3 ms·

Is this ecDNA of similar size to the circular DNA of the mitochondria? This seems like a reversion of the form of DNA to a prokaryotic state.

• anonymouskimmer 4y ago
  It ranges from much smaller to much larger than mitochondrial genomes. https://en.wikipedia.org/wiki/Extrachromosomal_circular_DNA https://en.wikipedia.org/wiki/Extrachromosomal_circular_DNA > Extrachromosomal circular DNA is derived from chromosomal DNA, can range in size from 50 base pairs to several mega-base pairs in length, and can encode regulatory elements and full-length genes. eccDNA has been observed in various eukaryotic species[2][3][4][5][6][7][8] and it is proposed to be a byproduct of programmed DNA recombination events, such as V(D)J recombination. There are basically two ways to keep DNA from degrading in the cell: protect the ends with special proteins or DNA structures, or make it so that there are no ends to protect by having the DNA be circular. https://en.wikipedia.org/wiki/Linear_chromosome https://en.wikipedia.org/wiki/Linear_chromosome > Linear chromosomes are not limited to eukaryotic organisms; some prokaryotic organisms have linear chromosomes as well. > a good number of eukaryotic species do harbor linear mtDNA <mitochondrial DNA>, some even broken into multiple molecules
• robwwilliams 4y ago
  Highly variable. In cancers they can be much larger. Mitochondrial circular DNA is about 16,600 basepairs. In comparison, in the paper below one example of a cancer-driven ecDNA is 1,260,000 basepairs (EGFRvIII). ecDNA were originally detected using cytogenetic light microscopic methods, hence the original bias toward large size. Wikipedia article: https://en.wikipedia.org/wiki/Extrachromosomal_DNA https://en.wikipedia.org/wiki/Extrachromosomal_DNA https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5334176/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5334176/