PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Insecta”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 739 records · Page 41Linked to original sources

Assessment of the universality and utility of a set of conserved mitochondrial COI primers in insects.

A set of mitochondrial COI primers has been studied by genomic PCR and many primer combinations shown to work universally well across Insecta. They are able to amplify various amplicons with different variability which enables the selection of a particular amplicon as a suitable DNA marker for a project. The potential usefulness of different amplicons is examined, with analysis on published study cases employing these regions. With respect to their variability, amplicons UEA5/UEA6, UEA7/UEA8 and UEA5/UEA8 could be useful for low- to mid-level phylogenetic analysis, i.e. from species, genus to perhaps family level depending on taxa involved. UEA5/UEA6 will be too conserved for intraspecific studies. Amplicons UEA3/UEA4 and UEA9/UEA10 would be better suited to low-level phylogenetic investigations, such a analysis of relationships among closely related species and population genetic studies. However, these guidelines should not be over-generalized for the reasons given. Amplification conditions of various primer combinations, and general problems in the use of conserved PCR primers are discussed.

Conserved Sequence↗

The regulation of juvenile hormone production in arthropods. Functional and evolutionary perspectives.

Although sesquiterpenoids are probably the ancestral regulators of reproduction and secondarily of metamorphosis in arthropods, our discussion suggests that the neuropeptides that regulate the biosynthesis of these compounds have arisen on several distinct occasions. These peptides probably occurred originally as regulators of other physiological processes and were subsequently co-opted for the regulation of sesquiterpenoid biosynthesis, perhaps first in adult forms and thereafter in larval forms. The evolution of peptides to assume additional physiological functions probably occurred as a result of gene duplication, both at the peptide level and at the receptor level. There are likely to be numerous regulators of sesquiterpenoid biosynthesis in both Insecta and Crustacea, and investigations to date have only begun to reveal the host of peptide families involved in the regulation of juvenile hormone-related biosynthesis across the arthropods.

Amino Acid Sequence↗

The gut of the soil microarthropod Folsomia candida (Collembola) is a frequently changeable but selective habitat and a vector for microorganisms.

Interaction potentials between soil microarthropods and microorganisms were investigated with Folsomia candida (Insecta, Collembola) in microcosm laboratory experiments. Microscopic analysis revealed that the volumes of the simple, rod-shaped guts of adult specimens varied with their feeding activity, from 0.7 to 11.2 nl. A dense layer of bacterial cells, associated with the peritrophic membrane, was detected in the midgut by scanning electron microscopy. Depending on the molting stage, which occurred at intervals of approximately 4 days, numbers of heterotrophic, aerobic gut bacteria changed from 4.9 x 10(2) to 2.3 x 10(6) CFU per specimen. A total of 11 different taxonomic bacterial groups and the filamentous fungus Acremonium charticola were isolated from the guts of five F. candida specimens. The most abundant isolate was related to Erwinia amylovora (96.2% DNA sequence similarity to its 16S rRNA gene). F. candida preferred to feed on Pseudomonas putida and three indigenous gut isolates rather than eight different type culture strains. When luciferase reporter gene-tagged bacterial strains were pulse fed to F. candida, gut isolates were continuously shed for 8 days to several weeks but Escherichia coli HB101 was shed for only 1 day. Ratios of ingested to released bacterial cells demonstrated that populations of nonindigenous gut bacteria like Sinorhizobium meliloti L33 and E. coli HB101 were reduced by more than 4 orders of magnitude but that the population of gut isolate Alcaligenes faecalis HR4 was reduced only 500-fold. This work demonstrates that F. candida represents a frequently changeable but selective habitat for bacteria in terrestrial environments and that microarthropods have to be considered factors that modify soil microbial communities.

Animals↗

Purification and characterization of a high-molecular-weight insecticidal protein complex produced by the entomopathogenic bacterium photorhabdus luminescens

Photorhabdus luminescens is a gram-negative enteric bacterium that is found in association with entomopathogenic nematodes of the family Heterorhabditidae. The nematodes infect a variety of soil-dwelling insects. Upon entering an insect host, the nematode releases P. luminescens cells from its intestinal tract, and the bacteria quickly establish a lethal septicemia. When grown in peptone broth, in the absence of the nematodes, the bacteria produce a protein toxin complex that is lethal when fed to, or injected into the hemolymph of, Manduca sexta larvae and several other insect species. The toxin purified as a protein complex which has an estimated molecular weight of 1,000,000 and contains no protease, phospholipase, or hemolytic activity and only a trace of lipase activity. The purified toxin possesses insecticidal activity whether injected or given orally. Analyses of the denatured complex by sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed it to be composed of several protein subunits ranging in size from 30 to 200 kDa. The complex was further separated by native gel electrophoresis into three components, two of which retained insecticidal activity. The purified native toxin complex was found to be active in nanogram concentrations against insects representing four orders of the class Insecta.

