Hope you don’t mind a real question instead of the stupid stuff teh idiots usually send you.
This morning we had a lecture by Salvatore DiMauro, M.D. from columbia university (he is neurolog/neuromuscular mainly mitochondrial diseases) about mitochondrial diseases.
Any evidence for ERV’s in the mitochondrial genome?
Short answer– No. Mitochondria have a different kind of integrated virus…
Long answer– There are two ways mitochondria could get an ERV.
Retrovirus infected bacteria was the original endosymbiont 1.7-2 billion years ago– Not likely. We dont have any evidence retroviruses have/do infect bacteria.
Retrovirus infected mitochondria post endosymbiosis– Not likely. A ‘naked’ retrovirus that has infected a cell has no way of getting into a mitochondria. Especially the kind of retroviruses that tend to form ERVs– They need the nuclear envelope to dissolve to gain access to nuclear DNA. Their cDNA would have a lot of trouble crossing mitochondrial membranes, if it was even misdirected towards the mitochondria instead of the nucleus in the first place. And, while there is some suggestion that plant mitochondria can take up double-stranded DNA, what they are capable of sucking up is a fraction of the size of the smallest retrovirus.
But this doesnt mean mitochondrial genomes are virus-free! Mitochondria werent always a part of us. They used to be bacteria. And bacteria have PHAGE!!
You know how human genomes can commandeer ERV proteins and promoters for stuff? Mitochondria have done the same thing… with phage genes! Phages are DNA viruses that infect bacteria. But they insert, permanently, into genomes like retroviruses. So bits and pieces of phage genome in an endosymbiont 1.7-2 billion years ago have turned into mitochondrial genes!