Sunday , April 11 2021

Only DNA from mothers can come from fathers



Fibroblasts or connective tissue cells. Blue nucleus, green mitochondria.
Picture: NICHD (Flickr)

You've probably learned two things about mitochondria in high school biology. First, the cell's power plants. Second, you can only get them from your mother. But a new study seems to cloud this second point.

A team of US, Chinese and Taiwanese researchers have identified three irrelevant families whose mitochondria are members of both parents. While this discovery can reconsider the debate about the nature of mitochondrial DNA, researchers hope that they will open new pathways for the treatment of the disease.

The story began when a four-year-old patient suffering from fatigue and muscle ache was sent to physician-scientist Taosheng Huang at the Cincinnati Children's Hospital Medical Center. Others suggested that the child was a sign of a mitochondrial disorder, so Huang listed and analyzed the child's mitochondrial DNA and found an abnormally high lu heteroplasmic bir that appeared to contain different genes of different mitochondria.

Mystified outlined the mitochondrial DNA of other family members of the child, including sisters, parents, grandparents and siblings of parents and grandparents. It turned out that the child had taken strange mitochondria from his mother, who, as expected, shares his high-level heteroplasm. However, further analysis revealed that her mother, grandfather and two great aunts inherited mitochondrial DNA from both parents.

Huang also reached other laboratories to search for families with members with similarly high levels of heteroplasm. Two people with similar models found some individuals inherited mitochondrial DNA from their parents; these mothers would then pass on to their children. And to further remove the suspicion, Huang ensured that he took independent blood samples to the Baylor School of Medicine and ordered the three families to mitochondrial DNA on his own. Their results confirmed Huang.

These results are naturally provocative, because a number of other attempts have been made to show mitochondrial DNA, which is transmitted from parents to parents as well as from the father to the child. Gizmodo has reached several external sources for comment and updates the feed when we return. Since the egg destroys the mitochondria of the sperm after the fertilization, it is not clear how the male mitochondria will turn it into an egg. The new study published in the Proceedings of the National Academy of Sciences argues that perhaps the mutation eliminates the ability to screen eggs mitochondria.

This study does not have a great effect on the evolutionary time scales that the mother's heritage is zaman absolutely dominant evrim and that the authors write an exception to a rule. But Huang was more interested in what the outcome meant to treat the disease.

You may be familiar with another project where researchers produce a baby from three parents – an egg from a donor, a nucleus from a mother, and sperm from a father. This was to prevent her from going through the Leigh syndrome. . This is a very complicated and costly procedure,. Huang said of Gizmodo. Perhaps, if they can find the mechanism to transfer the father's mitochondria, they can offer these options without a three-parent procedure.

Even in the case of the best accepted facts, it seems difficult to find strict rules in biology.

[PNAS]

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