Transfer of mitochondrial and chloroplast DNA to the nucleus

From Wikipedia, the free encyclopedia
Jump to: navigation, search

As a logical conclusion of the endosymbiotic theory, since modern-day mitochondrial and chloroplast genomes do not contain a full set of housekeeping genes, and lack many that other descendants of their speculative ancestors share, there must have been a loss of genes. However, some of these genes likely migrated to the nucleus, where analogues of these genes are now found.

Puzzle[edit]

It is not clear why only a subset of genes have been transferred, when such gene transfer is known to be rapid - on a similar timescale as mutation. Mitochondria and chloroplasts perform redox reactions, which are known to be considerably mutagenic. Such mutagenicity would encourage migration of genes away from the organelles to the nucleus.

Proposed explanations[edit]

References[edit]

  1. ^ a b Daley,D.O. and Whelan,J. (2005) Why genes persist in organelle genomes. Genome Biol., 6, 110.
  2. ^ Allen,J.F. (2003) The function of genomes in bioenergetic organelles. Philos. Trans. R. Soc. Lond., B, Biol. Sci., 358, 19–38.

Allen, J. F., Puthiyaveetil, S., Ström, J. & Allen, C. A. 2005. BioEssays 27:426–435.

de Grey, A. D. N. J. 2005. Forces maintaining organellar genomes: is any as strong as genetic code disparity or hydrophobicity? BioEssays 27:436–446.

See also[edit]