The Complete Mitochondrial Genome and Novel Gene Arrangement of the Unique-Headed Bug Stenopirates sp. (Hemiptera: Enicocephalidae)

Abstract

Many of true bugs are important insect pests to cultivated crops and some are important vectors of human diseases, but few cladistic analyses have addressed relationships among the seven infraorders of Heteroptera. The Enicocephalomorpha and Nepomorpha are consider the basal groups of Heteroptera, but the basal-most lineage remains unresolved. Here we report the mitochondrial genome of the unique-headed bug Stenopirates sp., the first mitochondrial genome sequenced from Enicocephalomorpha. The Stenopirates sp. mitochondrial genome is a typical circular DNA molecule of 15, 384 bp in length, and contains 37 genes and a large non-coding fragment. The gene order differs substantially from other known insect mitochondrial genomes, with rearrangements of both tRNA genes and protein-coding genes. The overall AT content (82.5%) of Stenopirates sp. is the highest among all the known heteropteran mitochondrial genomes. The strand bias is consistent with other true bugs with negative GC-skew and positive AT-skew for the J-strand. The heteropteran mitochondrial atp8 exhibits the highest evolutionary rate, whereas cox1 appears to have the lowest rate. Furthermore, a negative correlation was observed between the variation of nucleotide substitutions and the GC content of each protein-coding gene. A microsatellite was identified in the putative control region. Finally, phylogenetic reconstruction suggests that Enicocephalomorpha is the sister group to all the remaining Heteroptera.

Comparative mitogenomic analysis of the superfamily Pentatomoidea (Insecta: Hemiptera: Heteroptera) and phylogenetic implications

“…4, Additional file 7). This is an unusual phenomenon, but has also been observed in the DHU arm in other true bugs [19, 24, 30–32]. In U. quadrinotata and E. cupreus , trnV has an extremely short (only 1 bp) DHU stem, suggesting that this tRNA may have lost the DHU arm, as has been observed in other pentatomoid species (Fig.…”

The Complete Mitochondrial Genome of the Stalk-Eyed Bug Chauliops fallax Scott, and the Monophyly of Malcidae (Hemiptera: Heteroptera)

“…In some arthropods mt-genomes, the control region was reported to have one to four of these four different motifs: tandem repeats, poly-thymine (poly-T) sequence, a subregion of even higher AT richness, and a stem-loop structure [39]. The control region of C. fallax contained all these four motifs and could be divided into five parts (Figure 7A): (1) at the 5′-end of the control region is a 7 bp poly-C structure, which was also found in other insects [20], [25]; (2) a 8 bp poly-T stretch and a microsatellite-like region ((TA) 4 (GATATA) 2 ); (3) a 35 bp region heavily biased toward A+T (91.4%); (4) a 460 bp region contained four tandem repeats including three (I–III) 122 bp repeat units and a partial copy of the repeat (IV) 94 bp, which were identified by tandem repeats finder server [40]; (5) a potential stem-loop secondary structure was found at the end of control region, however, without ‘TATA’ sequence existed at the 5′ end and ‘G(A)nT’ at the 3′ end (Figure 7B). In the second region, the poly-T stretch may play a role in the control of transcriptional or may be the site of replication initiation [41].…”

“…The secondary structure of the helix H1835 is similar to that proposed for Drosophila melanogaster [15], Apis mellifera [18] and Ruspolia dubia [19], which are different with the structure of some true bugs proposed by Li et al . [20]. In domain V, most helices are highly conserved in secondary structure, with the exception of H2077 and H2347.…”

Comparative Mitogenomic Analysis of Damsel Bugs Representing Three Tribes in the Family Nabidae (Insecta: Hemiptera)

“…Gene cox1 and nad1 has been found to employ TTG or GTG as a start codon in some species of Hemiptera, Hymenoptera, Coleoptera and Lepidoptera, thus minimizing intergenic spacing and avoiding overlaps with adjacent genes [18]–[20]. We discovered TTG start codons in cox1 gene for most sequenced damsel bugs and GTG start codon in nad1 gene for G. humeralis (Table S1).…”