RESUMO
Acanthaspis cincticrus (Stål) is an assassin bug with a specialized camouflaging behavior to ambush ants in the nymphal stages. In this study, we comprehensively sequenced all the life stages of A. cincticrus, including the eggs, five nymph instars, female and male adults using Illumina HiSeq technology. We obtained 176 million clean sequence reads. The assembled 84,055 unigenes were annotated and classified functionally based on protein databases. Among the unigenes, 29.03% were annotated by one or more databases, suggesting their well-conserved functions. Comparison of the gene expression profiles in the egg, nymph and adult stages revealed certain bias. Functional enrichment analysis of significantly differentially expressed genes (SDEGs) showed positive correlation with specific physiological processes within each stage, including venom, aggression, olfactory recognition as well as growth and development. Relative expression of ten SDEGs involved in predation process was validated using quantitative real-time PCR (qRT-PCR).
Assuntos
Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Ninfa/crescimento & desenvolvimento , Ninfa/genética , Comportamento Predatório , Reduviidae/crescimento & desenvolvimento , Reduviidae/genética , Animais , Regulação para Baixo/genética , Genes de Insetos , Anotação de Sequência Molecular , Reprodutibilidade dos Testes , Fatores de Tempo , Transcriptoma/genética , Regulação para Cima/genéticaRESUMO
The plant bug, Nesidiocoris tenuis (Hemiptera: Miridae), is one of the most thermophilous dicyphines in agroecosystems and is widely distributed in China. Little is known regarding the genetic structure of N. tenuis and the effect of historical climatic fluctuations on N. tenuis populations. We analyzed partial sequences of three mitochondrial protein-coding genes (COI, ND2 and CytB) and nuclear genes (5.8S, ITS2 and 28S) for 516 specimens collected from 37 localities across China. Analyses of the combined mitochondrial dataset indicated that the Southwestern China group (SWC) was significantly differentiated from the remaining populations, other Chinese group (OC). Asymmetric migration and high level of gene flow across a long distance within the OC group was detected. The long-distance dispersal of N. tenuis might be affected by air currents and human interference. Both the neutrality tests and mismatch distributions revealed the occurrence of historical population expansion. Bayesian skyline plot analyses with two different substitution rates indicated that N. tenuis might follow the post-LGM (the Last Glacial Maximum) expansion pattern for temperate species. Pleistocene climatic fluctuation, complicated topography and anthropogenic factors, along with other ecological factors (e.g. temperature and air current) might have accounted for the current population structure of N. tenuis.
Assuntos
DNA Mitocondrial , Genética Populacional , Heterópteros/genética , Animais , China , Clima , Haplótipos , Mitocôndrias/genética , Filogeografia , Dinâmica PopulacionalRESUMO
The mitochondrial genome of Adelphocoris fasciaticollis Reuter, an important pest plant bug, is a typical circular DNA molecule of 15,434 bp with 37 genes and 77.4% A + T content. Twenty-three genes are located on the J-strand, the remaining being oriented on the N-strand. Gene order is identical to that of the typical arrangement of insects and other plant bugs. This genome is highly economized with 54 overlapped nucleotides between neighboring genes in 12 locations. All protein-coding genes initiate with ATN codons. All of the 22 tRNAs, ranging from 62 to 71 bp, have the clover-leaf structure. Two tRNAs, trnK and trnS1, use the non-standard anticodons TTT and TCT. The sizes of the large and small ribosomal RNA genes are 1229 and 793 bp, respectively. The control region is 922 bp in length with 78.2% A + T content and includes two 30-bp repeat units and two 35-bp repeat units.
Assuntos
Genoma de Inseto , Genoma Mitocondrial , Heterópteros/genética , Animais , Composição de Bases/genética , Pareamento de Bases/genética , Sequência de Bases , DNA Mitocondrial/genética , Fases de Leitura Aberta/genética , Plantas/parasitologia , RNA de Transferência/genéticaRESUMO
Phylogeographic patterns of some extant plant and vertebrate species have been well studied; however, they are poorly understood in the majority of insects. The study documents analysis of mitochondrial (COI, CYTB and ND5) and nuclear (5.8S rDNA, ITS2 and 28S rDNA) data from 419 individuals of Adelphocoris suturalis, which is one of the main cotton pests found in the 31 locations in China and Japan involved in the study. Results show that the species is highly differentiated between populations from central China and peripheral China regions. Analysis of molecular variance showed a high level of geographical differentiation at different hierarchical levels. Isolation-by-distance test showed no significant correlation between genetic distance and geographical distance among A. suturalis populations, which suggested gene flow is not restricted by distance. In seven peripheral populations, the high levels of genetic differentiation and the small Nem values implied that geographic barriers were more likely restrict gene flow. Neutrality tests and the Bayesian skyline plot suggested population expansion likely happened during the cooling transition between Last Interglacial and Last Glacial Maximum. All lines of evidence suggest that physical barriers, Pleistocene climatic oscillations and geographical heterogeneity have affected the population structure and distribution of this insect in China.
Assuntos
DNA Mitocondrial/genética , DNA Espaçador Ribossômico/genética , Evolução Molecular , Heterópteros/genética , Mitocôndrias/genética , Animais , Sequência de Bases , China , Complexo I de Transporte de Elétrons/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Variação Genética/genética , Gossypium , Heterópteros/fisiologia , Japão , Filogeografia , RNA Ribossômico 28S/genética , RNA Ribossômico 5,8S/genética , Análise de Sequência de DNARESUMO
The 16,299 bp long mitochondrial genome (mitogenome) of a tessaratomid bug, Eusthenes cupreus (Westwood), is reported and analyzed. The mitogenome represents the first sequenced complete mitogenome of the heteropteran family Tessaratomidae. The mitogenome of E. cuopreus is a typical circular DNA molecule with a total AT content of 74.1%, and contains 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, two ribosomal RNA (rRNA) genes, and a control region. The gene arrangement is identical with the most common type in insects. Most PCGs start with the typical ATN codon, except that the initiation codon for COI is TTG. All tRNAs possess the typical clover-leaf structure, except tRNASer(AGN), in which the dihydrouridine (DHU) arm forms a simple loop. Six domains with 45 helices and three domains with 27 helices are predicted in the secondary structures of rrnL and rrnS, respectively. The control region is located between rrnS and tRNA(Ile), including some short microsatellite repeat sequences. In addition, three different repetitive sequences are found in the control region and the tRNA(Ile)-tRNA(Gln)-tRNA(Met)-ND2 gene cluster. One of the unusual features of this mitogenome is the presence of one tRNA(Gln)-like sequence in the control region. This extra tRNA(Gln)-like sequence is 73 bp long, and the anticodon arm is identical to that of the regular tRNA(Gln).
