Search results for "VIP"

Data from: Phylogenomics of Lophotrochozoa with consideration of systematic error

2016

Phylogenomic studies have improved understanding of deep metazoan phylogeny and show promise for resolving incongruences among analyses based on limited numbers of loci. One region of the animal tree that has been especially difficult to resolve, even with phylogenomic approaches, is relationships within Lophotrochozoa (the animal clade that includes molluscs, annelids, and flatworms among others). Lack of resolution in phylogenomic analyses could be due to insufficient phylogenetic signal, limitations in taxon and/or gene sampling, or systematic error. Here, we investigated why lophotrochozoan phylogeny has been such a difficult question to answer by identifying and reducing sources of sys…

Inbreeding does not alter the response to an experimental heat wave in a freshwater snail

2019

Global climate change affects natural populations of many species by increasing the average temperature and the frequency of extreme weather events (e.g. summer heat waves). The ability of organisms to cope with these environmental changes can, however, depend on their genetic properties. For instance, genetic load owing to inbreeding could alter organisms’ responses to climate change-mediated environmental changes but such effects are often overlooked. We investigated the effects of an experimental heat wave (25°C versus 15°C) on life history (reproduction, size) and constitutive immune defence traits (phenoloxidase-like and antibacterial activity of haemolymph) in relation to inbreeding b…

Contribution to the knowledge of North-American species Hyperomyzus subgenus Neonasonovia (Aphididae, Aphidinae, Macrosiphini)

2017

American specimens of the Hyperomyzus subgenus Neonasonovia conserved in the collections of the Museum national d’Histoire naturelle (Paris, France) and the Natural History Museum (London, United Kingdom), have been studied. Data to complement previous descriptions of apterous and alate viviparous females of H. nabali and of apterous viviparae of H. nigricornis, H. inflatus, H. niger and H. pullatus , are presented. Apterous and alate virginogeniae females of H. nigricornis, alate viviparous females of H. inflatus, H. niger and H. pullatus, plus oviparous females of H. nabali , are described for the first time. The morphological and biological variability of H. pullatus is discussed. An ide…

Characterisation of the structure-function relationship of the Bacillus thuringiensis Vip3A insecticidal proteins

2017

L'agricultura contemporània exigeix cada cop més un ús sostenible d’agroquímics per tal de reduir l'impacte ambiental i el risc per la salut del consumidor. Alguns bacteris entomopatògens produeixen proteïnes insecticides que s'acumulen en cossos d'inclusió o cristalls paraesporales (com ara les proteïnes Cry i Cyt), així com proteïnes insecticides que són secretades al medi de cultiu. Entre les últimes, hi ha les proteïnes Vip, que es divideixen en quatre famílies d'acord amb la seva identitat d'aminoàcids. Les proteïnes Vip1 i Vip2 actuen com toxines binàries i són tòxiques per a alguns coleòpters i hemípters. Per la família de les Vip4, que és l’última família de proteïnes Vip descoberta…

A Genomic and Proteomic Approach to Identify and Quantify the Expressed

2018

The combined analysis of genomic and proteomic data allowed us to determine which cry and vip genes are present in a Bacillus thuringiensis (Bt) isolate and which ones are being expressed. Nine Bt isolates were selected from Spanish collections of Bt based on their vip1 and vip2 gene content. As a first step, nine isolates were analyzed by PCR to select those Bt isolates that contained genes with the lowest similarity to already described vip1 and vip2 genes (isolates E-SE10.2 and O-V84.2). Two selected isolates were subjected to a combined genomic and proteomic analysis. The results showed that the Bt isolate E-SE10.2 codifies for two new vegetative proteins, Vip2Ac-like_1 and Sip1Aa-like_…

Encapsulation of the Bacillus thuringiensis secretable toxins Vip3Aa and Cry1Ia in Pseudomonas fluorescens

2013

Vip3A and Cry1I toxins are secreted during the vegetative growth of Bacillus thuringiensis. Vip3A toxins do not share homology to the crystal (Cry) proteins and are active against a different spectrum of lepidopteran species. Cry1I toxins share similarity with the Cry1 protein group but do not accumulate in the parasporal crystal. Since Vip3A and Cry1I toxins are released from the cell, they are excluded from biological formulates based on spores and crystals of B. thuringiensis. As an approach to obtain novel sprayable insecticides containing Vip3 or Cry1I toxins, Vip3Aa and Cry1Ia proteins were expressed in Pseudomonas fluorescens. This bacterium, non-pathogenic to animals or plants, can …

Kivipelto

Data from: Plant – herbivorous beetle networks: molecular characterization of trophic ecology within a threatened steppic environment

2015

DNA barcoding facilitates many evolutionary and ecological studies, including the examination of the dietary diversity of herbivores. In this study, we present a survey of ecological associations between herbivorous beetles and host plants from seriously threatened European steppic grasslands. We determined host plants for the majority (65%) of steppic leaf beetles (55 species) and weevils (59) known from central Europe using two barcodes (trnL and rbcL) and two sequencing strategies (Sanger for mono/oligophagous species and Illumina for polyphagous taxa). To better understand the ecological associations between steppic beetles and their host plants, we tested the hypothesis that leaf beetl…

Hypoxia and hypothermia as rival agents of selection driving the evolution of viviparity in lizards

2017

[Aim]: The evolution of key innovations promotes adaptive radiations by opening access to new ecological opportunity. The acquisition of viviparity (live-bearing reproduction) has emerged as one such innovation explaining reptile proliferations into extreme climates. By evolving viviparity, females provide embryos with internally stable environments to complete development. The classical hypothesis suggests that natural selection for viviparity arises from low temperatures in cold climates, which promote prolonged egg retention in the mother's body. An alternative hypothesis proposes that declines in atmospheric oxygen at high elevations create natural selection for embryo retention to prov…

Les contextualisations de la description du français dans les grammaires étrangères : présentation

2014

International audience