Comparative analysis of mitochondrial genome sequences of root-knot nematodes

GARCIA, LE; SANCHEZ PUERTA, MV

La Serena

Congreso; XLV ONTA Meeting; 2013

ONTA

Mitochondria are endosymbiotic bacteria in charge of oxidative phosphorylation and other essential biochemical functions within the eukaryotic cell. The mitochondrial genome (mtDNA) is typically non-recombining and presents regions that evolve at markedly different rates. As a consequence, different portions of the mtDNA are well suited to differentiating morphologically similar species. We characterized mitochondrial genome sequences from two species of root-knot nematodes: Meloidogyne incognita (~18 kb) and M. hapla (~16 kb). Mitochondrial sequences were mined from complete genome projects in Genbank and were analyzed regarding protein coding genes, rRNAs and tRNAs. We studied the codon usage, substitution rates and evolution of seven genes for each species; cox1, cox2, cytb, nd1, nd3, nd4 and nd5 from M. hapla, and cox1, cox2, cox3, cytb,nd1, nd3, and nd4 from M. incognita. The nucleotide composition of the partial mtDNAs was A/T-biased, with an overall A/T content of 80,3% in M. hapla and 81,8% in M. incognita. The similarity between coding regions of M. incognita and M. hapla was 72-82%. We also identified indels within coding sequences. These findings are valuable to develop new molecular markers for taxonomic purposes at the species level.