Sex systems boost mitochondrial evolution in many kinds of insects, PgII

Key Highlights:

• Researchers discovered a link between chromosome sets and mitochondrial DNA evolution in insects.
• Haplo-diploid (HD) insect species show faster COI gene evolution compared to diplo-diploid (DD) species.
• The study surveyed 86,000 insect species from 783 families across 26 orders.
• HD species exhibit approximately 1.7 times more changes in the COI protein than DD species.

Detailed Insights:

• Mitochondrial DNA (mtDNA) evolution is typically linked to mutation rate, metabolism, and population size, but this study reveals a connection to chromosome number.
• Haplo-diploid (HD) sex determination, where females are diploid and males are haploid, is common in Hymenoptera (ants, bees, wasps) and Thysanoptera.
• The COI gene, located in the mitogenome, is crucial for cell energy production, and its faster evolution in HD species may affect insect biodiversity tracking.
• In HD species, mutations in nuclear genes have immediate effects on males, potentially driving faster evolution of interacting mitochondrial genes.
• The study suggests that selection pressures on nuclear genes in haploid males may accelerate the evolution of mitochondrial genes involved in energy production.

Scientific/Technical Concepts Involved:

• Mitochondrial DNA (mtDNA): The DNA located in mitochondria, responsible for energy production within cells.
• Haplo-diploid (HD): A sex-determination system where females are diploid (two sets of chromosomes) and males are haploid (one set).
• Diplo-diploid (DD): A sex-determination system where both males and females are diploid, differing by sex chromosomes.
• COI gene: Cytochrome c oxidase subunit I gene, a key mitochondrial gene used in species identification and evolutionary studies.