Characterization of the complete mitochondrial genome of Orthaga olivacea Warre (Lepidoptera Pyralidae) and comparison with other Lepidopteran insects

Novel insight into lepidopteran phylogenetics from the mitochondrial genome of the apple fruit moth of the family Argyresthiidae

BACKGROUND

The order Lepidoptera has an abundance of species, including both agriculturally beneficial and detrimental insects. Molecular data has been used to investigate the phylogenetic relationships of major subdivisions in Lepidoptera, which has enhanced our understanding of the evolutionary relationships at the family and superfamily levels. However, the phylogenetic placement of many superfamilies and/or families in this order is still unknown. In this study, we determine the systematic status of the family Argyresthiidae within Lepidoptera and explore its phylogenetic affinities and implications for the evolution of the order. We describe the first mitochondrial (mt) genome from a member of Argyresthiidae, the apple fruit moth Argyresthia conjugella. The insect is an important pest on apples in Fennoscandia, as it switches hosts when the main host fails to produce crops.

RESULTS

The mt genome of A. conjugella contains 16,044 bp and encodes all 37 genes commonly found in insect mt genomes, including 13 protein-coding genes (PCGs), two ribosomal RNAs, 22 transfer RNAs, and a large control region (1101 bp). The nucleotide composition was extremely AT-rich (82%). All detected PCGs (13) began with an ATN codon and terminated with a TAA stop codon, except the start codon in cox1 is ATT. All 22 tRNAs had cloverleaf secondary structures, except trnS1, where one of the dihydrouridine (DHU) arms is missing, reflecting potential differences in gene expression. When compared to the mt genomes of 507 other Lepidoptera representing 18 superfamilies and 42 families, phylogenomic analyses found that A. conjugella had the closest relationship with the Plutellidae family (Yponomeutoidea-super family). We also detected a sister relationship between Yponomeutoidea and the superfamily Tineidae.

CONCLUSIONS

Our results underline the potential importance of mt genomes in comparative genomic analyses of Lepidoptera species and provide valuable evolutionary insight across the tree of Lepidoptera species.

Complete Mitochondrial Genome Characterization of Schrankia costaestrigalis (Insecta: Erebidae: Hypenodinae) and Its Phylogenetic Implication

The pinion-streaked snout Schrankia costaestrigalis is a new potato pest that has recently been recorded in China. In this study, we analyzed the complete mitochondrial genome of S. costaestrigalis. The results revealed the mitogenome (GenBank: OQ181231) to occur as a circular DNA molecule of 16,376 bp with 51.001% AT content, including 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, 2 ribosomal RNA (rRNA) genes, and 1 control region. Notably, the PCGs exhibited typical ATN (Met) start codons, including cox1, which deviated from the usual CGA start codon observed in other lepidopteran mitogenomes, and followed the conventional TAN stop codons. The 22 tRNA genes demonstrated the ability to form a cloverleaf structure, with the exception of trnS1-NCU, which lacked the DHU arm present in other Erebidae mitogenomes. Additionally, conserved motifs like "ATAGA + poly-T (19 bp) stretch" and five microsatellite-like elements (TA) were identified in the AT-rich region. The phylogenetic trees revealed that the Hypenodinae subfamily forms an independent lineage closely related to Erebinae and Catocalinae. The comprehensive mitogenome of S. costaestrigalis will greatly enhance future studies focused on the molecular classification and phylogenetic understanding of the Hypenodinae subfamily within the larger family Erebidae.

