Nucleomorph
The strongly reduced additional cell nucleus in the complex plastids of the Cryptophyceae and Chlorarachniophyceae is called nucleomorph (sometimes also nucleomorph ) . In both groups of algae there is clear evidence that these rudimentary cell nuclei originate from secondary endosymbiosis . The nucleomorph is located between the two outer and the two inner envelope membranes of the plastid (although some of these membranes may have been lost in the course of evolution). The nucleomorph of the Cryptophyceae is related to the cell nuclei of the red algae , the nucleomorph of the Chlorarachniophyceae to those of the green algae . Both nucleomorph genomes contain only three small chromosomes . The majority of the genes that were originally contained in these genomes were transferred into the nucleus of the host cell in the course of evolution (endosybiotic gene transfer , EGT).
literature
- Archibald JM, Rogers MB, Toop M, Ishida Ki, Keeling PJ: Lateral gene transfer and the evolution of plastid-targeted proteins in the secondary plastid-containing alga Bigelowiella natans. Proceedings of the National Academy of Sciences of the USA 100.2003, 7678-7683.
- SE Douglas, S. Zauner, M. Fraunholz, M Beaton, S. Penny, LT Deng, X. Wu, M. Reith, T. Cavalier-Smith , UG. Maier: The highly reduced genome of an enslaved algal nucleus. Nature (London) 410. 2001: 1040-1041.
Individual evidence
- ↑ Veiko Krauß: Gene, random, selection , Springer-Verlag, 2014, ISBN 3642417558 , 9783642417559, on p. 91