Mitochondrial DNA

[MrMistery]

Well, mitochondria are not alive to begin with.
They have antigenes that will not be recognised as self because they are never supposed to be on the outside of cells. while inside the cell they never come into contact with phagocytic WBC.

About isolating them and keeping them "alive". Tricky. in order to give a mitochondrium a desired protein, you would need to first bind it to a shuttle protein from the HSP family, which would deliver it to the mitochondrium. if you just give them the mature protein(with no signal sequence) the mitochondrium won't take it up.

[genovese]

Thank you for your replies.

If we could re-introduce the missing bits of DNA into mitochondria, would we then get back to a fully independent bacterium, and are those missing DNA sequences to be found somewhere in our nuclear DNA?

[genovese]

Since the genetic code of mitochondria is slightly different to the Universal Code, how can our genes code for the right proteins that it needs?

[MrMistery]

Thank you for your replies.

If we could re-introduce the missing bits of DNA into mitochondria, would we then get back to a fully independent bacterium, and are those missing DNA sequences to be found somewhere in our nuclear DNA?

yes. genes have steadily migrated from mitochondria to the nucleus.

Since the genetic code of mitochondria is slightly different to the Universal Code, how can our genes code for the right proteins that it needs?

that is why gene migration from the mit to the nucleus is such a rare phenomenon(one of the reasons). But it is possible because mRNA is NEVER imported into the mitochondria(asides from using a slightly different genetic code, the signals for beginning and end of transcription are different.). Ready-made proteins are imported into the mitochondria, and because of that, it does not really matter what genetic code was used to translate them.

[genovese]

I know that mitochondria can be extracted from tissues, stored at low temperatures and then used for laboratory experimentation. Has anyone then tried to re-insert the mitochnodria back into living human cells to see if they then return to fully functioning units?

The purpose of my question is that many intracellular parasites can live outside their host in some sort of dormant phase (eg viruses) to become “active” once they re-infect. Viruses have been classifed but mitochondria have not. If functioning mitochondria could be re-introduced into cells would this entitled them to being classified as a species in their own right?