Selective and non-selective evolutionary signatures found in the simplest replicative biological entities.

Area of Science:

• Virology
• Molecular Evolution
• Bioinformatics

Background:

• Mitoviruses are simple RNA viruses, considered relics of extinct alpha-proteobacteria RNA phages.
• Understanding their genomic characteristics is key to their classification and evolutionary history.

Purpose of the Study:

• To quantitatively describe mitovirus genomes.
• To identify genomic signatures supporting protein phylogenetic classification.
• To investigate evolutionary pressures and structural divergence.

Main Methods:

• Analysis of mononucleotide and dinucleotide composition.
• Assessment of codon usage bias.
• Calculation of minimal free energy for RNA secondary structures.
• Application of energy minimization for 2D folding analysis.

Main Results:

• Natural selection and neutral evolution significantly shape mitovirus genomes.
• Identified distinct spatial genome organization and structural divergence in Kvaramitovirus.
• Provided evidence supporting a single evolutionary circularization event in the lineage's common ancestor.

Conclusions:

• Mitovirus genomes are quantitatively described at family and genus levels.
• Structural divergence in Kvaramitovirus offers insights into their evolutionary path.
• Generated experimentally verifiable hypotheses for future mitovirus research.