Enhanced Resolution of Evolution and Phylogeny of the Moths Inferred from Nineteen Mitochondrial Genomes

The vast majority (approximately 90%) of Lepidoptera species belong to moths whose phylogeny has been widely discussed and highly controversial. For the further understanding of phylogenetic relationships of moths, nineteen nearly complete mitochondrial genomes (mitogenomes) of moths involved in six major lineages were sequenced and characterized. These mitogenomes ranged from 15,177 bp (Cyclidia fractifasciata) to 15,749 bp (Ophthalmitis albosignaria) in length, comprising of the core 37 mitochondrial genes (13 protein-coding genes (PCGs) + 22 tRNAs + two rRNAs) and an incomplete control region. The order and orientation of genes showed the same pattern and the gene order of trnM-trnI-trnQ showed a typical rearrangement of Lepidoptera compared with the ancestral order of trnI-trnQ-trnM. Among these 13 PCGs, ATP8 exhibited the fastest evolutionary rate, and Drepanidae showed the highest average evolutionary rate among six families involved in 66 species. The phylogenetic analyses based on the dataset of 13 PCGs suggested the relationship of (Notodontidae + (Noctuidae + Erebidae)) + (Geometridae + (Sphingidae + Drepanidae)), which suggested a slightly different pattern from previous studies. Most groups were well defined in the subfamily level except Erebidae, which was not fully consistent across bayesian and maximum likelihood methods. Several formerly unassigned tribes of Geometridae were suggested based on mitogenome sequences despite a not very strong support in partial nodes. The study of mitogenomes of these moths can provide fundamental information of mitogenome architecture, and the phylogenetic position of moths, and contributes to further phylogeographical studies and the biological control of pests.

Organization of the mitochondrial genome of Ramulus irregulatiter dentatus (Phasmatidae: Phasmatidae)

Recently, the species of the insect order Phasmatodea, have attracted the interest of more and more enthusiasts. Here, we obtained the complete mitochondrial genome of Ramulus irregulatiter dentatus (R. irregulatiter dentatus), which belongs to the subfamily of Phasmatidae, detected by Illumina next-generation sequencing. The entire mitochondrial genome is 16,060 bp in length and contains a standard set of 13 protein-coding genes, 22 transfer RNA genes (tRNAs), 2 ribosomal RNA genes (rRNAs), and a putative A + T-rich region. The base composition and codon usage were typical of Phasmatodea species. The mitochondrial gene organization (37 genes) was consistent with that of other Phasmatidae. A phylogenetic tree was built from the sequence information of the 13 protein-coding genes by Bayesian analyses. The newly sequenced R. irregulatiter dentatus was most closely related to the family Phasmatidae. The complete mitochondrial genome of R. irregulatiter dentatus also provides valuable molecular information for future studies on Phasmatidae insect taxonomy and a framework to unveil more of their cryptic and unknown diversity, so that it can be used to control forest pests and protect crops.

Comparative mitochondrial genome analysis and phylogenetic relationship among lepidopteran species

Lepidoptera has rich species including many agricultural pests and economical insects around the world. The mitochondrial genomes (mitogenomes) were utilized to explore the phylogenetic relationships between difference taxonomic levels in Lepidoptera. However, the knowledge of mitogenomic characteristics and phylogenetic position about superfamily-level in this order is unresolved. In this study, we integrated 794 mitogenomes consisting of 37 genes and a noncoding control region, which covered 26 lepidopteran superfamilies from newly sequenced and publicly available genomes for comparative genomic and phylogenetic analysis. In primitive taxon, putative start codon of cox1 gene was ATA or ATT instead of CGA, but stop codon of that showed four types, namely TAA, TAG, TA and T. The 7-bp overlap between atp8 and atp6 presented as "ATGATAA". Moreover, the most frequently utilized amino acids were leucine (UUA) in 13 PCGs. Phylogenetic analysis showed that the main backbone relationship in Lepidoptera was (Hepialoidea + (Nepticuloidea + (Adeloidea + (Tischerioidea + (Tineoidea + (Yponomeutoidea + (Gracillarioidea + (Papilionoidea + ((Zygaenoidea + Tortricoidea) + (Gelechioidea + (Pyraloidea + ((Geometroidea + Noctuoidea) + (Lasiocampoidea + Bombycoidea))))))))))))).

