Phylogenetic analyses suggest lateral gene transfer from the mitochondrion to the apicoplast.
Apicomplexan protozoa contain a single mitochondrion and a multimembranous plastid-like organelle termed apicoplast. The size of the apicomplexan plastid genome is extremely small (35 kb) thus offering a limited number of genes for phylogenetic analysis. Moreover, the sequences of apicoplast genes are highly adenosine+thymidine-rich and rapidly evolving. Due to these facts, phylogenetic analyses based on different genes or the structure of the ribosomal operon show conflicting results and the evolutionary history of this exciting organelle remains unclear. Although it is evident that the apicoplast and its genome is plastid-derived, our detailed phylogenetic analysis of amino acid and nucleotide sequences of selected apicoplast ribosomal protein genes rpl2, rpl14 and rps12 show their possible mitochondrial origin. The affinity of apicoplast ribosomal proteins to their mitochondrial homologs is very stable and well supported. Based on our results we propose that apicoplasts might contain both plastid and mitochondrial genes, thus constituting a hybrid assembly.
Oborník
Miroslav
M
Institute of Parasitology, Czech Academy of Sciences, Branisovská 31, 370 05, Ceské Budejovice, Czech Republic. obornik@paru.cas.cz
Van de Peer
Yves
Y
Hypsa
Václav
V
Frickey
Tancred
T
Slapeta
Jan R
JR
Meyer
Axel
A
Lukes
Julius
J
D000818:Animals; D001482:Base Composition; D004272:DNA, Mitochondrial / Q000235:genetics*; D016054:DNA, Protozoan / Q000235:genetics; D019143:Evolution, Molecular; D017125:Genes, Protozoan / Q000235:genetics; D015388:Organelles / Q000235:genetics*; D010802:Phylogeny; D010963:Plasmodium falciparum / Q000235:genetics; D018087:Plastids / Q000235:genetics; D015800:Protozoan Proteins / Q000235:genetics; D012269:Ribosomal Proteins / Q000235:genetics; D014122:Toxoplasma / Q000235:genetics
D004272:DNA, Mitochondrial; D016054:DNA, Protozoan; D015800:Protozoan Proteins; D012269:Ribosomal Proteins; C041174:ribosomal protein L14; C029466:ribosomal protein L2; C034212:ribosomal protein S12