title: The mitochondrial genome of the predatory mite Metaseiulus occidentalis (Arthropoda: Chelicerata: Acari: Phytoseiidae) is unexpectedly large and contains several novel features.
abstract: The complete mitochondrial genome of the phytoseiid Metaseiulus occidentalis (Arthropoda: Chelicerata: Acari: Phytoseiidae) has been sequenced. It is 24,961 bp in length and contains a 14,695-bp unique region, a 345-bp triplicated region, and a 9921-bp duplicated region, in that order. The A+T content of the unique region is 76.9% and contains 11 protein coding (COI-III; ATP6-8; CytB; ND1, 2, 4, 5 and 4L), two ribosomal RNA (srRNA and lrRNA), 22 transfer RNA (tRNA) genes, and two copies of D-loop control sequence. Two genes (ND3 and 6) appear to be missing, but there is a large intergenic spacer (390 bp) present, which could contain ND3 if a different codon usage is employed. The gene order is completely different from the pattern in all other known chelicerates, including the horseshoe crab Limulus polyphemus [Lavrov et al., Mol. Biol. Evol., 2000; 17:813-824]. All the inferred tRNA genes are missing the TPsiC arm, but this arm has fused with the variable arm to generate a TV replacement loop. The duplicated region (9921 bp) contains 18 genes in the same order as in the unique region from CytB to tRNA-His, plus one copy of D-loop control sequence (311 bp) and a partial tRNA-Leu2 sequence (34 bp). The small triplicated region (345 bp) contains a D-loop control sequence (311 bp) and a partial tRNA-Leu2 sequence (34 bp). Because of these anomalies, amplifying sequences posed technical difficulties, but were accomplished by using a primer-walking strategy and increasing the AT content to 75% in the high-fidelity PCR dNTP mix. This is the first phytoseiid mitochondrial genome to be completely sequenced and the largest (25 kb) detected from the Chelicerata.
authors.affiliation: Department of Entomology & Nematology, PO Box 110620, University of Florida, Gainesville, FL 32611, USA. ajey@ifas.ufl.edu
authors.forename: Ayyamperumal
authors.initials: A
authors.lastname: Jeyaprakash
authors.forename: Marjorie A
authors.initials: MA
authors.lastname: Hoy
mesh_terms: D000818:Animals; D001482:Base Composition; D001483:Base Sequence; D021901:DNA, Intergenic / Q000235:genetics; D004272:DNA, Mitochondrial / Q000737:chemistry / Q000235:genetics*; D023061:Gene Order; D008925:Mites / Q000235:genetics*; D024101:Mitochondrial Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D012335:RNA, Ribosomal / Q000235:genetics; D012343:RNA, Transfer / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D021901:DNA, Intergenic; D004272:DNA, Mitochondrial; D024101:Mitochondrial Proteins; D012335:RNA, Ribosomal; D012343:RNA, Transfer