Mitochondrial DNA
Mitochondrial DNA was discovered in the 1960s by Margit M. K. Nass and Sylvan Nass by electron microscopy as DNase-sensitive threads inside mitochondria, and by Ellen Haslbrunner, Hans Tuppy and Gottfried Schatz by biochemical assays on highly purified mitochondrial fractions.
Paternal mtDNA transmission
The mixing of maternal and paternal mtDNA was thought to have been found in chimpanzees in 1999 and in humans in 1999 and 2018, resulting this last finding quite impressive, as biparental mtDNA was observed in subsequent generations in three different familias, leading to the conclusion that, although the maternal transmission dogma remains strong, there is evidence that paternal transmission do exist and there is a probably a mechanism which, if elucidated, can be a new tool in reproductive field, for example, avoiding the mitochondrial replacement therapy, and just using this mechanism so that the offspring inherit the paternal mitochondria. However, there has been only a single documented case of 90% human paternal mitochondrial DNA transmission.