49 research outputs found

    DD04107-Derived neuronal exocytosis inhibitor peptides: Evidences for synaptotagmin-1 as a putative target

    Get PDF
    The analgesic peptide DD04107 (Pal-EEMQRR-NH2) and its acetylated analogue inhibit a-calcitonin gene-related peptide (a-CGRP) exocytotic release from primary sensory neurons. Examining the crystal structure of the SNARE-Synaptotagmin-1(Syt1) complex, we hypothesized that these peptides could inhibit neuronal exocytosis by binding to Syt1, hampering at least partially its interaction with the SNARE complex. To address this hypothesis, we first interrogate the role of individual side-chains on the inhibition of a-CGRP release, finding that E1, M3, Q4 and R6 residues were crucial for activity. CD and NMR conformational analysis showed that linear peptides have tendency to adopt a-helical conformations, but the results with cyclic analogues indicated that this secondary structure is not needed for activity. Isothermal titration calorimetry (ITC) measurements demonstrate a direct interaction of some of these peptides with Syt1-C2B domain, but not with Syt7-C2B region, indicating selectivity. As expected for a compound able to inhibit a-CGRP release, cyclic peptide derivative Pal-E-cyclo[EMQK]R-NH2 showed potent in vivo analgesic activity, in a model of inflammatory pain. Molecular dynamics simulations provided a model consistent with KD values for the interaction of peptides with Syt1-C2B domain, and with their biological activity. Altogether, these results identify Syt1 as a potential new analgesic target. © 202

    Effect of alloy treatment and coiling temperature on microstructure and bending performance of ultra-high strength strip steel

    Get PDF
    Two different high strength B-containing microalloyed steel strips produced in industrial processing conditions, one treated with Ti and the other treated with Al, processed by controlled rolling, accelerated cooling and coiling in two different temperatures ranges [723 K to 733 K (450 °C to 460 °C)] and [633 K to 653 K (360 °C to 380 °C)] were subjected to bend testing. The Ti treated steel coiled at the higher temperature 733 K (460 °C) showed the best bending performance. The relatively softer (tensile strength of and even {112} in the sub-surface region as well as uniformity of through thickness texture of the rolled sheet improve the bendability. In the presence of crack initiators, like coarse and brittle TiN particles found in the Ti treated steel, a harder microstructure and the presence of Cube and Goss texture in the sub-surface layer, seen for the lower coiling temperature can cause local transgranular cleavage cracking. Finally the post-uniform elongation obtained from tensile testing and bendability follow a good correlation

    Recent trends in management strategies for two major maize borers: Ostrinia nubilalis and Sesamia nonagrioides

    Get PDF
    23 p.-2 tab.Stem borers (Lepidoptera) are common cereal pests. In many parts of the world, the species Ostrinia nubilalis and Sesamia nonagrioides stand out as important insect pests of economically important crops such as maize. Their management relied mainly on transgenic host plant resistance over the last 25 years. Technologies based on the insecticidal properties of Bacillus thuringiensis-derived proteins allowed widespread pest population suppression, especially for O. nubilalis. However, the recent discovery of Bt resistance, which has revitalized interest in both pests’ biology and management, may jeopardize the effectiveness of such transgenic technologies. Historical information on O. nubilalis bionomy may need to be reassessed in light of changing climate conditions and changing agricultural practices, as well as increased production of alternate host crops across its distribution range. The current paper examines the bioecology and historical research that has been conducted to manage these two important maize-boring pests.N

    The Present and Future Role of Insect-Resistant Genetically Modified Maize in IPM

    Get PDF
    Commercial, genetically-modified (GM) maize was first planted in the United States (USA, 1996) and Canada (1997) but now is grown in 13 countries on a total of over 35 million hectares (\u3e24% of area worldwide). The first GM maize plants produced a Cry protein derived from the soil bacteriumBacillus thuringiensis (Bt), which made them resistant to European corn borer and other lepidopteran maize pests. New GM maize hybrids not only have resistance to lepidopteran pests but some have resistance to coleopteran pests and tolerance to specific herbicides. Growers are attracted to the Btmaize hybrids for their convenience and because of yield protection, reduced need for chemical insecticides, and improved grain quality. Yet, most growers worldwide still rely on traditional integrated pest management (IPM) methods to control maize pests. They must weigh the appeal of buying insect protection “in the bag” against questions regarding economics, environmental safety, and insect resistance management (IRM). Traditional management of maize insects and the opportunities and challenges presented by GM maize are considered as they relate to current and future insect-resistant products. Four countries, two that currently have commercialize Bt maize (USA and Spain) and two that do not (China and Kenya), are highlighted. As with other insect management tactics (e.g., insecticide use or tillage), GM maize should not be considered inherently compatible or incompatible with IPM. Rather, the effect of GM insect-resistance on maize IPM likely depends on how the technology is developed and used

