The complete mitochondrial genome of the fire coral-inhabiting barnacle Megabalanus ajax (Sessilia: Balanidae): gene rearrangements and atypical gene content

Abstract

The complete mitochondrial genome of Megabalanus ajax Darwin, 1854 (Sessilia: Balanidae) is reported. Compared to typical gene content of metazoan mitochondrial genomes, duplication of one tRNA gene (trnL₂) and absence of another tRNA gene (trnS₁) are identified in M. ajax mitochondrial genome. There is a replacement of one tRNA (trnS₁) by another tRNA (trnL₂) in M. ajax mitochondrial genome compared to Megabalanus volcano mitochondrial genome. Inversion of a six-gene block (trnP-nd4L-nd4-trnH-nd5-trnF) is found between M. ajax/M. volcano and Tetraclita japonica mitochondrial genomes. With reference to the pancrustacean mitochondrial ground pattern, there is an inversion of a large gene block from the light strand to heavy strand in the two Megabalanus mitochondrial genomes, including three PCGs and two tRNAs (nd4L-nd4-trnH-nd5-trnF). Furthermore, four tRNAs (trnA, trnE, trnQ and trnC) exhibit translocation, while translocation and inversion occur in three tRNAs (trnP, trnY and trnK).

• Gene duplication
• gene rearrangement
• Maxillopoda
• mitochondrial genome
• Sessilia

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper. This work was supported by funding from the Center of Excellence for the Oceans, National Taiwan Ocean University, the Hong Kong Scholars Program (XJ2012056) and the Career Development Award in Academia Sinica, Taiwan (AS-98-CDA-L15) and a grant from the National Science Council, Taiwan (NSC-99-2621-B-001-007-MY3), and a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions.