Discussion in 'Fibromyalgia Main Forum' started by woofmom, Apr 28, 2006.

  1. woofmom

    woofmom New Member

    Chemicals can penetrate cell walls. A woman can then pass whatever genetic defect it caused to her yet to be born children.
  2. elliespad

    elliespad Member

    I took the following blurb from a website on Mitochondrial Inheritance. The third paragraph talks about mutations to mtDNA.

    In mammals, 99.99% of mitochondrial DNA (mtDNA) is inherited from the mother. This is because the sperm carries its mitochondria around a portion of its tail and has only about 100 mitochondria compared to 100,000 in the oocyte. As the cells develop, more and more of the mtDNA from males is diluted out. Hence less than one part in 104 or 0.01% of the mtDNA is paternal. This means that mutations of mtDNA can be passed from mother to child. It also has implications if one does cloning of mammals with the use of somatic cells. The nuclear DNA would be from the donor cell, but the mtDNA would be from the host cell. This is how Dolly the sheep was cloned.

    There is a Yeast strain, called "Petite" that have structurally abnormal mitochondria that are incapable of oxidative phosphorylation. These mitochondria have lost some or all of their DNA. Mitochondrial inheritance from yeast is biparental, and both parent cells contribute to the daughter cells when the haploid cells fuse. After meiosis and mitosis, there is random distribution of mitochondria to daughter cells. If the fusion is with yeast that are petite and yeast that are not, a certain percentage of the daughter cells will be "petite".

    Mutations in mammalian mtDNA do cause diseases, because there is such a short sequence and very heavy information content in the sequence. The next lecturer on mitochondria in this series will spend a great deal of time on the mitochondrial genome. Since each cell contains hundreds of mitochondria and thousands of copies of the genome, the effects of the mutated mitochondria may be diluted out. As expected, those tissues or organs most likely to be affected would be the ones most dependent on oxidative phosphorylation (ATP production). In young persons it might not be picked up because even a person with 15% normal mitochondria might have enough to be healthy. However, aging patients may show a more severe disease phenotype.

    To read the whole article, click on the link: