Search results for "RVA"

Resemblance of a model species and its mimic: Response to Bury and Cichoń

2018

Toxicity and Binding Studies of Bacillus thuringiensis Cry1Ac, Cry1F, Cry1C, and Cry2A Proteins in the Soybean Pests Anticarsia gemmatalis and Chryso…

2017

ABSTRACT Anticarsia gemmatalis (velvetbean caterpillar) and Chrysodeixis includens (soybean looper, formerly named Pseudoplusia includens ) are two important defoliating insects of soybeans. Both lepidopteran pests are controlled mainly with synthetic insecticides. Alternative control strategies, such as biopesticides based on the Bacillus thuringiensis (Bt) toxins or transgenic plants expressing Bt toxins, can be used and are increasingly being adopted. Studies on the insect susceptibilities and modes of action of the different Bt toxins are crucial to determine management strategies to control the pests and to delay outbreaks of insect resistance. In the present study, the susceptibilitie…

Within trophic level shifts in collagen-carbonate stable carbon isotope spacing are propagated by diet and digestive physiology in large mammal herbi…

2018

Stable carbon isotope analyses of vertebrate hard tissues such as bones, teeth, and tusks provide information about animal diets in ecological, archeological, and paleontological contexts. There is debate about how carbon isotope compositions of collagen and apatite carbonate differ in terms of their relationship to diet, and to each other. We evaluated relationships between δ13Ccollagen and δ13Ccarbonate among free-ranging southern African mammals to test predictions about the influences of dietary and physiological differences between species. Whereas the slopes of δ13Ccollagen–δ13Ccarbonate relationships among carnivores are ≤1, herbivore δ13Ccollag…

Staying cool: preadaptation to temperate climates required for colonising tropical alpine-like environments.

2018

Plant species tend to retain their ancestral ecology, responding to temporal, geographic and climatic changes by tracking suitable habitats rather than adapting to novel conditions. Nevertheless, transitions into different environments or biomes still seem to be common. Especially intriguing are the tropical alpine-like areas found on only the highest mountainous regions surrounded by tropical environments. Tropical mountains are hotspots of biodiversity, often with striking degrees of endemism at higher elevations. On these mountains, steep environmental gradients and high habitat heterogeneity within small spaces coincide with astounding species diversity of great conservation value. The …

Specific binding of Bacillus thuringiensis Cry1Ea toxin, and Cry1Ac and Cry1Fa competition analyses in Anticarsia gemmatalis and Chrysodeixis include…

2019

AbstractAnticarsia gemmatalis (velvetbean caterpillar) and Chrysodeixis includens (soybean looper) are two important defoliation pests of soybeans. In the present study, we have investigated the susceptibility and brush border membrane-binding properties of both species to Bacillus thuringiensis Cry1Ea toxin. Bioassays performed in first-instar larvae demonstrated potent activity against both soybean pests in terms of mortality or practical mortality. Competition-binding studies carried out with 125Iodine-labelled Cry1Ea, demonstrated the presence of specific binding sites on the midgut brush border membrane vesicles (BBMV) of both insect species. Heterologous competition-binding experiment…

Genetic Basis of Body Color and Spotting Pattern in Redheaded Pine Sawfly Larvae (Neodiprion lecontei)

2018

Abstract Pigmentation has emerged as a premier model for understanding the genetic basis of phenotypic evolution, and a growing catalog of color loci is starting to reveal biases in the mutations, genes, and genetic architectures underlying color variation in the wild. However, existing studies have sampled a limited subset of taxa, color traits, and developmental stages. To expand the existing sample of color loci, we performed QTL mapping analyses on two types of larval pigmentation traits that vary among populations of the redheaded pine sawfly (Neodiprion lecontei): carotenoid-based yellow body color and melanin-based spotting pattern. For both traits, our QTL models explained a substan…

Role of Bacillus thuringiensis Cry1A toxins domains in the binding to the ABCC2 receptor from Spodoptera exigua

2018

Abstract Cry proteins from Bacillus thuringiensis (Bt) have been used to control insect pests either as formulated sprays or as in Bt-crops. However, field-evolved resistance to Bt proteins is threatening the long-term use of Bt products. The SeABCC2 locus has been genetically linked to resistance to a Bt bioinsecticide (Xentari™) in Spodoptera exigua (a mutation producing a truncated form of the transporter lacking an ATP binding domain was found in the resistant insects). Here, we investigated the role of SeABCC2 in the mode of action of Cry1Aa, Cry1Ab, Cry1Ac, Cry1Ca, and two Cry1A-1Ca hybrids by expressing the receptor in Sf21 and HEK293T cell lines. Cell toxicity assays showed that Sf2…

An integrative identification guide to the Hydrozoa (Cnidaria) of Bocas del Toro, Panama

2018

This work is the first attempt to assess the biodiversity of the Hydrozoa in the Archipiélago de Bocas del Toro (Panamá, Caribbean Sea) using morphology and molecular taxonomy, and to produce field identification tools to help future identification and monitoring efforts in the area. We sampled, identified, vouchered, and barcoded 112 specimens of Hydrozoa from shallow coastal waters (0–22 m depth) in the Archipiélago de Bocas del Toro. The specimens belong to 70 taxa, of which 53 were identified at the species level, and 17 were identified at the genus or family level. We produced 64 sequences of the large ribosomal subunit of the mitochondrial RNA (mt lsu-rRNA, 16S), the genetic marker ge…

When Choice Makes Sense: Menthol Influence on Mating, Oviposition and Fecundity in Drosophila melanogaster

2016

International audience; The environment to which insects have been exposed as larvae and adults can affect subsequent behaviors, such as mating, oviposition, food preference or fitness. Experience can change female preference for oviposition, particularly in phytophagous insects. In Drosophila melanogaster, females avoid laying eggs on menthol rich-food when given the choice. Exposure to menthol during larval development reduces this aversion. However, this observation was not reproduced in the following generation. Recently, we have shown that oviposition-site preference (OSP) differs between wild type D. melanogaster lines freely or forcibly exposed to menthol. After 12 generations, menth…

Conservation of the endangered Mediterranean tortoise Testudo hermanni hermanni: The contribution of population genetics and historical demography

2016

International audience; Estimating the genetic variation and demographic trends of species in decline is of major concern in conservation genetics. This study contributes to understanding how historical and anthropogenic factors shape the distribution of current genetic diversity in one of the most endangered reptiles in Western Europe, the Hermann's tortoise Testudo hermanni hermanni. We used 17 microsatellite loci, chosen from a pyrosequencing library specifically developed for the subspecies to genotype eight populations distributed over about 30 sample localities covering almost the entire geographic distribution of the sub-species. The population genetic results reflect a very strong g…