Email updates

Keep up to date with the latest news and content from BMC Genomics and BioMed Central.

Open Access Research article

The complete mitochondrial genome of the sexual oribatid mite Steganacarus magnus: genome rearrangements and loss of tRNAs

Katja Domes1*, Mark Maraun1, Stefan Scheu1 and Stephen L Cameron2

Author Affiliations

1 Technische Universität Darmstadt, Institut für Zoologie, Schnittspahnstr. 3, 64287 Darmstadt, Germany

2 Australian National Insect Collection and CSIRO Entomology, Black Mountain Laboratories, Clunies-Ross Street, Canberra, ACT 2601, Australia

For all author emails, please log on.

BMC Genomics 2008, 9:532  doi:10.1186/1471-2164-9-532

Published: 7 November 2008

Abstract

Background

Complete mitochondrial (mt) genomes and the gene rearrangements therein are increasingly used as molecular markers for investigating phylogenetic relationships, especially for elucidating deep splits. Contributing to the complete mt genomes of arthropods, especially Arachnida, available so far, we provide the first complete mt genome of a sarcoptiform mite species, the sexually reproducing oribatid mite Steganacarus magnus (Acari, Oribatida) which was determined by sequencing of long PCR products.

Results

The mt genome of S. magnus lacks 16 tRNAs, only those for leucine, histidine, proline, tryptophan, glutamine and serine are present. Within those tRNAs only tRNA-His and tRNA-Pro have kept their original position, the others are translocated. Furthermore, the mt genome of S. magnus consists of 13,818 bp and it is composed of 13 protein-coding genes and two genes for the ribosomal RNA subunits that are typically found in metazoan mt genomes. The gene order in S. magnus differs from the hypothetical ancestral chelicerate arrangement as conserved in Limulus polyphemus: instead of nad1-rrnL-rrnS-LNR-nad2 (tRNAs excluded) S. magnus is nad2-rrnL-nad1-rrnS-LNR. Phylogenetic analyses of a concatenated amino acid dataset of all mt protein-coding genes of 28 arthropod species suggest a sister-group relationship of sarcoptiform and prostigmatid mites (S. magnus and Leptotrombidium).

Conclusion

The mt gene arrangement of S. magnus differs from the hypothetical ground plan of arthropods and from that of other mites further contributing to the variety of mt gene arrangements found in Arachnida. The unexpected lack of tRNAs is enigmatic, probably showing that the loss of mt genes is an ongoing evolutionary process. For solving phylogenetic relationships of oribatid mite lineages and their position within Acari further complete mt genomes are needed.