“…There are two steps in protecting individuals against the transmission of deleterious mutations to the progeny. One is the elimination of damaged mitochondria to the zygote in a mechanism, which is called bottleneck [ 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 ]; the second is lowering mitochondrial activity in the germ-line cells in order to minimize the damage to mitochondrial DNA by the reactive oxygen species (ROS) that are produced during oxidative phosphorylation [ 21 , 66 ]. ROS generate mutations in the mitochondrial DNA (mtDNA) that deteriorates the functions of these organelles [ 25 , 67 , 68 , 70 ] and, in addition, is considered to be the main source of aging [ 37 , 71 , 72 , 73 , 74 , 75 , 76 ].…”