Dissecting the effects of mtDNA variations on complex traits using mouse conplastic strains

Area of Science:

• Genetics
• Mitochondrial Biology
• Mammalian Genetics

Background:

• Common inbred mouse strains (CIS) share a common maternal ancestor, with accumulated mitochondrial DNA (mtDNA) mutations.
• This genetic background offers a unique model to study the influence of individual mtDNA variations on complex traits.

Purpose of the Study:

• To investigate the impact of specific mitochondrial DNA variations on complex mammalian traits.
• To generate a comprehensive panel of conplastic mouse strains for studying mtDNA effects.

Main Methods:

• Compiled complete mtDNA sequences from 52 mouse CIS.
• Performed phylogenetic analysis to trace mtDNA origins.
• Generated conplastic strains on a C57BL/6J background for 16 distinct mtDNA variants.
• Conducted phenotypic analyses on these conplastic strains.

Main Results:

• Phylogenetic analysis confirmed a single female ancestor for 50 out of 52 CIS.
• Identified accumulated mtDNA mutations in 26 CIS.
• Demonstrated that mtDNA variations significantly affect susceptibility to experimental autoimmune encephalomyelitis and anxiety-related behaviors.
• Established a valuable resource of 16 conplastic strains for future research.

Conclusions:

• Mitochondrial DNA variations demonstrably influence complex traits in mammals.
• The generated conplastic strains provide a powerful tool for exploring the roles of mitochondria in physiology and disease.
• This research deepens our understanding of genotype-phenotype relationships influenced by mitochondrial genetics.