The effect of transposable element insertions on gene expression evolution in rodents

Area of Science:

• Genomics
• Evolutionary Biology
• Molecular Biology

Background:

• Genomes contain numerous transposable elements (TEs).
• Some TEs regulate gene expression.
• Conserved non-genic sequences often resemble TEs, hinting at their evolutionary role.

Purpose of the Study:

• Investigate if new TE insertions influence gene expression profiles.
• Test the correlation between gene expression divergence and new TE insertions near genes in mice and rats.

Main Methods:

• Comparative analysis of gene expression divergence between mouse and rat.
• Quantification of new transposable element insertions (LTR, SINE, LINE) near genes.
• Statistical correlation analysis.

Main Results:

• Expression divergence significantly correlates with new LTR and SINE element insertions.
• No significant correlation found with LINE element insertions.
• Expression divergence is not significantly correlated with ancestral TEs, supporting a causal role for new insertions.
• TE insertion accounts for ~20% of expression profile divergence in rodents.

Conclusions:

• Transposable element insertions have a major impact on the evolution of gene expression levels in rodents.
• New TE insertions are a significant driver of gene expression evolution.