366 research outputs found
On the genus Epidiplosis Felt (Diptera: Cecidomyiidae) in East Asia, with descriptions of four new species
Eight species of the genus Epidiplosis Felt are reported, seven from China and one from Russian Far East. Two species from China, E. indica Grover & Chandra and E. reflexa Mamaev, and one from the Russian Far East, E. filifera (Nijveldt), are newly recorded. Four species are described as new to science: E. bicornuta sp. nov., E. campanulata sp. nov., E. lari sp. nov. and E. tuberoforcipata sp. nov. The genus is redescribed. A key to the species is given and all the species are illustrated
A new species of gall midge (Diptera: Cecidomyiidae) attacking hazels, Corylus spp. in China
Hazels, Corylus spp. (Betulaceae) are planted extensively in North and Southwest China as nut-bearing trees. Dasineura heterophylla Jiao & Bu, sp. n., a new species of gall midge that induces galls on leaves, leaf buds and bracts of young fruits of hazels in North China, is described and illustrated based on materials from Tieling, Liaoning, China. This new gall midge is univoltine and pupates in the topsoil. Larvae reduce nut production of hazels, especially in Corylus heterophylla
Comparative and phylogenomic studies on the mitochondrial genomes of Pentatomomorpha (Insecta: Hemiptera: Heteroptera)
<p>Abstract</p> <p>Background</p> <p>Nucleotide sequences and the gene arrangements of mitochondrial genomes are effective tools for resolving phylogenetic problems. Hemipteroid insects are known to possess highly reorganized mitochondrial genomes, but in the suborder Heteroptera (Insecta: Hemiptera), there was only one complete mitochondrial genome sequenced without gene rearrangement and the phylogeny of infraorder Pentatomomorpha in Heteroptera was still uncertain.</p> <p>Results</p> <p>Fifteen mitochondrial genomes of the suborder Heteroptera were sequenced. Gene rearrangements were found as follows: 1) <it>tRNA-I </it>and <it>tRNA-Q </it>switched positions in Aradidae, 2) <it>tRNA-T </it>and <it>tRNA-P </it>switched positions in Largidae and Pyrrhocoridae. Two recombination events were found in Alydidae and Malcidae. The other mt-genomes were organized in the same way as observed in <it>Drosophila yakuba</it>. The phylogenetic analyses of infraorder Pentatomomorpha based on the nucleotide sequence raised the hypothesis of (Aradoidea + (Pentatomoidea + (Pyrrhocoroidea + (Lygaeoidea + Coreoidea)))). The rearrangement of <it>tRNA-T </it>and <it>tRNA-P </it>also linked Largidae and Pyrrhocoridae together. Furthermore, the conserved sequence block in the unusual intergenic spacers between <it>tRNA-H </it>and <it>ND4 </it>favored the monophyly of Lygaeoidea. Tetranucleotide ATCA was inferred to be the initiation codon of <it>ND2 </it>in Cydnidae. No correlation was found between the rates of nucleotide substitution and gene rearrangement. CG content was significantly correlated with the nucleotide substitution rate of each gene. For ND1, there was a positive correlation (<it>P </it>< 0.01) between amino acids variations and hydrophobicity, but a negative correlation (<it>P </it>< 0.01) for ND6. No conserved sequence was found among the control regions and these regions were not always the most AT-rich region of the mt-genome.</p> <p>Conclusion</p> <p>Heteropteran insects are extremely complex groups worthy of further study because of the unusual tetranucleotide initiation codon and their great mt-genomic diversity, including gene rearrangements and recombinations. The mt-genome is a powerful molecular marker for resolving phylogeny at the level of the superfamily and family. Gene rearrangements were not correlated with nucleotide substitution rates. CG content variation caused the different evolutionary patterns among genes. For ND1, in many polar or nonpolar regions the specific identity of the amino acid residues might be more important than maintaining the polarity of these regions, while the opposite is true for ND6. Most sequences of the control regions did not appear to be important for regulatory functions. Finally, we suggest that the term "AT-rich regions" should not be used.</p
Phylogenetic analysis of the true water bugs (Insecta: Hemiptera: Heteroptera: Nepomorpha): evidence from mitochondrial genomes
