The Complete Mitochondrial Genome Sequence of the Planthopper, Sivaloka damnosus

The complete mitochondrial genome (mitogenome) sequence was determined from the plant hopper, Sivaloka damnosus Chow and Lu (Hemiptera: Issidae), a representative of the insect family Issidae. The genome is a circular molecule of 15,287 bp with a total A+T content of 76.5%. The gene content, order, and structure are identical to that in Drosophila melanogaster, which is considered ancestral for insects. All 13 protein-coding genes of the S. damnosus mitogenome have a putative inframe ATR methionine or ATT isoleucine codons as start signals. The usual termination codons (TAA and TAG) were found in 11 protein-coding genes. However, atp6, and nad4 have incomplete termination codons. All tRNAs show stable canonical clover-leaf structures similar to other insect mitochondrial tRNAs, except for tRNASer(AGN), which has a reduced DHU arm. The A+T-rich region or putative control region includes two extensive repeat regions. The first repeat region is composed of two sets of complicated repeat units, and these repetitive sequences are arranged alternately; the second contains ten 20 bp tandemly repetitive sequences. In the phylogenetic analyses based on protein-coding genes, Cicadomorpha is a sister to Fulgoromorpha+Sternorrhyncha, and Heteroptera is a sister to all other Hemiptera

The complete nucleotide sequence of the mitochondrial genome of Bactrocera minax (Diptera: Tephritidae)

The complete 16,043 bp mitochondrial genome (mitogenome) of Bactrocera minax (Diptera: Tephritidae) has been sequenced. The genome encodes 37 genes usually found in insect mitogenomes. The mitogenome information for B. minax was compared to the homologous sequences of Bactrocera oleae, Bactrocera tryoni, Bactrocera philippinensis, Bactrocera carambolae, Bactrocera papayae, Bactrocera dorsalis, Bactrocera correcta, Bactrocera cucurbitae and Ceratitis capitata. The analysis indicated the structure and organization are typical of, and similar to, the nine closely related species mentioned above, although it contains the lowest genome-wide A+T content (67.3%). Four short intergenic spacers with a high degree of conservation among the nine tephritid species mentioned above and B. minax were observed, which also have clear counterparts in the control regions (CRs). Correlation analysis among these ten tephritid species revealed close positive correlation between the A+T content of zero-fold degenerate sites (P0FD), the ratio of nucleotide substitution frequency at P0FD sites to all degenerate sites (zero-fold degenerate sites, two-fold degenerate sites and four-fold degenerate sites) and amino acid sequence distance (ASD) were found. Further, significant positive correlation was observed between the A+T content of four-fold degenerate sites (P 4FD) and the ratio of nucleotide substitution frequency at P 4FD sites to all degenerate sites; however, we found significant negative correlation between ASD and the A+T content of P4FD, and the ratio of nucleotide substitution frequency at P4FD sites to all degenerate sites. A higher nucleotide substitution frequency at non-synonymous sites compared to synonymous sites was observed in nad4, the first time that has been observed in an insect mitogenome. A poly(T) stretch at the 5′ end of the CR followed by a [TA(A)]n-like stretch was also found. In addition, a highly conserved G+A-rich sequence block was observed in front of the poly(T) stretch among the ten tephritid species and two tandem repeats were present in the CR. © 2014 Zhang et al