007
Summary
Protein-coding genes in Drosophila melanogaster evolve differently based on their location in euchromatin or heterochromatin. Genes near heterochromatin show reduced CG content and increased DNA sequence variation, likely driven by DNA methylation.
Area of Science:
- Genetics
- Evolutionary Biology
- Molecular Biology
Background:
- Repetitive DNA in heterochromatin evolves rapidly due to different evolutionary forces than protein-coding genes.
- Chromosomal location can influence gene evolution, but its impact on protein-coding sequences within heterochromatin is less understood.
Purpose of the Study:
- To investigate how chromosomal location affects the evolution of protein-coding genes.
- To examine the DNA sequence characteristics of euchromatic and heterochromatic members of the Troponin C gene family in Drosophila melanogaster.
Main Methods:
- Comparative analysis of the Troponin C gene family in Drosophila melanogaster.
- Assessment of CG content and DNA sequence variation in euchromatic and heterochromatic gene regions.
- Correlation analysis between CG content, gene location, and distance from heterochromatin.
Main Results:
- Heterochromatic members of the Troponin C gene family exhibit reduced CG content and increased DNA sequence variation.
- A broad reduction in CG content is observed in protein-coding sequences at the heterochromatin:euchromatin interface.
- A strong correlation exists between CG content and proximity to centric heterochromatin, as well as telomeric heterochromatin.
Conclusions:
- Protein-coding genes evolve in response to their chromosomal location, particularly near heterochromatin.
- DNA methylation is proposed as a key evolutionary force driving sequence changes in genes located at the heterochromatin:euchromatin boundary.
- Chromosomal environment significantly impacts gene sequence evolution beyond the constraints of protein-coding function.
More Related Videos
Related Concept Videos
02:05Gene Evolution - Fast or Slow?
The genomes of eukaryotes are punctuated by long stretches of sequence which do not code for proteins or RNAs. Although some of these regions do contain crucial regulatory sequences, the vast majority of this DNA serves no known function. Typically, these regions of the genome are the ones in which the fastest change, in evolutionary terms, is observed, because there is typically little to no selection pressure acting on these regions to preserve their sequences.
In contrast, regions which code...
In contrast, regions which code...
02:05Gene Evolution - Fast or Slow?
The genomes of eukaryotes are punctuated by long stretches of sequence which do not code for proteins or RNAs. Although some of these regions do contain crucial regulatory sequences, the vast majority of this DNA serves no known function. Typically, these regions of the genome are the ones in which the fastest change, in evolutionary terms, is observed, because there is typically little to no selection pressure acting on these regions to preserve their sequences.
In contrast, regions which code...
In contrast, regions which code...
02:08Gene Conversion
Other than maintaining genome stability via DNA repair, homologous recombination plays an important role in diversifying the genome. In fact, the recombination of sequences forms the molecular basis of genomic evolution. Random and non-random permutations of genomic sequences create a library of new amalgamated sequences. These newly formed genomes can determine the fitness and survival of cells. In bacteria, homologous and non-homologous types of recombination lead to the evolution of new...
02:08Gene Conversion
Other than maintaining genome stability via DNA repair, homologous recombination plays an important role in diversifying the genome. In fact, the recombination of sequences forms the molecular basis of genomic evolution. Random and non-random permutations of genomic sequences create a library of new amalgamated sequences. These newly formed genomes can determine the fitness and survival of cells. In bacteria, homologous and non-homologous types of recombination lead to the evolution of new...
02:35Chromatin Position Affects Gene Expression
Chromatin is the massive complex of DNA and proteins packaged inside the nucleus. The complexity of chromatin folding and how it is packaged inside the nucleus greatly influences access to genetic information. Generally, the nucleus' periphery is considered transcriptionally repressive, while the cell's interior is considered a transcriptionally active area.
Topologically Associated Domains (TADs)
The 3-dimensional positioning of chromatin in the nucleus influences the timing and level of...
Topologically Associated Domains (TADs)
The 3-dimensional positioning of chromatin in the nucleus influences the timing and level of...
03:21Genome Size and the Evolution of New Genes
While every living organism has a genome of some kind (be it RNA, or DNA), there is considerable variation in the sizes of these blueprints. One major factor that impacts genome size is whether the organism is prokaryotic or eukaryotic. In prokaryotes, the genome contains little to no non-coding sequence, such that genes are tightly clustered in groups or operons sequentially along the chromosome. Conversely, the genes in eukaryotes are punctuated by long stretches of non-coding sequence.