    Genome-wide association study reveals a set of genes associated with resistance to the Mediterranean corn borer (Sesamia nonagrioides L.) in a maize diversity panel

    Get PDF

    Insights into synaptotagmin-1 CB2 domain as a putative target for new analgesic

    No full text
    SAF2015-66275-C2-R, CTQ2017-84371-P, RTI2018-097189-C2, CSIC, 201880E109, 201980E03

    Genetic variation at bx1 controls DIMBOA content in maize

    Get PDF
    The main hydroxamic acid in maize (Zea mays L.) is 2-4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA). DIMBOA confers resistance to leaf-feeding by several corn borers. Most genes involved in the DIMBOA metabolic pathway are located on the short arm of chromosome 4, and quantitative trait loci (QTLs) involved in maize resistance to leaf-feeding by corn borers have been localized to that region. However, the low resolution of QTL linkage mapping does not allow convincing proof that genetic variation at bx loci was responsible for the variability for resistance. This study addressed the following objectives: to determine the QTLs involved in DIMBOA synthesis across genetically divergent maize inbreds using eight RIL families from the nested association mapping population, to check the stability of QTLs for DIMBOA content across years by evaluating two of those RIL families in 2 years, and to test the involvement of bx1 by performing association mapping with a panel of 281 diverse inbred lines. QTLs were stable across different environments. A genetic model including eight markers explained approximately 34% of phenotypic variability across eight RIL families and the position of the largest QTL co-localizes with the majority of structural genes of the DIMBOA pathway. Candidate association analysis determined that sequence polymorphisms at bx1 greatly affects variation of DIMBOA content in a diverse panel of maize inbreds, but the specific causal polymorphism or polymorphisms responsible for the QTL detected in the region 4.01 were not identified. This result may be because the causal polymorphism(s) were not sequenced, identity is masked by linkage disequilibrium, adjustments for population structure reduce significance of causal polymorphisms or multiple causal polymorphisms affecting bx1 segregate among inbred lines.This research was supported by the National Science Foundation Plant Genome Award DBI0321467 and by research funds provided by the USDA Agricultural Research Service to MDM.Peer reviewe

    Identification of QTL for resistance to Mediterranean corn borer in a maize tropical line to improve temperate germplasm

    Get PDF
    [Background] A QTL mapping study for maize resistance to the Mediterranean corn borer (MCB) was performed with a RIL population derived from the cross B73 × CML103. To develop commercial inbreds of maize resistant to the MCB for use in Europe, it would be useful to transfer resistance from tropical germplasm like the subtropical inbred CML103 to temperate lines. The inbred B73 was chosen as representative of the Stiff Stock heterotic group, a major heterotic group used in hybrid grown in both North American and Europe. The objectives were to study the architecture of genetic factors for resistance to MCB and to check the feasibility of using marker-assisted selection (MAS) for transferring those genetic factors.[Results] Eight quantitative trait loci (QTL) were declared significant for resistance traits and eight QTL were located for agronomic traits. Alleles from CML103 at QTL significant for tunnel length could reduce tunnel length made for MCB in inbred B73 in more than 8 cm; favorable alleles for yield were also found in CML103 and no genetic correlation coefficient between tunnel length and yield was detected.[Conclusions] MAS for transferring resistance genes to corn borer attack from CML103 to B73 could be successful based on cross validation results and a negative effect on yield would not be expected.This work was supported by the National Plan for Research and Development of Spain (projects AGL2009-09611 and AGL2012-33415, both funded by the European Regional Development Fund). L.F. Samayoa acknowledges a contract JAE-Predoc from the Spanish Council for Scientific Research (CSIC). MDM acknowledges research support by USDA-ARS

    Identification of QTL for resistance to Mediterranean corn borer in a maize tropical line to improve temperate germplasm

    Get PDF
    The file Genotypic_data_147SNP_B73xCML103.xlsx contains a subset of data taken from the NAM population [Yu et al. 2008, McMullen et al. 2009] genotyping data set (phased and fully imputed genotypes at 1 cM resolution) available in http://mirrors.iplantcollaborative.org/browse/iplant/home/shared/panzea/genotypes/GBS/v23/NAM_phasedImputed_1cM_AllZeaGBSv2.3_allChrs.zip). The subset is comprised of imputed and phased genotypes at 147 single nucleotide polymorphism (SNP) markers for recombinant inbred lines (RILs) derived from the cross B73xCML103.Thanks to Panzea (https://www.panzea.org), an NSF-funded project called "Biology of Rare Alleles in Maize and its Wild Relatives", that allows open access to the entire dataset [http://mirrors.iplantcollaborative.org/browse/iplant/home/shared/panzea/genotypes/GBS/v23/NAM_phasedImputed_1cM_AllZeaGBSv2.3_allChrs.zip)] from which these data have been downloadedPeer reviewe
    corecore