A Multi-level Perspective on the Evolution of Orthologs and Their Functions

Area of Science:

• Genomics
• Evolutionary Biology
• Bioinformatics

Background:

• Orthologs, genes with shared ancestry, are vital for inferring gene function across species.
• Current methods often assume ortholog functional equivalence, leading to inaccurate gene function annotation transfer.
• Functional divergence in orthologs can occur, necessitating critical evaluation.

Purpose of the Study:

• To propose a systematic framework for testing ortholog functional equivalence.
• To prevent spurious functional annotation transfer by critically evaluating orthologs.
• To integrate multiple lines of evidence for robust functional assessment.

Main Methods:

• Treating functional equivalence as a null hypothesis requiring rigorous testing.
• Integrating evidence from molecular interaction networks and biochemical activity.
• Utilizing fine-grained analyses like protein feature architecture and 3D structure comparisons.

Main Results:

• Current orthology resources often lack scalable, systematic functional divergence assessments.
• A multi-level perspective is crucial for detecting functional divergence before annotation transfer.
• The proposed framework offers methodological recommendations and practical examples.

Conclusions:

• Functional equivalence of orthologs should not be assumed but critically tested.
• A systematic, multi-evidence approach enhances the reliability of cross-species gene function annotation.
• This framework supports large-scale comparative genomics by improving annotation accuracy.