Journal Article↗

Organization of the mitochondrial genomes of whiteflies, aphids, and psyllids (Hemiptera, Sternorrhyncha).

BACKGROUND: With some exceptions, mitochondria within the class Insecta have the same gene content, and generally, a similar gene order allowing the proposal of an ancestral gene order. The principal exceptions are several orders within the Hemipteroid assemblage including the order Thysanoptera, a sister group of the order Hemiptera. Within the Hemiptera, there are available a number of completely sequenced mitochondrial genomes that have a gene order similar to that of the proposed ancestor. None, however, are available from the suborder Sternorryncha that includes whiteflies, psyllids and aphids. RESULTS: We have determined the complete nucleotide sequence of the mitochondrial genomes of six species of whiteflies, one psyllid and one aphid. Two species of whiteflies, one psyllid and one aphid have mitochondrial genomes with a gene order very similar to that of the proposed insect ancestor. The remaining four species of whiteflies had variations in the gene order. In all cases, there was the excision of a DNA fragment encoding for cytochrome oxidase subunit III(COIII)-tRNAgly-NADH dehydrogenase subunit 3(ND3)-tRNAala-tRNAarg-tRNAasn from the ancestral position between genes for ATP synthase subunit 6 and NADH dehydrogenase subunit 5. Based on the position in which all or part of this fragment was inserted, the mitochondria could be subdivided into four different gene arrangement types. PCR amplification spanning from COIII to genes outside the inserted region and sequence determination of the resulting fragments, indicated that different whitefly species could be placed into one of these arrangement types. A phylogenetic analysis of 19 whitefly species based on genes for mitochondrial cytochrome b, NADH dehydrogenase subunit 1, and 16S ribosomal DNA as well as cospeciating endosymbiont 16S and 23S ribosomal DNA indicated a clustering of species that corresponded to the gene arrangement types. CONCLUSIONS: In whiteflies, the region of the mitochondrial genome consisting of genes encoding for COIII-tRNAgly-ND3-tRNAala-tRNAarg-tRNAasn can be transposed from its ancestral position to four different locations on the mitochondrial genome. Related species within clusters established by phylogenetic analysis of host and endosymbiont genes have the same mitochondrial gene arrangement indicating a transposition in the ancestor of these clusters.

Animals↗

The Sinbad retrotransposon from the genome of the human blood fluke, Schistosoma mansoni, and the distribution of related Pao-like elements.

BACKGROUND: Of the major families of long terminal repeat (LTR) retrotransposons, the Pao/BEL family is probably the least well studied. It is becoming apparent that numerous LTR retrotransposons and other mobile genetic elements have colonized the genome of the human blood fluke, Schistosoma mansoni. RESULTS: A proviral form of Sinbad, a new LTR retrotransposon, was identified in the genome of S. mansoni. Phylogenetic analysis indicated that Sinbad belongs to one of five discreet subfamilies of Pao/BEL like elements. BLAST searches of whole genomes and EST databases indicated that members of this clade occurred in species of the Insecta, Nematoda, Echinodermata and Chordata, as well as Platyhelminthes, but were absent from all plants, fungi and lower eukaryotes examined. Among the deuterostomes examined, only aquatic species harbored these types of elements. All four species of nematode examined were positive for Sinbad sequences, although among insect and vertebrate genomes, some were positive and some negative. The full length, consensus Sinbad retrotransposon was 6,287 bp long and was flanked at its 5'- and 3'-ends by identical LTRs of 386 bp. Sinbad displayed a triple Cys-His RNA binding motif characteristic of Gag of Pao/BEL-like elements, followed by the enzymatic domains of protease, reverse transcriptase (RT), RNAseH, and integrase, in that order. A phylogenetic tree of deduced RT sequences from 26 elements revealed that Sinbad was most closely related to an unnamed element from the zebrafish Danio rerio and to Saci-1, also from S. mansoni. It was also closely related to Pao from Bombyx mori and to Ninja of Drosophila simulans. Sinbad was only distantly related to the other schistosome LTR retrotransposons Boudicca, Gulliver, Saci-2, Saci-3, and Fugitive, which are gypsy-like. Southern hybridization and bioinformatics analyses indicated that there were about 50 copies of Sinbad in the S. mansoni genome. The presence of ESTs representing transcripts of Sinbad in numerous developmental stages of S. mansoni along with the identical 5'- and 3'-LTR sequences suggests that Sinbad is an active retrotransposon. CONCLUSION: Sinbad is a Pao/BEL type retrotransposon from the genome of S. mansoni. The Pao/BEL group appears to be comprised of at least five discrete subfamilies, which tend to cluster with host species phylogeny. Pao/BEL type elements appear to have colonized only the genomes of the Animalia. The distribution of these elements in the Ecdysozoa, Deuterostomia, and Lophotrochozoa is discontinuous, suggesting horizontal transmission and/or efficient elimination of Pao-like mobile genetic elements from some genomes.