<p>Abstract</p> <p>Background</p> <p>The true water bugs are grouped in infraorder Nepomorpha (Insecta: Hemiptera: Heteroptera) and are of great economic importance. The phylogenetic relationships within Nepomorpha and the taxonomic hierarchies of Pleoidea and Aphelocheiroidea are uncertain. Most of the previous studies were based on morphological characters without algorithmic assessment. In the latest study, the molecular markers employed in phylogenetic analyses were partial sequences of 16S rDNA and 18S rDNA with a total length about 1 kb. Up to now, no mitochondrial genome of the true water bugs has been sequenced, which is one of the largest data sets that could be compared across animal taxa. In this study we analyzed the unresolved problems in Nepomorpha using evidence from mitochondrial genomes.</p> <p>Results</p> <p>Nine mitochondrial genomes of Nepomorpha and five of other hemipterans were sequenced. These mitochondrial genomes contain the commonly found 37 genes without gene rearrangements. Based on the nucleotide sequences of mt-genomes, Pleoidea is not a member of the Nepomorpha and Aphelocheiroidea should be grouped back into Naucoroidea. Phylogenetic relationships among the superfamilies of Nepomorpha were resolved robustly.</p> <p>Conclusion</p> <p>The mt-genome is an effective data source for resolving intraordinal phylogenetic problems at the superfamily level within Heteroptera. The mitochondrial genomes of the true water bugs are typical insect mt-genomes. Based on the nucleotide sequences of the mt-genomes, we propose the Pleoidea to be a separate heteropteran infraorder. The infraorder Nepomorpha consists of five superfamilies with the relationships (Corixoidea + ((Naucoroidea + Notonectoidea) + (Ochteroidea + Nepoidea))).</p
ATTITUDE CONTROL OF AIR SPRING MOUNTING SYSTEM BASED ON FUZZY CONTROL
ABSTRACT Air spring is a kind of mount with excellent vibration isolation effect and it uses air as its elastic component. But its height is subject to constant change due to air leak or environment temperature and this restricts its engineering application. So some studies on attitude control are carried out, focusing on statically indeterminate and multivariable coupling air spring mounting systems in this paper. The Statically indeterminate problem is transformed through adding the constraint of loading evenness among air springs. After analyzing the model of this controlled object, a new control strategy based on coupling characteristic recognition is presented and combined with fuzzy logic control to realize attitude control of the multivariable coupling system. Finally, a test is conducted to show that the control strategy is feasible and the control system has good static and dynamic properties
Čimbenik prirodne obnove vrste Platycladus orientalis (L.) Franco u Guilinu, Kina
Cypress (Platycladus orientalis (L.) Franco) is one of the important evergreen trees for afforestation in barren mountains, soil consolidation, and water conservation, but natural regeneration of cypress is complex and slow. An understanding of the influence mechanism of the natural regeneration of cypresses is essential for elevating survival and regeneration. This study aimed to clarify the relationship between stand factors, environmental factors, and regeneration of cypress plantations. A total of 42 cypress sample plots in Guilin, China, were selected to evaluate the impact of various stand factors and environmental factors on the regeneration of cypresses using survey statistics and Pearson and Spearmanrank correlation analysis. In this study, cypress has the highest frequency and density of regeneration among all the seedlings in the 18 surveyed forests, but the height structure of cypress seedlings distributes in uneven mode and mainly Grade I (height < 30 cm) seedlings. Low-density herbs and high-density moss mulching had a directly positive effect on the number of cypress regeneration seedlings. Larger soil stone content and gap area can promote cypress regeneration, which is appropriate for cypresses in the seedling stage. In conclusion, timely weeding, proper soil loosening, and improving light transmittance contribute to promoting the regeneration of cypresses.Obična azijska tuja (Platycladus orientalis (L.) Franco) je jedno