Transmitochondrial mice as models for primary prevention of diseases caused by mutation in the tRNA(Lys) gene

Area of Science:

• Mitochondrial genetics
• Molecular biology
• Disease modeling

Background:

• Mitochondrial diseases often involve mutations in mitochondrial tRNA genes.
• Identifying pathogenic mitochondrial DNA mutations is crucial for understanding disease mechanisms.

Purpose of the Study:

• To generate and characterize transmitochondrial mice with a specific tRNA(Lys) gene mutation.
• To investigate the pathogenesis and transmission of mitochondrial DNA mutations.
• To establish a mouse model for tRNA(Lys)-based mitochondrial diseases.

Main Methods:

• Generation of transmitochondrial mice (mito-mice) carrying a G7731A mutation in the mitochondrial tRNA(Lys) gene.
• Identification of the mutation in mouse lung carcinoma P29 cells.
• Transfer of mutated mtDNA into mouse embryonic stem cells and generation of chimeric mice.
• Analysis of maternal inheritance and segregation of mutated mtDNA in subsequent generations.
• Assessment of respiration defects and disease-related phenotypes in mito-mice.

Main Results:

• A potentially pathogenic G7731A mutation in the mitochondrial tRNA(Lys) gene was identified in P29 cells.
• P29 subclones with predominant G7731A mtDNA exhibited respiration defects.
• Generated F1 mice (mito-mice-tRNA(Lys7731)) carrying the G7731A mutation displayed maternal inheritance and segregation.
• Mito-mice-tRNA(Lys7731) with high proportions of mutated mtDNA showed respiration defects and disease phenotypes.
• Significant variation in mutated mtDNA proportion among pups suggests potential for oocyte selection in prevention.

Conclusions:

• Mito-mice-tRNA(Lys7731) are valuable models for studying mitochondrial diseases caused by tRNA(Lys) mutations.
• The study provides insights into the pathogenicity and transmission of mitochondrial tRNA mutations.
• Oocyte selection may be a viable strategy for preventing the transmission of mitochondrial diseases.