The complete mitochondrial genome of Ochetellus glaber (Mayr, 1862) (Hymenoptera:Formicidae)

Complete Nucleotide Sequence of the Mitogenome of Tapinoma ibericum (Hymenoptera: Formicidae: Dolichoderinae), Gene Organization and Phylogenetics Implications for the Dolichoderinae Subfamily

The ant Tapinoma ibericum Santschi, 1925 is native to the Iberian Peninsula. This species, as well as other species from the Tapinoma nigerrimum complex, could form supercolonies that make these species potentially invasive and could give rise to pests. Recently a mature colony from this species has been found in the Isle of Wight (United Kingdom). Mitogenomes have been used to study the taxonomy, biogeography and genetics of species, improving the development of strategies against pest invasion. However, the number of available mitogenomes from the subfamily Dolichoderinae is still scarce and only two of these mitogenomes belong to Tapinoma species. Herein, the complete mitogenome of T. ibericum is presented in order to increase the molecular information of the genus. The T. ibericum mitogenome, retrieved by Next-Generation Sequencing data, is 15,715 bp in length. It contains the typical set of 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNAs and the A + T-rich control region. Comparisons of the T. ibericum mitogenome with other dolichoderine mitogenomes revealed the existence of four gene rearrangements in relation with the ancestral insect mitogenome. One of these rearrangements, involving the tRNA-Ile, tRNA-Gln and tRNA-Met genes, was found in most of the analyzed ant mitogenomes. Probably this rearrangement was an ancestral or plesiomorphic character in Formicidae. Interestingly, another rearrangement that affects to tRNA-Trp, tRNA-Cys and tRNA-Tyr genes was found only in Tapinoma species. This change could be a synapomorphic character for the genus Tapinoma, and could be used as a phylogenetic marker. Additionally, a phylogenetic analysis was performed using the protein-coding gene sequences from available Dolichoderinae mitogenomes, as well as mitogenomes from representative species from other Formicidae subfamilies. Results support the monophyletic nature of the genus Tapinoma placing it within the same clade as the rest of Dolichoderinae species.

Phylogenetic relationship and characterization of the complete mitochondrial genome of Camponotus japonicus (Hymenoptera: Formicoidea: Formicidae)

Camponotus japonicus Mayr, 1866 is a widespread and open-field formicine ant species in east Asia. In this study, we sequenced and analyzed the complete mitochondrial genome (mitogenome) of C. japonicus. This mitogenome was 16,422 bp long and encoded 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs) and two ribosomal RNA unit genes (rRNAs). Gene order was conserved and identical to most other previously sequenced Formicidae. All PCGs of C. japonicus have the conventional start codon for invertebrate mitochondrial PCGs (five ATT, four ATA and four ATG). All PCGs terminated with the stop codon TAA. The whole mitogenome exhibited heavy AT nucleotide bias (77.8%). Phylogenetic analysis positioned C. japonicus in a well-supported clade with C. atrox and C. concavus, and C. japonicus was more closely related to C. atrox than to C. concavus. Within Formicinae, the topology (Colobopsis + (Polyrhachis + Camponotus) + (Formica + (Nylanderia + Lasius) + (Anoplolepis + Acropyga))) was recovered.

The investigation of intraspecific characteristics and comparative analyses of the complete mitochondrial genome of Stegobium paniceum (Linnaeus, 1758) (Coleoptera: Ptinidae) assembled from public NGS raw reads of the black truffle, Tuber melanosporum

Due to the rapid development of NGS technologies, a huge amount of NGS raw reads have been accumulated in public repositories, such as the Short Read Archive of NCBI. We successfully rescued the complete mitochondrial genome of Stegobium paniceum, a drug store beetle, from public NGS raw reads of truffle generated from the whole genome project. The circular mitogenome of S. paniceum is 15,474 bp long including 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNAs, and a single large non-coding region of 803 bp. Intraspecific transfer RNAs structure and sequence variations were investigated and simple sequence repeats identified from three S. paniceum mitochondrial genomes were compared showing their diversities as fundamental data to utilize them in various aspects including developing efficient molecular markers in the family, Ptinidae. Phylogenetic analysis of 23 Bostrichoidea mitochondrial genomes presented better species identification based on phylogenetic analyses and the optimal options for constructing phylogenetic trees based on Bostrichoidea mitochondrial genomes. Our results present not only utilization of public NGS raw read sequences but also intraspecific features of S. paniceum mitochondrial genomes and comparative analysis of Bostrichoidea mitochondrial genomes in various aspects.

