This discovery has been a shock for those fields that are based on this “dogma” of biology, such as the study of human evolution or the development of nuclear transfer techniques
Until very recently, it was thought that mitochondria, small cellular components responsible for maintaining the cell’s energy requirements, were inherited exclusively though the maternal line, that is, only the mother’s mitochondria remain after fertilization. Nevertheless, a recent article published in PNAS has reported 17 cases of biparental inheritance of mitochondria in humans; in other words, 17 people have mitochondria not only from their mother, but also from their father.
A scientific dogma questioned could affect various major lines of investigation included evolution
Although further research is needed to determine its causes, it is thought that it may be due to a mutation in the nuclear DNA. This discovery has been a shock for those fields that are based on this “dogma” of biology, such as the study of human evolution or the development of nuclear transfer techniques (see HERE).
Thus, mitochondrial lineages have been studied to infer conclusions with respect to the common ancestral origins between different populations. However, this discovery implies that the genealogical data obtained in the studies could be incorrect, although it is likely that they are simply exceptional cases.
On the other hand, it raises an interesting possibility. If the nuclear genes responsible for regulating mitochondrial inheritance are determined, these could be modified to favor the inheritance of paternal mitochondria in cases in which the mother has a serious mitochondrial disease, perhaps dispensing with mitochondrial replacement techniques, which present unquestionable ethical problems (see HERE ).
Some ethical drawbacks
Be that as it may, alteration of the genome in the germ line, which is what this alternative would require, also has serious associated ethical drawbacks (see HERE ). In fact, the main ethical issues are shared between two possibilities
1. Human embryos would be produced in vitro and many of them destroyed.
2. In both cases, they would be germ line alterations, so that any uncontrolled effect could be very serious for the individual, whose development has yet to take place. Moreover, the changes would be transmitted to descendants, thus exacerbating the risks. A risk-benefit assessment from a medical point of view would also be warranted.