Search results for "EPI"
showing 10 items of 13215 documents
Bacillus thuringiensis Vip3Aa Toxin Resistance in Heliothis virescens (Lepidoptera: Noctuidae)
2017
ABSTRACT Laboratory selection with Vip3Aa of a field-derived population of Heliothis virescens produced >2,040-fold resistance in 12 generations of selection. The Vip3Aa-selected (Vip-Sel)-resistant population showed little cross-resistance to Cry1Ab and no cross-resistance to Cry1Ac. Resistance was unstable after 15 generations without exposure to the toxin. F 1 reciprocal crosses between Vip3Aa-unselected (Vip-Unsel) and Vip-Sel insects indicated a strong paternal influence on the inheritance of resistance. Resistance ranged from almost completely recessive (mean degree of dominance [ h ] = 0.04 if the resistant parent was female) to incompletely dominant (mean h = 0.53 if the resistan…
Temperature-dependent mutational robustness can explain faster molecular evolution at warm temperatures, affecting speciation rate and global pattern…
2015
Distribution of species across the Earth shows strong latitudinal and altitudinal gradients with the number of species decreasing with declining temperatures. While these patterns have been recognized for well over a century, the mechanisms generating and maintaining them have remained elusive. Here, we propose a mechanistic explanation for temperature-dependent rates of molecular evolution that can influence speciation rates and global biodiversity gradients. Our hypothesis is based on the effects of temperature and temperature-adaptation on stability of proteins and other catalytic biomolecules. First, due to the nature of physical forces between biomolecules and water, stability of biomo…
Putting Parasemia in its phylogenetic place: a molecular analysis of the subtribe Arctiina (Lepidoptera)
2016
Despite being popular among amateur and professional lepidopterologists and posing great opportunities for evolutionary research, the phylogenetic relationships of tiger moths (Erebidae: Arctiinae) are not well resolved. Here we provide the first phylogenetic hypothesis for the subtribe Arctiina with the basic aim of clarifying the phylogenetic position of the Wood Tiger Moth Parasemia plantaginis Hübner, a model species in evolutionary ecology. We sampled 89 species in 52 genera within Arctiina s.l., 11 species of Callimorphina and two outgroup species. We sequenced up to seven nuclear genes (CAD, GAPDH, IDH, MDH, Ef1𝛼, RpS5, Wingless) and one mitochondrial gene (COI) including the barcod…
Potential impact of genetically modified Lepidoptera-resistant Brassica napus in biodiversity hotspots: Sicily as a theoretical model
2018
The general increase of the cultivation and trade of Bt transgenic plants resistant to Lepidoptera pests raises concerns regarding the conservation of animal and plant biodiversity. Demand for biofuels has increased the cultivation and importation of oilseed rape (Brassica napus L.), including transgenic lines. In environmental risk assessments (ERAs) for its potential future cultivation as well as for food and feed uses, the impact on wild Brassicaeae relatives and on non-target Lepidoptera should be assessed. Here we consider the potential exposure of butterflies as results of possible cultivation or naturalization of spilled seed in Sicily (Italy). Diurnal Lepidoptera, which are pollinat…
Molecular signatures of silencing suppression degeneracy from a complex RNA virus
2021
As genomic architectures become more complex, they begin to accumulate degenerate and redundant elements. However, analyses of the molecular mechanisms underlying these genetic architecture features remain scarce, especially in compact but sufficiently complex genomes. In the present study, we followed a proteomic approach together with a computational network analysis to reveal molecular signatures of protein function degeneracy from a plant virus (as virus-host protein-protein interactions). We employed affinity purification coupled to mass spectrometry to detect several host factors interacting with two proteins of Citrus tristeza virus (p20 and p25) that are known to function as RNA sil…
The Histone Marks Signature in Exonic and Intronic Regions Is Relevant in Early Response of Tomato Genes to Botrytis cinerea and in miRNA Regulation
2020
Research into the relationship between epigenetic regulation and resistance to biotic stresses provides alternatives for plant protection and crop improvement. To unravel the mechanisms underlying tomato responses to Botrytis cinerea, we performed a chromatin immunoprecipitation (ChIP) analysis showing the increase in H3K9ac mark along the early induced genes SlyDES, SlyDOX1, and SlyLoxD encoding oxylipin-pathway enzymes, and SlyWRKY75 coding for a transcriptional regulator of hormonal signaling. This histone mark showed a more distinct distribution than the previously studied H3K4me3. The RNAPol-ChIP analysis reflected the actual gene transcription associated with increased histone modific…
How many scales on the wings? A case study based on Colias crocea (Geoffroy, 1785) (Hexapoda: Lepidoptera, Pieridae)
2019
Abstract The covering by scales of the wings of Lepidoptera contributes to multiple functions that are critical for their survival and reproduction. In order to gain a better understanding about their distribution, we have exhaustively studied 4 specimens of Colias crocea (Geoffroy, 1785). We have quantified the sources of variability affecting scale density. The results indicate that the scale covering of butterfly wings may be remarkably heterogeneous, and that the importance of the sources of variability differs between forewings and hindwings. Thus, in forewing the greatest variability occurs between sectors, while in the hindwings it occurs between sides, with a higher density of scale…
Genetic variation and evolutionary analysis ofPepino mosaic virusin Sicily: insights into the dispersion and epidemiology
2017
Pepino mosaic virus (PepMV) is a highly infectious potexvirus that causes a severe disease in tomato (Solanum lycopersicum) crops worldwide. In Sicily, the first outbreak was detected in a single greenhouse in 2005 and it was promptly eradicated. However, in 2008, a large number of greenhouses were simultaneously affected, and it was impossible to eradicate or control the virus. This study addressed the dispersion and the genetic diversity of PepMV isolates obtained from the outbreak in Sicily, in comparison with worldwide PepMV isolates, to gain insight into the factors determining the evolution and epidemiology of the virus. A total of 1800 samples from plants with and without symptoms we…
Two consecutive Wolbachia ‐mediated mitochondrial introgressions obscure taxonomy in Palearctic swallowtail butterflies (Lepidoptera, Papilionidae)
2019
Swallowtail butterflies (Papilionidae) are among the most spectacular and well-known Lepidoptera in the European fauna, but their systematics is not fully elucidated. A notable case is that of Iphiclides feisthamelii which, after more than 180 years since description, still has a debated status, being often considered as a subspecies of Iphiclides podalirius. To elucidate the relationship between the two taxa and the evolutionary processes that led to their separation, we combine mitochondrial and nuclear DNA (mtDNA and nDNA) data, Wolbachia screening, genitalia morphology and wing UV reflectance. Our results show that the two taxa clearly differ in male and female genital morphology, male …
Adaptation to environmental stress at different timescales
2020
Environments are changing rapidly, and to cope with these changes, organisms have to adapt. Adaptation can take many shapes and occur at different speeds, depending on the type of response, the trait, the population, and the environmental conditions. The biodiversity crisis that we are currently facing illustrates that numerous species and populations are not capable of adapting with sufficient speed to ongoing environmental changes. Here, we discuss current knowledge on the ability of animals and plants to adapt to environmental stress on different timescales, mainly focusing on thermal stress and ectotherms. We discuss within-generation responses that can be fast and induced within minute…