Amino Acid Motifs↗

The use of Open Reading frame ESTs (ORESTES) for analysis of the honey bee transcriptome.

BACKGROUND: The ongoing efforts to sequence the honey bee genome require additional initiatives to define its transcriptome. Towards this end, we employed the Open Reading frame ESTs (ORESTES) strategy to generate profiles for the life cycle of Apis mellifera workers. RESULTS: Of the 5,021 ORESTES, 35.2% matched with previously deposited Apis ESTs. The analysis of the remaining sequences defined a set of putative orthologs whose majority had their best-match hits with Anopheles and Drosophila genes. CAP3 assembly of the Apis ORESTES with the already existing 15,500 Apis ESTs generated 3,408 contigs. BLASTX comparison of these contigs with protein sets of organisms representing distinct phylogenetic clades revealed a total of 1,629 contigs that Apis mellifera shares with different taxa. Most (41%) represent genes that are in common to all taxa, another 21% are shared between metazoans (Bilateria), and 16% are shared only within the Insecta clade. A set of 23 putative genes presented a best match with human genes, many of which encode factors related to cell signaling/signal transduction. 1,779 contigs (52%) did not match any known sequence. Applying a correction factor deduced from a parallel analysis performed with Drosophila melanogaster ORESTES, we estimate that approximately half of these no-match ESTs contigs (22%) should represent Apis-specific genes. CONCLUSIONS: The versatile and cost-efficient ORESTES approach produced minilibraries for honey bee life cycle stages. Such information on central gene regions contributes to genome annotation and also lends itself to cross-transcriptome comparisons to reveal evolutionary trends in insect genomes.

Animals↗

Crustacean (malacostracan) Hox genes and the evolution of the arthropod trunk.

Representatives of the Insecta and the Malacostraca (higher crustaceans) have highly derived body plans subdivided into several tagma, groups of segments united by a common function and/or morphology. The tagmatization of segments in the trunk, the part of the body between head and telson, in both lineages is thought to have evolved independently from ancestors with a distinct head but a homonomous, undifferentiated trunk. In the branchiopod crustacean, Artemia franciscana, the trunk Hox genes are expressed in broad overlapping domains suggesting a conserved ancestral state (Averof, M. and Akam, M. (1995) Nature 376, 420-423). In comparison, in insects, the Antennapedia-class genes of the homeotic clusters are more regionally deployed into distinct domains where they serve to control the morphology of the different trunk segments. Thus an originally Artemia-like pattern of homeotic gene expression has apparently been modified in the insect lineage associated with and perhaps facilitating the observed pattern of tagmatization. Since insects are the only arthropods with a derived trunk tagmosis tested to date, we examined the expression patterns of the Hox genes Antp, Ubx and abd-A in the malacostracan crustacean Porcellio scaber (Oniscidae, Isopoda). We found that, unlike the pattern seen in Artemia, these genes are expressed in well-defined discrete domains coinciding with tagmatic boundaries which are distinct from those of the insects. Our observations suggest that, during the independent tagmatization in insects and malacostracan crustaceans, the homologous 'trunk' genes evolved to perform different developmental functions. We also propose that, in each lineage, the changes in Hox gene expression pattern may have been important in trunk tagmatization.

Amino Acid Sequence↗

FUNCTION OF THE TENSOR MUSCLE IN THE CICADA TIBICEN LINNEI

The calling song and the disturbance squawk of the cicada Tibicen linnei (Insecta: Homoptera) are described in terms of their physical parameters. The calling song is composed of quiet parts, which are very similar to the disturbance squawk, and loud parts, which are amplitude- and rate-modulated. The role of the tensor muscle acting on the tymbal frame in modulating the sound pulse amplitude was investigated. We demonstrate by tensor nerve recordings, by mechanical mimicking of the tensor muscle action and by electrical stimulation of the tensor nerve, that the contraction of the tensor muscle is responsible for (a) initiating sound production and (b) modulating the sound pulse amplitude. These results allow us to construct a model which suggests that the tensor shifts the tymbal into a mechanical working range that enables sound production and modulation of the sound pulse amplitude.

Journal Article↗

The genome sequence of the common green lacewing, Chrysoperla carnea (Stephens, 1836).

We present a genome assembly from an individual female Chrysoperla carnea (a common green lacewing; Arthropoda; Insecta; Neuroptera; Chrysopidae). The genome sequence is 560 megabases in span. The majority of the assembly (95.70%) is scaffolded into six chromosomal pseudomolecules, with the X sex chromosome assembled. Gene annotation of this assembly by the NCBI Eukaryotic Genome Annotation Pipeline has identified 12,985 protein coding genes.

