High-resolution genomic analysis of human mitochondrial RNA sequence variation.

Alan Hodgkinson, Youssef Idaghdour, Elias Gbeha, Jean-Christophe Grenier, Elodie Hip-Ki, Vanessa Bruat, Jean-Philippe Goulet, Thibault de Malliard, Philip Awadalla

Index: Science 344(6182) , 413-5, (2014)

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Abstract

Mutations in the mitochondrial genome are associated with multiple diseases and biological processes; however, little is known about the extent of sequence variation in the mitochondrial transcriptome. By ultra-deeply sequencing mitochondrial RNA (>6000×) from the whole blood of ~1000 individuals from the CARTaGENE project, we identified remarkable levels of sequence variation within and across individuals, as well as sites that show consistent patterns of posttranscriptional modification. Using a genome-wide association study, we find that posttranscriptional modification of functionally important sites in mitochondrial transfer RNAs (tRNAs) is under strong genetic control, largely driven by a missense mutation in MRPP3 that explains ~22% of the variance. These results reveal a major nuclear genetic determinant of posttranscriptional modification in mitochondria and suggest that tRNA posttranscriptional modification may affect cellular energy production.