A Comparative Analyses of the Complete Mitochondrial Genomes of Fungal Endosymbionts in Sogatella furcifera, White-Backed Planthoppers

Sogatella furcifera Horvath, commonly known as the white-backed planthoppers (WBPH), is an important pest in East Asian rice fields. Fungal endosymbiosis is widespread among planthoppers in the infraorder Fulgoromorpha and suborder Auchenorrhyncha. We successfully obtained complete mitogenome of five WBPH fungal endosymbionts, belonging to the Ophiocordycipitaceae family, from next-generation sequencing (NGS) reads obtained from S. furcifera samples. These five mitogenomes range in length from 55,390 bp to 55,406 bp, which is shorter than the mitogenome of the fungal endosymbiont found in Ricania speculum, black planthoppers. Twenty-eight protein-coding genes (PCGs), 12 tRNAs, and 2 rRNAs were found in the mitogenomes. Two single-nucleotide polymorphisms, two insertions, and three deletions were identified among the five mitogenomes, which were fewer in number than those of four species of Ophiocordycipitaceae, Ophiocordyceps sinensis, Hirsutella thompsonii, Hirsutella rhossiliensis, and Tolypocladium inflatum. Noticeably short lengths (up to 18 bp) of simple sequence repeats were identified in the five WBPH fungal endosymbiont mitogenomes. Phylogenetic analysis based on conserved PCGs across 25 Ophiocordycipitaceae mitogenomes revealed that the five mitogenomes were clustered with that of R. speculum, forming an independent clade. In addition to providing the full mitogenome sequences, obtaining complete mitogenomes of WBPH endosymbionts can provide insights into their phylogenetic positions without needing to isolate the mtDNA from the host. This advantage is of value to future studies involving fungal endosymbiont mitogenomes.

Complete Genome Sequence of a Blochmannia Endosymbiont of Colobopsis nipponica

Blochmannia endosymbionts (Gammaproteobacteria) live in bacteriocytes, which are specialized cells found in the genus Camponotus and its neighbor genera. In this announcement, we describe the complete genome sequence of the Blochmannia endosymbiont of Colobopsis nipponica, which originated from a colony collected in the Republic of Korea.

Complete mitochondrial genome of the H3 haplotype Argentine ant Linepithema humile (Mayr, 1868) (Formicidae; Hymenoptera)

The argentine ant, Linepithema humile (Mayr, 1867), is an invasive ant species that has spread across the world. We have determined the mitochondrial genome of L. humile collected in South Korea, which is 15,934 bp containing 10 SNPs and 5 INDELs compared to the previous mitogenome. Most SNPs were found in cox3, followed by cytb. From SNPs our mitogenome was identified as a H3 haplotype, which was previously recorded in Japan and the U.S. while the previous mitogenome was H1 haplotype. Phylogenetic analysis was congruent to previous study within the tribe Leptomyrmecini but not between other tribes of subfamily Dolichoderinae.

Comprehensive Analyses of the Complete Mitochondrial Genome of Figulus binodulus (Coleoptera: Lucanidae)

Figulus binodulus Waterhouse is a small stag beetle distributed in East Asia. We determined the first mitochondrial genome of F. binodulus of which is 16,261-bp long including 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNAs, and a single large noncoding region of 1,717 bp. Gene order of F. binodulus is identical to the ancestral insect mitochondrial gene order as in most other stag beetle species. All of 22 tRNAs could be shaped into typical clover-leaf structure except trnSer1. Comparative analyses of 21 Lucanidae mitochondrial genomes was conducted in aspect of their length and AT-GC ratio. Nucleotide diversities analyses provide that cox1 and cox2 in Lucanidae are less diverse than those of Scarabaeoidea. Fifty simple sequence repeats (SSRs) were identified on F. binodulus mitochondrial genome. Comparative analysis of SSRs among five mitochondrial genomes displayed similar trend along with SSR types. Figulus binodulus was sister to all other available family Lucanidae species in the phylogenetic tree.