od važnih zimzelenih stabala za pošumljavanje u neplodnim planinama, za konsolidaciju tla i očuvanje vode, ali prirodna regeneracija obične azijske tuje je složena i spora. Razumijevanje mehanizma utjecaja na prirodnu regeneraciju obične azijske tuje bitno je za poticanje preživljavanja i regeneraciju. Cilj ovog istraživanja je objasniti odnos između šumskih sastojina, okolišnih čimbenika i regeneracije nasada obične azijske tuje. Ukupno 42 uzorka čempresa u Guilinu, Kina, odabrane su za procjenu utjecaja različitih čimbenika sastojine i okolišnih čimbenika na regeneraciju čempresa korištenjem statistike ankete i korelacijske analize Pearson i Spearmanrank. U ovoj studiji, obična azijska tuja ima najveću učestalost i gustoću regeneracije među svim sadnicama ( 18 ) u istraživanoj šumi, ali je visinska struktura sadnica obične azijske tuje raspoređena neravnomjerno, a radi se uglavnom o sadnicama I klase (visina < 30 cm). Bilje niske gustoće i malčiranje mahovine velike gustoće, imali su izravan pozitivan učinak na broj sadnica za regeneraciju obične azijske tuje. Veći sadržaj kamena u tlu i opustošenih površina mogu potaknuti regeneraciju obične azijske tuje, ali je to prikladnije za obične azijske tuje u fazi sadnice. Zaključno, pravodobno plijevljenje korova, pravilno rahljenje tla i poboljšanje propusnosti svjetla mogli bi potaknuti regeneraciju obične azijske tuje
The lncRNA-mediated ceRNA network of Altica viridicyanea is involved in the regulation of the Toll/Imd signaling pathway under antibiotic treatment
Long noncoding RNAs (lncRNAs) play significant roles in the regulation of mRNA expression or in shaping the competing endogenous RNA (ceRNA) network by targeting miRNA. The insect gut is one of the most important tissues due to direct contact with external pathogens and functions in the immune defense against pathogen infection through the innate immune system and symbionts, but there are limited observations on the role of the lncRNA-involved ceRNA network of the Toll/Imd pathway and correlation analysis between this network and bacterial microbiota in the Altica viridicyanea gut. In this research, we constructed and sequenced six RNA sequencing libraries using normal and antibiotic-reared samples, generating a total of 17,193 lncRNAs and 26,361 mRNAs from massive clean data by quality control and bioinformatic analysis. Furthermore, a set of 8,539 differentially expressed lncRNAs (DELs) and 13,263 differentially expressed mRNAs (DEMs), of which related to various immune signaling pathways, such as the Toll/Imd, JAK/STAT, NF-κB, and PI3K-Akt signaling pathways, were obtained between the two experimental groups in A. viridicyanea. In addition, numerous GO and KEGG enrichment analyses were used to annotate the DELs and their target genes. Moreover, six Toll family members and nineteen signal genes from the Toll/Imd signaling pathway were identified and characterized using online tools, and phylogenetic analyses of the above genes proved their classification. Next, a lncRNA-miRNA-mRNA network of the Toll/Imd pathway was built, and it contained different numbers of DEMs in this pathway and related DELs based on prediction and annotation. In addition, qRT-PCR validation and sequencing data were conducted to show the expression patterns of the above DELs and DEMs related to the Toll/Imd signaling pathway. Finally, the correlated investigations between DELs or DEMs of the Toll/Imd signaling pathway and most changes in the gut bacterial microbiota revealed significantly positive or negative relationships between them. The present findings provide essential evidence for innate immune ceRNAs in the beetle gut and uncover new potential relationships between innate immune pathways and the gut bacterial microbiota in insects
Full-Length Genome of an Ogataea polymorpha Strain CBS4732 ura3Δ Reveals Large Duplicated Segments in Subtelomeric Regions
