The complete mitochondrial genome of Aphelenchoides besseyi (Nematoda: Aphelenchoididae), the first sequenced representative of the subfamily Aphelenchoidinae

The complete mitochondrial genome (mitogenome) of Aphelenchoides besseyi is 16 216 bp in size and has the typical organisation of nematode mitogenomes of Chromadorea, including 12 protein-coding genes (PCGs), two rRNA genes, 22 tRNA genes and the AT-rich non-coding region. The nucleotide composition of the mitogenome of A. besseyi is AT-biased (80.0%) and the AT skew is -0.289. The most common start codon for A. besseyi is ATT. The nad3 and nad4L genes have an incomplete stop codon consisting of just a T and the other PCGs stop with the full stop codons. All the tRNA genes display a non-typical cloverleaf structure of mitochondrial tRNA. The AT-rich non-coding region contains ten tandem repeat units with four different regions. Phylogenetic analysis based on concatenated amino acid sequences of 12 protein-coding genes showed that three Tylenchomorpha species, including A. besseyi, Bursaphelenchus mucronatus and B. xylophilus from the superfamily Aphelenchoidea, are placed within a well-supported monophyletic clade, but far from the other six Tylenchomorpha species Meloidogyne chitwoodi, M. graminicola, M. incognita, Pratylenchus vulnus, Heterodera glycines and Radopholus similis of Tylenchoidea. This phylogeny suggests that Aphelenchoides has a close relative relationship with Bursaphelenchus and that the Tylenchomorpha is not monophyletic.