At the end of 2018 has been described a unique case of the mixed inheritance of mitochondria from the father and from the mother. In a new article in Nature Communications suggests an alternative explanation for this phenomenon. According to the authors, the father’s DNA found by the previous researchers could not be located in the mitochondria and in the nuclear genome. A giant insert of mitochondrial DNA (mtDNA) creates the illusion of the presence of the paternal mitochondria, whereas in fact they are not.
In past work , where it was inherited mitochondria was determined by the DNA sequences. In several samples of DNA coincided with the sequence of maternal mitochondrial and paternal sequences, from which the researchers concluded that the mitochondria in the cells of these people came from both parents. This unexpected finding contradicts the dogma, talking about what people these organelles are always passed only from the mother. The coexistence of mitochondria from two sources is disadvantageous from an evolutionary point of view, such cases are rare in the animal world and are often accompanied by pathologies.
Wei Wei (Wei Wei) and his colleagues from the University of Cambridge analyzed 11035 triples of genomes of mother-father-child, tsakonian in the framework of the project on rare diseases, and found, in addition to the three already found, seven more cases of the coexistence of maternal and paternal mtDNA in a child. In the initial stages of DNA analysis, there were even more, but the researchers focused only on samples with “complete” paternal DNA. They identified the areas in which Otsuka DNA different from the mother, and took in the analysis only those children who had more than 95 percent of such unique DNA regions.