Microheterogeneity and coevolution: an examination of rDNA sequence characteristics in Neoparamoeba pemaquidensis and its prokinetoplastid endosymbiont.
Neoparamoeba pemaquidensis, the etiological agent of amoebic gill disease, has shown surprising sequence variability among different copies of the 18S ribosomal RNA gene within an isolate. This intra-genomic microheterogeneity was confirmed and extended to an analysis of the internal transcribed spacer (ITS) region. High levels of intra-genomic nucleotide diversity (Pi=0.0201-0.0313) were found among sequenced ITS regions from individual host amoeba isolates. In contrast, the ITS region of its endosymbiont revealed significantly lower levels of intra-genomic nucleotide diversity (Pi=0.0028-0.0056) compared with the host N. pemaquidensis. Phylogenetic and ParaFit coevolution analyses involving N. pemaquidensis isolates and their respective endosymbionts confirmed a significant coevolutionary relationship between the two protists. The observation of non-shared microheterogeneity and coevolution emphasizes the complexity of the interactions between N. pemaquidensis and its obligate endosymbiont.
Caraguel
Charles G B
CG
AVC Lobster Science Centre, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Prince Edward Island, C1A 4P3, Canada.
O'Kelly
Charles J
CJ
Legendre
Pierre
P
Frasca
Salvatore
S
Gast
Rebecca J
RJ
Després
Béatrice M
BM
Cawthorn
Richard J
RJ
Greenwood
Spencer J
SJ
D000818:Animals; D004275:DNA, Ribosomal / Q000235:genetics*; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D019143:Evolution, Molecular; D014644:Genetic Variation; D016840:Lobosea / Q000145:classification / Q000235:genetics*; D008969:Molecular Sequence Data; D010802:Phylogeny; D012340:RNA, Ribosomal, 5.8S / Q000235:genetics; D017422:Sequence Analysis, DNA
D004275:DNA, Ribosomal; D021903:DNA, Ribosomal Spacer; D012340:RNA, Ribosomal, 5.8S