Amalgamated cross-species transcriptomes reveal organ-specific propensity in gene expression evolution

Area of Science:

• Evolutionary biology
• Genomics
• Molecular biology

Background:

• The evolution of multicellularity is linked to changes in gene expression.
• Understanding how ancestral gene expression impacts descendant expression is crucial but not well-established.

Purpose of the Study:

• To investigate the influence of ancestral gene expression on evolutionary changes in descendant expression patterns.
• To explore the role of gene duplication in shaping expression evolution.

Main Methods:

• Amalgamated 1,903 RNA-sequencing datasets from 21 vertebrate species across 6 organs.
• Implemented quality control to remove project-specific biases.
• Reconstructed expression shifts using gene-family-wise phylogenetic Ornstein-Uhlenbeck models.

Main Results:

• Gene duplication events lead to more significant expression property changes compared to non-duplication events.
• Expression properties correlate with protein evolutionary rates, influenced by gene duplication.
• Organ-specific expression patterns exhibit nonrandom modular connections, reshaped by gene duplication.

Conclusions:

• Ancestral expression in certain organs creates a propensity for specific expression patterns in descendants.
• Preadaptive pathways play a significant role in the evolution of gene expression, irrespective of adaptive pressures.