Dynamics of Expression Variability Contribute to Retention of Small-Scale vs. Whole-Genome Duplicates

Area of Science:

• Genomics
• Molecular Biology
• Evolutionary Biology

Background:

• Gene duplication is a major driver of evolutionary innovation in eukaryotes.
• Mechanisms governing the retention and functional bias of gene duplicates, particularly in environmental responses, are not fully understood.

Purpose of the Study:

• To investigate the role of within-line expression variation, termed expression variability, in determining gene duplicate retention.
• To explore how expression variability differs between singleton genes and their duplicates.
• To compare the functional outcomes and expression variability profiles of small-scale duplications (SSDs) and whole-genome duplications (WGDs).

Main Methods:

• Comparative genomic analysis of gene expression data.
• Quantification and comparison of expression variability between singleton genes and gene duplicates.
• Analysis of expression variability patterns across different duplication types (SSDs and WGDs) and over time.

Main Results:

• Genes with duplicates generally exhibit higher expression variability compared to singleton genes.
• Small-scale duplications and whole-genome duplications show distinct functional consequences and time-dependent expression variability profiles.
• Expression variability is higher in duplicates involved in environmental responses.

Conclusions:

• Expression variability may serve as a key factor facilitating gene expression divergence and the retention of gene duplicates.
• This mechanism could explain the functional gains observed in environmental response genes following duplication events, particularly small-scale duplications.