Search results for "lepidoptera"
showing 10 items of 191 documents
Insights into the Structure of the Vip3Aa Insecticidal Protein by Protease Digestion Analysis
2017
Vip3 proteins are secretable proteins from Bacillus thuringiensis whose mode of action is still poorly understood. In this study, the activation process for Vip3 proteins was closely examined in order to better understand the Vip3Aa protein stability and to shed light on its structure. The Vip3Aa protoxin (of 89 kDa) was treated with trypsin at concentrations from 1:100 to 120:100 (trypsin:Vip3A, w:w). If the action of trypsin was not properly neutralized, the results of SDS-PAGE analysis (as well as those with Agrotis ipsilon midgut juice) equivocally indicated that the protoxin could be completely processed. However, when the proteolytic reaction was efficiently stopped, it was revealed t…
Ephestia kuehniella tolerance to Bacillus thuringiensis Cry1Aa is associated with reduced oligomer formation
2016
The basis of the different susceptibility of Ephestia kuehniella to the Cry1Aa and Cry1Ac δ-endotoxins from Bacillus thuringiensis kurstaki BNS3 was studied. Both toxins bound specifically to the BBMV of E. kuehniella. The result of the ligand blot showed that Cry1Ac bound to three putative receptors of about 100, 65 and 80 kDa and Cry1Aa interacted only with a 100 kDa protein. Pronase digestion of the BBMV-bound toxins was used to analyze the toxin insertion. Both toxins inserted into the BBMV as monomers however, a 14 kDa peptide of α4-α5 which correspond to the oligomeric form of this peptide was detected in case of Cry1Ac only. Analysis of the in vitro oligomerisation of these toxins in…
High Bacterial Agglutination Activity in a Single-CRD C-Type Lectin from Spodoptera exigua (Lepidoptera: Noctuidae)
2017
Lectins are carbohydrate-interacting proteins that play a pivotal role in multiple physiological and developmental aspects of all organisms. They can specifically interact with different bacterial and viral pathogens through carbohydrate-recognition domains (CRD). In addition, lectins are also of biotechnological interest because of their potential use as biosensors for capturing and identifying bacterial species. In this work, three C-type lectins from the Lepidoptera Spodoptera exigua were produced as recombinant proteins and their bacterial agglutination properties were characterized. The lowest protein concentration producing bacterial agglutination against a panel of different Gram+ an…
Food quality affects the expression of antimicrobial peptide genes upon simulated parasite attack in the larvae of greater wax moth
2017
Predator‐prey interactions are an important evolutionary force affecting the immunity of the prey. Parasitoids and mites pierce the cuticle of their prey, which respond by activating their immune system against predatory attacks. Immunity is a costly function for the organism, as it often competes with other life‐history traits for limited nutrients. We tested whether the expression of antimicrobial peptides (AMP) of the larvae of the greater wax moth Galleria mellonella (L.) (Lepidoptera: Pyralidae) changes as a consequence of insertion of a nylon monofilament, which acts like a synthetic parasite. The treatment was done for larvae grown on a high‐quality vs. a low‐quality diet. The expres…
The usefulness of a mathematical model of exposure for environmental risk assessment
2011
We respond to the Comment of Lang et al . [[1][1]] regarding our mathematical model [[2][2]] of exposure of non-target Lepidoptera to Bt -maize pollen expressing Cry1Ab within Europe. Lang et al . remark on the degree to which the model was subject to uncertainty. Perry et al . [[2][2]] did indeed
A mathematical model of exposure of nontarget Lepidoptera to Bt-maize pollen expressing Cry1Ab within Europe
2010
Genetically modified (GM) maize MON810 expresses a Cry1Ab insecticidal protein, derived from Bacillus thuringiensis ( Bt ), toxic to lepidopteran target pests such as Ostrinia nubilalis . An environmental risk to non-target Lepidoptera from this GM crop is exposure to harmful amounts of Bt -containing pollen deposited on host plants in or near MON810 fields. An 11-parameter mathematical model analysed exposure of larvae of three non-target species: the butterflies Inachis io (L.), Vanessa atalanta (L.) and moth Plutella xylostella (L.), in 11 representative maize cultivation regions in four European countries. A mortality–dose relationship was integrated with a dose–distance relationship t…
Host’s genetic background determines the outcome of reciprocal faecal transplantation on life-history traits and microbiome composition
2022
Abstract Background Microbes play a role in their host's fundamental ecological, chemical, and physiological processes. Host life-history traits from defence to growth are therefore determined not only by the abiotic environment and genotype but also by microbiota composition. However, the relative importance and interactive effects of these factors may vary between organisms. Such connections remain particularly elusive in Lepidoptera, which have been argued to lack a permanent microbiome and have microbiota primarily determined by their diet and environment. We tested the microbiome specificity and its influence on life-history traits of two colour genotypes of the wood tiger moth (Arctia…
Evaluating Resistance to Bt Toxin Cry1Ab by F<SUB>2</SUB> Screen in European Populations of Ostrinia nubilalis (Lepidoptera: Crambidae)
2010
ABSTRACT The large-scale cultivation of transgenic crops producing Bacillus thuringiensis (Bt) toxins have already lead to the evolution of Bt resistance in some pest populations targeted by these crops. We used the F2 screening method for further estimating the frequency of resistance alleles of the European corn borer, Ostrinia nubilalis (Hubner) (Lepidoptera: Crambidae), to Bt maize, Zea mays L., producing the CrylAb toxin. In France, Germany, and Italy, 784, 455, and 80 lines of European corn borer were screened for resistance to Mon810 maize, respectively. In Slovakia, 26 lines were screened for resistance to the CrylAb toxin. The cost of F2 screen performed in the four countries varie…
Atypical functioning of female genitalia explains monandry in a butterfly
2021
Monandrous species are rare in nature, especially in animals where males transfer nutrients to females in the ejaculate. The proximate mechanisms responsible for monandry are poorly studied. In butterflies and moths, the male transfers a nutritious spermatophore into the corpus bursae (CB) of the female. The CB is a multifunctional organ that digests the spermatophore and has partial control of the post-mating sexual receptivity of the female. The spermatophore distends the CB and the post-mating sexual receptivity of the female is inversely proportional to the degree of distension. The CB of many butterfly species has a muscular sheath whose contractions mechanically contribute to digest t…
The influence of smoke volatiles on sexual maturation and juvenile hormone biosynthesis in the black army cutworm, Actebia fennica (Lepidoptera: Noct…
2000
0965-1748 (Print) Journal Article Research Support, Non-U.S. Gov't; Outbreaks of the black army cutworm, Actebia fennica, are associated with recently burned sites, where larvae feed on early successional plants. In the present paper we show that smoke volatiles stimulate juvenile hormone biosynthesis in virgin females, resulting in a more rapid rate of oocyte maturation and a significant advance in the age of first calling (the release of the sex pheromone) compared to control females. The ecological implications of this physiological effect are discussed.