Chrysoperla carnea↗

The genome sequence of the plain-faced dronefly, Eristalis arbustorum (Linnaeus, 1758).

We present a genome assembly from an individual female Eristalis arbustorum (the plain-faced dronefly; Arthropoda; Insecta; Diptera; Syriphidae). The genome sequence is 451 megabases in span. The majority of the assembly (94.71%) is scaffolded into 6 chromosomal pseudomolecules, with the X sex chromosome assembled. The complete mitochondrial genome was also assembled and is 16.0 kilobases in length.

Diptera↗

The genome sequence of the bronze furrow bee, Seladonia tumulorum (Linnaeus, 1758).

We present the haploid genome assembly of an individual male Seladonia tumulorum (the bronze furrow bee; Arthropoda; Insecta; Hymenoptera; Halictidae). The genome sequence is 479 megabases in span. Most of the assembly (84.28%) is scaffolded into 17 chromosomal pseudomolecules. The mitochondrial genome was also assembled and is 17.3 kilobases in length. Gene annotation of this assembly on Ensembl identified 19,308 protein-coding genes. This assembly was generated as part of the Darwin Tree of Life project, which produces reference genomes for eukaryotic species found in Britain and Ireland.

Hymenoptera↗

The genome sequence of the Adonis blue, Lysandra bellargus (Rottemburg, 1775).

We present a genome assembly from an individual female Lysandra bellargus (the Adonis blue; Arthropoda; Insecta; Lepidoptera; Lycaenidae). The genome sequence is 529 megabases in span. The majority of the assembly (99.93%) is scaffolded into 46 chromosomal pseudomolecules with the W and Z sex chromosomes assembled. The complete mitochondrial genome was also assembled and is 15.6 kilobases in length. Gene annotation of this assembly on Ensembl has identified 13,249 protein coding genes.

Adonis blue↗

The genome sequence of the Red-green Carpet, Chloroclysta siterata (Hufnagel, 1767).

We present a genome assembly from an individual male Chloroclysta siterata (the Red-green Carpet; Arthropoda; Insecta; Lepidoptera; Geometridae). The genome sequence is 437.9 megabases in span. Most of the assembly is scaffolded into 21 chromosomal pseudomolecules including the Z sex chromosome. The mitochondrial genome has also been assembled and is 16.7 kilobases in length. Gene annotation of this assembly on Ensembl identified 11,814 protein coding genes.

Chloroclysta siterata↗

The genome sequence of the Tufted Button, Acleris cristana (Denis & Schiffermüller, 1775).

We present a genome assembly from an individual female Acleris cristana (the Tufted Button; Arthropoda; Insecta; Lepidoptera; Tortricidae). The genome sequence is 562.6 megabases in span. Most of the assembly is scaffolded into 31 chromosomal pseudomolecules, including the W and Z sex chromosomes. The mitochondrial genome has also been assembled and is 16.1 kilobases in length. Gene annotation of this assembly on Ensembl identified 12,598 protein coding genes.

Acleris cristana↗

The genome sequence of the small wasp-sawfly, Tenthredo distinguenda (R. Stein, 1885).

We present a genome assembly from an individual male Tenthredo distinguenda (the small wasp-sawfly; Arthropoda; Insecta; Hymenoptera; Tenthredinidae). The genome sequence is 229.4 megabases in span. Most of the assembly is scaffolded into 9 chromosomal pseudomolecules. The mitochondrial genome has also been assembled and is 31.6 kilobases in length. Gene annotation of this assembly on Ensembl identified 11,332 protein coding genes.

Hymenoptera↗

The genome sequence of the Locust Fly, Stomorhina lunata (Fabricius, 1805).

We present a genome assembly from an individual female Stomorhina lunata (the Locust Fly; Arthropoda; Insecta; Diptera; Rhiniidae). The genome sequence is 728.1 megabases in span. Most of the assembly is scaffolded into 6 chromosomal pseudomolecules, including the X sex chromosome. The mitochondrial genome has also been assembled and is 16.49 kilobases in length. Gene annotation of this assembly on Ensembl identified 18,358 protein coding genes.

Diptera↗

The genome sequence of the Coxcomb Prominent, Ptilodon capucinus (Linnaeus, 1758).

We present a genome assembly from an individual male Ptilodon capucinus (the Coxcomb Prominent; Arthropoda; Insecta; Lepidoptera; Notodontidae). The genome sequence is 348.7 megabases in span. The assembly is scaffolded into 31 chromosomal pseudomolecules, including the Z sex chromosome. The mitochondrial genome has also been assembled and is 15.38 kilobases in length. Gene annotation of this assembly on Ensembl identified 16,968 protein coding genes.

Coxcomb Prominent↗