Gene fragmentation: a key to mitochondrial genome evolution in Euglenozoa?

0364837 - BC 2012 RIV DE eng J - Journal Article
Flegontov, Pavel - Gray, M.W. - Burger, G. - Lukeš, Julius
Gene fragmentation: a key to mitochondrial genome evolution in Euglenozoa?
Current Genetics. Roč. 57, č. 4 (2011), 225-232. ISSN 0172-8083. E-ISSN 1432-0983
Institutional research plan: CEZ:AV0Z60220518
Keywords : Euglena * Diplonema * Mitochondrial genome * RNA editing * Constructive neutral evolution
Subject RIV: EB - Genetics ; Molecular Biology
Impact factor: 2.556, year: 2011

Gene fragmentation is a striking feature of both euglenid and diplonemid mtDNAs. To rationalize the emergence of these highly divergent mtDNA types and the existence of insertion/deletion RNA editing (in kinetoplastids) and trans-splicing (in diplonemids), we propose that in the mitochondrion of the common evolutionary ancestor of Euglenozoa, small expressed gene fragments promoted a rampant neutral evolutionary pathway. Interactions between small antisense transcripts of these gene fragments and full-length transcripts, assisted by RNA-processing enzymes, permitted the emergence of RNA editing and/or trans-splicing activities, allowing the system to tolerate indel mutations and further gene fragmentation, respectively, and leading to accumulation of additional mutations. In this way, dramatically different mitochondrial genome structures and RNA-processing machineries were able to evolve.
Permanent Link: http://hdl.handle.net/11104/0200214