Search results for "INSECTS"
showing 10 items of 123 documents
Electrostatic Tuning of the Ligand Binding Mechanism by Glu27 in Nitrophorin 7
2018
AbstractNitrophorins (NP) 1–7 are NO-carrying heme proteins found in the saliva of the blood-sucking insect Rhodnius prolixus. The isoform NP7 displays peculiar properties, such as an abnormally high isoelectric point, the ability to bind negatively charged membranes, and a strong pH sensitivity of NO affinity. A unique trait of NP7 is the presence of Glu in position 27, which is occupied by Val in other NPs. Glu27 appears to be important for tuning the heme properties, but its influence on the pH-dependent NO release mechanism, which is assisted by a conformational change in the AB loop, remains unexplored. Here, in order to gain insight into the functional role of Glu27, we examine the ef…
Aplicación de la topología molecular a la predicción y optimización de la actividad repelente de mosquitos de derivados de la N-acylpiperidina
2014
Se ha construido un modelo topológico-matemático con el fin de seleccionar nuevos repelentes de mosquito derivados de la N-acylpiperidina. Para ello se ha empleado la técnica estadística del análisis de regresión multilineal. Los compuestos empleados en la elaboración del modelo han sido caracterizados por medio de índices topológicos. Finalmente, se ha obtenido un modelo de 5 variables capaz de predecir los tiempos de protección de diversos repelentes de mosquitos derivados de la N-acylpiperidina (R2=0.8457 y Q2= 0.7486). El modelo ha sido validado mediante validación cruzada interna de tipo leave-one-out y un test de aleatoriedad. Los resultados han confirmado la capacidad del modelo para…
Structural cuticular proteins in termite queens
1978
0305-0491 (Print) Journal Article; The abdominal cuticle from queens of two termite species, Cubitermes fungifaber and Macrotermes bellicosus, has been investigated with respect to changes occurring during development of physogastry. The following properties have been determined: 1. Relative content of protein and chitin and the percentage of easily extracted protein. 2. Number of proteins separated by electrophoresis and their molecular weights. 3. Amino acid compositions of the intertergal and pleural membranes and of the neosclerites in M. bellicosus. The intertergal and pleural membranes appear to be typical "soft" cuticles, and the neosclerites must also be considered "soft" cuticles, …
Vertical transmission of naturally occurring Bunyamwera and insect-specific flavivirus infections in mosquitoes from islands and mainland shores of L…
2018
Background Many arboviruses transmitted by mosquitoes have been implicated as causative agents of both human and animal illnesses in East Africa. Although epidemics of arboviral emerging infectious diseases have risen in frequency in recent years, the extent to which mosquitoes maintain pathogens in circulation during inter-epidemic periods is still poorly understood. This study aimed to investigate whether arboviruses may be maintained by vertical transmission via immature life stages of different mosquito vector species. Methodology We collected immature mosquitoes (egg, larva, pupa) on the shores and islands of Lake Baringo and Lake Victoria in western Kenya and reared them to adults. Mo…
Diversity and composition of the microbiome associated with eggs of the Southern green stinkbug, Nezara viridula (Hemiptera: Pentatomidae).
2022
Although microbial communities of insects from larval to adult stage have been increasingly investigated in recent years, little is still known about the diversity and composition of egg-associated microbiomes. In this study, we used high-throughput amplicon sequencing and quantitative PCR to get a better understanding of the microbiome of insect eggs and how they are established using the Southern green stinkbug Nezara viridula (L.) (Hemiptera: Pentatomidae) as a study object. First, to determine the bacterial community composition, egg masses from two natural populations in Belgium and Italy were examined. Subsequently, microbial community establishment was assessed by studying stinkbug e…
A Mushroom Bodies inspired spiking network for classification and sequence learning
2015
Sequence learning is a complex capability shown by living beings, able to extract information from the environment. Looking into the insect world, there are several examples where the presentation time of specific stimuli is considered to select the proper behavioural response. On the basis of previously developed neural models for sequence learning, inspired by the Drosophila melanogaster, a new formalization of key brain structures involved in the process is here provided. The input classification is performed through resonant neurons, stimulated by the complex dynamics generated in a lattice of recurrent spiking neurons modelling the Mushroom Bodies neuropile in the insect brain. The net…
Effect of dual biotic stress on plant volatile synomones used by egg parasitoids
2014
Studies on semiochemical communication have demonstrated that broad bean plant, Vicia faba, emits volatile synomones induced by feeding and oviposition activities of the southern green stink bug, Nezara viridula, which recruit the egg parasitoid Trissolcus basalis. However plants growing in agro-ecosystems can be attacked by several herbivore species that could affect both above and belowground plant tissues with possible consequences for parasitoid recruitment. For example, broad bean plants can also be attacked by the leaf weevil, Sitona lineatus, and simultaneous attacks by the southern green stink bug and the leaf weevil can occur in agro- ecosystems. The purpose of this work was to inv…
Massive presence of insertion sequences in the genome of SOPE, the primary endosymbiont of the rice weevil Sitophilus oryzae
2008
Bacteria that establish an obligate intracellular relationship with eukaryotic hosts undergo an evolutionary genomic reductive process. Recent studies have shown an increase in the number of mobile elements in the first stage of the adaptive process towards intracellular life, although these elements are absent in ancient endosymbionts. Here, the genome of SOPE, the obligate mutualistic endosymbiont of rice weevils, was used as a model to analyze the initial events that occur after symbiotic integration. During the first phases of the SOPE genome project, four different types of insertion sequence (IS) elements, belonging to well-characterized IS families from γ-proteobacteria, were identif…
World revision of the genus Encyrtoscelio Dodd (Hymenoptera: Scelionidae)
1995
The genus Encyrtoscelio Dodd is revised. E. apterus (Szelényi), E. mirissimus Dodd, E. turneri Waterston are redescribed, and six new species are described: E. cydni Caleca, E. japonicus Caleca, E. mediterraneus Caleca, E. miroides Caleca, E. spuratus Caleca and E. undecim Caleca. A key to separate females is presented, and is based on the number of antennomeres and claval sensillar formula, mandibular spurs and teeth, palpal formula and clypeus, and some cephalic characters. Morphological adaptations of the head and mandibles are discussed in relation to host habitat and oviposition site. Information on host associations, habitat preference, seasonal and daily occurrence of some species a…
Dinosaur bonebed amber from an original swamp forest soil
2021
AbstractDinosaur bonebeds with amber content, yet scarce, offer a superior wealth and quality of data on ancient terrestrial ecosystems. However, the preserved palaeodiversity and/or taphonomic characteristics of these exceptional localities had hitherto limited their palaeobiological potential. Here we describe the amber from the Lower Cretaceous dinosaur bonebed of Ariño (Teruel, Spain) using a multidisciplinary approach. Amber is found in both a root layer with amber strictly in situ and a litter layer namely composed of aerial pieces unusually rich in bioinclusions, encompassing 11 insect orders, arachnids, and a few plant and vertebrate remains, including a feather. Additional palaeont…