BACKGROUND: Currently, methylotrophic yeasts (e.g., Pichia pastoris, Ogataea polymorpha, and Candida boindii) are subjects of intense genomics studies in basic research and industrial applications. In the genus Ogataea, most research is focused on three basic O. polymorpha strains-CBS4732, NCYC495, and DL-1. However, the relationship between CBS4732, NCYC495, and DL-1 remains unclear, as the genomic differences between them have not be exactly determined without their high-quality complete genomes. As a nutritionally deficient mutant derived from CBS4732, the O. polymorpha strain CBS4732 ura3Δ (named HU-11) is being used for high-yield production of several important proteins or peptides. HU-11 has the same reference genome as CBS4732 (noted as HU-11/CBS4732), because the only genomic difference between them is a 5-bp insertion. RESULTS: In the present study, we have assembled the full-length genome of O. polymorpha HU-11/CBS4732 using high-depth PacBio and Illumina data. Long terminal repeat retrotransposons (LTR-rts), rDNA, 5′ and 3′ telomeric, subtelomeric, low complexity and other repeat regions were exactly determined to improve the genome quality. In brief, the main findings include complete rDNAs, complete LTR-rts, three large duplicated segments in subtelomeric regions and three structural variations between the HU-11/CBS4732 and NCYC495 genomes. These findings are very important for the assembly of full-length genomes of yeast and the correction of assembly errors in the published genomes of Ogataea spp. HU-11/CBS4732 is so phylogenetically close to NCYC495 that the syntenic regions cover nearly 100% of their genomes. Moreover, HU-11/CBS4732 and NCYC495 share a nucleotide identity of 99.5% through their whole genomes. CBS4732 and NCYC495 can be regarded as the same strain in basic research and industrial applications. CONCLUSION: The present study preliminarily revealed the relationship between CBS4732, NCYC495, and DL-1. Our findings provide new opportunities for in-depth understanding of genome evolution in methylotrophic yeasts and lay the foundations for the industrial applications of O. polymorpha CBS4732, NCYC495, DL-1, and their derivative strains. The full-length genome of O. polymorpha HU-11/CBS4732 should be included into the NCBI RefSeq database for future studies of Ogataea spp
The ncRNA-mediated regulatory networks of defensins and lysozymes in Riptortus pedestris: involvement in response to gut bacterial disturbances
Insects depend on humoral immunity against intruders through the secretion of antimicrobial peptides (AMPs) and immune effectors via NF-κB transcription factors, and their fitness is improved by gut bacterial microbiota. Although there are growing numbers of reports on noncoding RNAs (ncRNAs) involving in immune responses against pathogens, comprehensive studies of ncRNA-AMP regulatory networks in Riptortus pedestris, which is one of the widely distributed pests in East Asia, are still not well understood under feeding environmental changes. The objective of this study employed the whole-transcriptome sequencing (WTS) to systematically identify the lncRNAs (long noncoding RNA) and circRNAs (circular RNA) and to obtain their differential expression from the R. pedestris gut under different feeding conditions. Functional annotation indicated that they were mainly enriched in various biological processes with the GO and KEGG databases, especially in immune signaling pathways. Five defensin (four novel members) and eleven lysozyme (nine novel members) family genes were identified and characterized from WTS data, and meanwhile, phylogenetic analysis confirmed their classification. Subsequently, the miRNA–mRNA interaction network of above two AMPs and lncRNA-involved ceRNA (competing endogenous RNA) regulatory network of one lysozyme were predicted and built based on bioinformatic prediction and calculation, and the expression patterns of differentially expressed (DE) defensins, and DE lysozymes and related DE ncRNAs were estimated and selected among all the comparison groups. Finally, to integrate the analyses of WTS and previous 16S rRNA amplicon sequencing, we conducted the Pearson correlation analysis to reveal the significantly positive or negative correlation between above DE AMPs and ncRNAs, as well as most changes in the gut bacterial microbiota at the genus level of R. pedestris. Taken together, the present observations provide great insights into the ncRNA regulatory networks of AMPs in response to rearing environmental changes in insects and uncover new potential strategies for pest control in the future
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