Search

Most orthopteran insects are phytophagous and some are important pests in agriculture and forests. Many intestinal microflora of Orthoptera insects have been reported, primarily from Acridoidea and there have been few reports of other taxa. In this study, we collected 15 individuals representing five species (Ruspolia lineosa, Tetrix japonica, Erianthus versicolor, Gryllotalpa orientalis and Teleogryllus emma) belonging to five orthopteran superfamilies (Tettigonioidea, Tetrigoidea, Eumastacoidea, Gryllotalpoidea and Grylloidea) to characterise and compare the gut microbiota with greater taxonomic width by performing sequencing analysis of the 16S rRNA V4 region in gut material. A total of 606,053 high-quality sequences and 3,105 OTUs were acquired from 15 gut samples representing 24 phyla, 48 classes, 69 orders, 133 families and 219 genera. Firmicutes and bacteria were the most abundant phyla, followed by Bacteroidetes, Cyanobacteria, Actinobacteria and Acidobacteria. At the genus level, Serratia, Citrobacter, Wolbachia, Lactobacillus and Parabacteroides were the most predominant genera in R. lineosa, T. japonica, E. versicolor, G. orientalis and T. emma, respectively. Both Principal Coordinates Analysis (PCoA) and heatmap results revealed significant differences in bacterial community composition across species. Additionally, alpha diversity analysis indicated the bacterial richness was significantly different amongst the five species.

Abstract Background Amino acid substitution models play an important role in inferring phylogenies from proteins. Although different amino acid substitution models have been proposed, only a few were estimated from mitochondrial protein sequences for specific taxa such as the mtArt model for Arthropoda. The increasing of mitochondrial genome data from broad Orthoptera taxa provides an opportunity to estimate the Orthoptera-specific mitochondrial amino acid empirical model. Results We sequenced complete mitochondrial genomes of 54 Orthoptera species, and estimated an amino acid substitution model (named mtOrt) by maximum likelihood method based on the 283 complete mitochondrial genomes available currently. The results indicated that there are obvious differences between mtOrt and the existing models, and the new model can better fit the Orthoptera mitochondrial protein datasets. Moreover, topologies of trees constructed using mtOrt and existing models are frequently different. MtOrt does indeed have an impact on likelihood improvement as well as tree topologies. The comparisons between the topologies of trees constructed using mtOrt and existing models show that the new model outperforms the existing models in inferring phylogenies from Orthoptera mitochondrial protein data. Conclusions The new mitochondrial amino acid substitution model of Orthoptera shows obvious differences from the existing models, and outperforms the existing models in inferring phylogenies from Orthoptera mitochondrial protein sequences.

In the present study, we obtained and annotated the complete mitochondrial genome (mitogenome) of Traulia minuta. The length of the whole mitogenome was 15,636 bp and the AT content of the complete mitogenome was 74.5%. All protein-coding genes (PCGs) started with typical ATN codon and ended with complete TAA/TAG codons except Nad5, which ended with incomplete T codon. The phylogenetic tree indicated that T. minuta was clustered together with T. szetschuanensis.

The complete mitochondrial genome (mitogenome) of Euchorthippus unicolor was sequenced for the first time with a length of 15,629 bp. The base nucleotide composition in the mitogenome of E. unicolor was: A(43.3%), T(32.8%), C(13.7%), G(10.2%), and AT(76.1%), respectively. All protein-coding genes start with typical ATN codon except cox1, which initiates with CCG codon instead and ends with either complete TAA/TAG codons or incomplete TA(a) codons. The phylogenetic analysis indicated that Euchorthippus unicolor was clustered with genus Gomphocerus species.

Insects are the most abundant animals on earth, and many are agriculture pests. Currently, we have to resort to chemical pesticides for suppressing pest populations, which lead to environmental pollution, health risk and ecological imbalance. The living environments of most insects are full of various species of pathogens that can enter insects via the mouths, tracheae and wounds. In this review, we summarize on the insect immune responses against pathogens and correspondingly the pathogenic suppression on the host innate immunity. Many individuals with mutations in important immune-related genes are genetically manipulated in laboratories to show low rates of survival even when kept in conventionally reared environment, which indicates that inhibition on the innate immunity could be a potential mode of biological pest control. With the knowledge accumulated on insect immunity, it is time for us to consider developing novel methods for biological pest control by suppressing immune activity. [ABSTRACT FROM AUTHOR]

Background: The grasshopper Shirakiacris shirakii is an important agricultural pest and feeds mainly on gramineous plants, thereby causing economic damage to a wide range of crops. However, genomic information on this species is extremely limited thus far, and transcriptome data relevant to insecticide resistance and pest control are also not available. Methods: The transcriptome of S. shirakii was sequenced using the Illumina HiSeq platform, and we de novo assembled the transcriptome. Results: Its sequencing produced a total of 105,408,878 clean reads, and the de novo assembly revealed 74,657 unigenes with an average length of 680 bp and N50 of 1057 bp. A total of 28,173 unigenes were annotated for the NCBI non-redundant protein sequences (Nr), NCBI non-redundant nucleotide sequences (Nt), a manually-annotated and reviewed protein sequence database (Swiss-Prot), Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. Based on the Nr annotation results, we manually identified 79 unigenes encoding cytochrome P450 monooxygenases (P450s), 36 unigenes encoding carboxylesterases (CarEs) and 36 unigenes encoding glutathione S-transferases (GSTs) in S. shirakii. Core RNAi components relevant to miroRNA, siRNA and piRNA pathways, including Pasha, Loquacious, Argonaute-1, Argonaute-2, Argonaute-3, Zucchini, Aubergine, enhanced RNAi-1 and Piwi, were expressed in S. shirakii. We also identified five unigenes that were homologous to the Sid-1 gene. In addition, the analysis of differential gene expressions revealed that a total of 19,764 unigenes were up-regulated and 4185 unigenes were down-regulated in larvae. In total, we predicted 7504 simple sequence repeats (SSRs) from 74,657 unigenes. Conclusions: The comprehensive de novo transcriptomic data of S. shirakii will offer a series of valuable molecular resources for better studying insecticide resistance, RNAi and molecular marker discovery in the transcriptome. [ABSTRACT FROM AUTHOR]

In this study, the whole mitochondrial genomes (mitogenomes) from four species were sequenced. The complete mitochondrial genomes of Sinopodisma pieli , S. houshana , S. qinlingensis , and S. wulingshanensis are 15,857 bp, 15,818 bp, 15,843 bp, and 15,872 bp in size, respectively. The 13 protein-coding genes (PCGs) begin with typical ATN codons, except for COXI in S. qinlingensis , which begins with ACC. The highest A+T content in all the sequenced orthopteran mitogenomes is 76.8% ( S. qinlingensis ), followed by 76.5% ( S. wulingshanensis ), 76.4% ( S. pieli ) and 76.4% ( S. houshana ) (measured on the major strand). The long polythymine stretches (T-stretch) in the A+T-rich region of the four species are not adjacent to the trnI locus but are inside the stem-loop sequences on the major strand. Moreover, several repeated elements are found in the A+T-rich region of the four species. Phylogenetic analysis based on 53 mitochondrial genomes using Bayesian Inference (BI) and Maximum Likelihood (ML) revealed that Melanoplinae (Podismini) was a monophyletic group; however, the monophyly of Sinopodisma was not supported. These data will provide important information for a better understanding of the phylogenetic relationship of Melanoplinae., (Qiu Zhongying, Chang Huihui, Yuan Hao, Huang Yuan, Lu Huimeng, Li Xia, Gou Xingchun.)