Chimeric protein complexes in hybrid species generate novel phenotypes

Area of Science:

• Evolutionary biology
• Molecular biology
• Genetics

Background:

• Hybridization is a key driver of evolutionary novelty and adaptation.
• Phenotypic variation in hybrids is attributed to allelic variation and transcriptional changes.
• Protein complexes, crucial for cellular functions, represent an understudied source of variation in hybrids.

Purpose of the Study:

• To investigate the formation of chimeric protein complexes in inter-specific hybrids.
• To determine if these hybrid complexes can freely assemble despite co-evolutionary forces.
• To assess the impact of different chimeric complexes on hybrid fitness in varying environments.

Main Methods:

• Studied six protein complexes in two Saccharomyces hybrids.
• Isolated protein assemblies using affinity chromatography.
• Identified complex composition via mass spectrometry.

Main Results:

• Found spontaneous chimericity in four out of six tested protein assemblies.
• Demonstrated that different chimeric complexes lead to varied phenotypes.
• Observed fitness advantages in specific environments due to chimeric complexes (e.g., TRP2/TRP3, MBF).

Conclusions:

• Chimeric protein complexes can assemble spontaneously in hybrid cells.
• This provides a novel mechanism for generating phenotypic novelty and plasticity.
• Inter-specific protein complex formation has significant implications for hybrid adaptation and genome evolution.