The First Mitogenomes of the Subfamily Odontiinae (Lepidoptera, Crambidae) and Phylogenetic Analysis of Pyraloidea

Simple Summary

The Odontiinae is a small group in the Pyraloidea comprised of 388 species in 88 genera, but externally, these moths are diverse, including heterogeneous maculation and a size range from 9 to 50 mm in total wingspan. The monophyly of Pyraloidea and the two families (Pyralidae and Crambidae) is well supported by phylogenetic analyses based on morphology and molecular data of multiple nuclear genes. However, only a few mito-phylogenetic analyses have been conducted and no mitogenome of Odontiinae species has been reported. Three complete mitogenomes of odontiine species were sequenced and analyzed for the first time herein. The results showed that Odontiinae mitogenomes shared similar genomic characters with other Pyraloidea. The phylogenetic analyses based on 13 PCGs of mitogenomes confirmed the monophyly of Odontiinae and its position within Crambidae.

Abstract

The complete mitochondrial genomes of three species of Odontiinae were newly sequenced: Dausara latiterminalis Yoshiyasu, Heortia vitessoides (Moore), and Pseudonoorda nigropunctalis (Hampson). These circular and double-stranded mitogenomes vary from 15,084 bp to 15,237 bp in size, including 13 protein-coding genes (PCGs), two ribosomal RNA genes (rRNAs), and 22 transfer RNA genes (tRNAs) and an A + T-rich region. The nucleotide composition indicated a strong A/T bias. Most PCGs are initiated with an ATN codon and terminated by a codon of TAR. All tRNAs could be folded into the clover-leaf structure with the exception of trnS1 (AGN), in which the dihydrouridine (DHU) arm formed a simple loop, and the motif ‘ATAG’ and ‘ATTTA’ in the A + T-rich region was also founded. The phylogenomic analyses covering Odontiinae + 11 subfamilies of Pyraloidea were conducted. Similar topologies were generated from both Bayesian inference (BI) and maximum likelihood (ML) analyses based on the nucleotide and amino acid sequence data. There was some discrepancy in the sister-group relationship of Odontiinae and Glaphyriinae, and the relationships among the subfamilies in the ‘CAMMSS clade’ of the Crambidae. The results of this study suggest that mitogenomic data are useful for resolving the deep-level relationships of Pyraloidea and the topologies generated from amino acid data might be more realistic and reliable. Moreover, more mitogenomic taxon sampling and larger scale analyses with more genes or a combination of mitogenomic and nuclear genes are needed to reconstruct a comprehensive framework of the pyraloid phylogeny.

The complete mitochondrial genome of Orthaga achatina (Lepidoptera: Pyralidae)

Orthaga achatina Butler is an important pest of camphor trees in Asia. The complete mitochondrial genome of O. achatina was sequenced in this study, which was 15,150 bp in size and comprised of 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, and a control region. Besides, we used a phylogenomic approach to infer evolutionary relationships of O. achatina and 23 Lepidoptera species based on 13 conserved protein sequences of the mitochondrial genome. Our results underline the potential importance of mitochondrial genomes in comparative genomic analyses of Lepidoptera species and provide a robust evolutionary insight across the tree of Lepidoptera insects.

Organization and phylogenetic relationships of the mitochondrial genomes of Speiredonia retorta and other lepidopteran insects

In this study, we analyzed the complete mitochondrial genome (mitogenome) of Speiredonia retorta, which is a pest and a member of the Lepidoptera order. In total, the S. retorta mitogenome was found to contain 15,652 base pairs encoding 13 protein-coding genes (PCGs), 22 tRNAs, 2 rRNAs, as well as an adenine (A) + thymine (T)-rich region. These findings were consistent with the mitogenome composition of other lepidopterans, as we identified all 13 PCGs beginning at ATN codons. We also found that 11 PCGs terminated with canonical stop codons, whereas cox2 and nad4 exhibited incomplete termination codons. By analyzing the mitogenome of S. retorta using Bayesian inference (BI) and maximum likelihood (ML) models, we were able to further confirm that this species is a member of the Erebidae family.