Mapping ancestral genomes with massive gene loss: a matrix sandwich problem

Area of Science:

• Genomics
• Bioinformatics
• Computational Biology

Background:

• Ancestral genome reconstruction is crucial for understanding genome evolution.
• Existing methods often fail to account for gene duplication and loss, limiting their applicability.
• This limitation prevents reconstruction of ancestors with complex evolutionary histories, like the proto-monocotyledon.

Purpose of the Study:

• To develop a novel method for ancestral genome reconstruction that explicitly incorporates gene loss.
• To enable the reconstruction of previously inaccessible ancestral genomes.
• To validate the method's accuracy and applicability across different lineages.

Main Methods:

• A mapping approach based on the 'sandwich consecutive ones matrix' combinatorial concept.
• Formulation and solution of related combinatorial optimization problems, including a heuristic solver and lower bound.
• Application to reconstruct proto-monocotyledon and ancestral boreoeutherian genomes.

Main Results:

• The proposed method successfully reconstructs the proto-monocotyledon ancestor's proto-chromosomes.
• The method's accuracy was evaluated.
• Ancestral boreoeutherian genomes were reconstructed, demonstrating the framework's versatility beyond plant paleogenomics.

Conclusions:

• The developed method effectively reconstructs ancestral genomes even with significant gene loss.
• This framework is adaptable for reconstructing diverse ancestral genomes from extant data.
• The approach enhances our ability to study large-scale genome evolution.