Abstract
The mitochondrial genomes of higher plants are larger and more complex than those of other organisms. The fine structure of the mitochondrial genomes of higher plants is still not well characterized.
To determine the size of the DNA molecules which constitute mitochondrial genome of Arabidopsis thaliana, we tried to visualize mitochondrial DNA (mtDNA) by using YOYO-1. After the isolation of mitochondria from Arabidopsis thaliana by Percoll density gradients centrifugation, we put the mitochondria on a slide glass, burst them, and stained extended mtDNA fiber by YOYO-1. We observed circular and linear mtDNA. A standard curve of size (kbp)-to-μm was made with bacterial artificial chromosomes. We estimated the size of DNA (in kbp) from μm using this equation. The sizes of mtDNA varied. Surprisingly, we found the DNA molecule that was about twice as long as the entire mitochondrial genome of Arabidopsis thaliana.
