Molecular Medicine and Diagnostics

Biography

Biography: Carlos Fernando Prada Quiroga

Abstract

Mitochondrial genome plays a variety of important roles, including the generation of ATP through respiration and oxidative phosphorylation (OXPHOS), production of reactive oxygen species (ROS), and initiation and execution of apoptosis. Therefore, variation in these genes can directly influence metabolic performance. The mitochondrial genome presents a gene structure relatively stable through the evolution of species with a relatively low rate of gene rearrangements compared to the nuclear genome. The recent increase in the number of sequenced mitochondrial genomes of hundreds of species, it has become clear that some groups of species the gene order is more conserved than in other groups. For example, mammals and birds have relatively stable gene orders, while in amphibians, reptiles and fish rearrangements are more common. Recent studies have found that the mammalian mitochondrial genome has a higher rate of rearrangements than expected. 244 mitochondrial events were identified: Inversions, deletions and non-homologous regions (non-HR: less than 10% nucleotide identity). Inversions were found at a frequency of 84.0 % (205/244). These inversions, classified as microinversions (<1Kb) are recurrent in tRNAs genes; deletion are detected on D-loop region and tRNAs; and non-HR located on control region. Based on the breakpoints (BP) of mitochondrial inversions, there were postulated fourteen fragile regions in the human mitochondrial genome. Over 250 pathogenic human mtDNA mutations have been characterized to show the cause a wide variety of diseases with heterogeneity of phenotypes and a variable age of onset. Most of deletions and duplications BP reported in the human mitochondrial genome match with the fragile regions previously postulated. These findings could indicate the important role of tRNA in the origin of rearrangements in the human mitochondrial genome and in mammals in general.