Interpretive Summary: Influence of environmental factors and genetic variation on mitochondrial DNA copy number

By: Leticia P. Sanglard, Larry A. Kuehn, Warren M. Snelling, and Matthew L. Spangler

Mitochondrial DNA copy number (mtDNA CN) is related to mitochondrial function and thus may be indicative of energy efficiency. This study investigated the genetic and non-genetic factors associated with mtDNA CN in a beef cattle population of 2,371 animals using whole-genome sequencing at low depth. Blood, leucocyte, and semen samples were subjected to whole-genome sequencing, resulting in mtDNA and nuclear DNA to estimate mtDNA CN. Findings revealed that 11% to 31% of the variation in mtDNA CN is under genetic control. Non-genetic effects of tissue type, age, and sex were significantly associated with mtDNA CN. Semen samples had the lowest mtDNA CN, followed by blood and leucocyte samples. Younger and older ages were associated with a greater mtDNA CN than intermediate ages. Females had greater mtDNA CN than males. Heterosis and breed composition were not significantly associated with mtDNA CN. These results suggest that mtDNA CN is heritable and would respond favorably to genetic selection.

Read the full article in the Journal of Animal Science.