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Updated: Jul 6, 2026
04:52
Following the Dynamics of Structural Variants in Experimentally Evolved Populations
Published on: February 3, 2023
Both selective and neutral processes drive GC content evolution in the human genome.
Uberto Pozzoli1, Giorgia Menozzi, Matteo Fumagalli
1Scientific Institute IRCCS E, Medea, Bioinformatic Lab, Via don L, Monza 20, 23842 Bosisio Parini (LC), Italy. uberto.pozzoli@bp.lnf.it
BMC Evolutionary Biology
|March 29, 2008
Summary
GC content variation in mammalian genomes is influenced by both biased gene conversion (BGC) and selection. This study reveals isochore-specific correlations, suggesting a dual mechanism shapes genome composition.
Area of Science:
- Genomics
- Evolutionary Biology
- Molecular Biology
Background:
- Mammalian genomes exhibit regional differences in GC content, known as isochores or GC-content domains.
- The evolutionary origin of this compositional heterogeneity (selected vs. neutral) remains debated.
Purpose of the Study:
- To investigate the roles of biased gene conversion (BGC) and selection in driving GC content variation within mammalian genomes.
- To reconcile contrasting findings on GC content evolution by proposing a unified model.
Main Methods:
- Analysis of single nucleotide polymorphism (SNP) allele frequencies.
- Examination of retrotransposon insertion polymorphisms (RIPs).
- Assessment of fixed substitutions in the human lineage and intron GC content/size correlations.
Main Results:
- Evidence suggests biased gene conversion (BGC) contributes to GC content variation.
- A distinct contribution from selective processes was identified.
- Intron GC content and size show isochore-specific correlations after correcting for biases.
Conclusions:
- GC content in the human genome is shaped by both weak selection and BGC.
- Selective processes may target features like nucleosome positioning or chromatin conformation.
- This dual mechanism reconciles previous findings and supports GC-rich domains' distinct biological roles.
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