Search results for "INSECT"
showing 10 items of 2033 documents
Neuropeptidome regulation after baculovirus infection. A focus on proctolin and its relevance in locomotion and digestion
2020
AbstractBaculoviruses constitute a large group of invertebrate DNA viruses, predominantly infecting larvae of the insect order Lepidoptera. During a baculovirus infection, the virus spreads throughout the insect body producing a systemic infection in multiple larval tissues. Some behavioral and physiological changes in lepidopteran larvae have been described following a baculovirus infection and those changes could be connected with alterations in the host’s central nervous system (CNS). As a main component of the CNS, neuropeptides are small protein-like molecules functioning as neurohormones, neurotransmitters or neuromodulators. These peptides are involved in regulating animal physiology…
The evolutionary dynamics of adaptive virginity, sex-allocation and altruistic helping in haplodiploid animals
2018
In haplodiploids, females can produce sons from unfertilized eggs without mating. However, virgin reproduction is usually considered to be a result of a failure to mate, rather than an adaptation. Here, we build an analytical model for evolution of virgin reproduction, sex-allocation, and altruistic female helping in haplodiploid taxa. We show that when mating is costly (e.g., when mating increases predation risk), virginity can evolve as an adaptive female reproductive strategy. Furthermore, adaptive virginity results in strongly divergent sex-ratios in mated and virgin queen nests ("split sex ratios"), which promotes the evolution of altruistic helping by daughters in mated queen nests. H…
Nucleotide sequence of an adult-specific cuticular protein gene from the beetle Tenebrio molitor: effects of 20-hydroxyecdysone on mRNA accumulation.
1993
0962-1075 (Print) Journal Article Research Support, Non-U.S. Gov't; The accumulation of transcripts from two adult-specific cuticular genes (ACP-20 and ACP-22) is shown to be modified after addition of exogenous 20-hydroxyecdysone. In the continuous presence of high levels of the hormone, the expression of ACP-20 gene is significantly weaker than that of untreated controls, while ACP-22 expression is 2.5-fold increased. During active synthesis of the ACP messages, a 0.5 microg 20-hydroxyecdysone injection causes a rapid 2-fold increase in ACP-22 mRNA and is not able to repress ACP-20 mRNA accumulation. We conclude that these genes whose transcripts appear in an almost coordinated manner in …
A proctolin-like peptide is regulated after baculovirus infection and mediates in caterpillar locomotion and digestion
2022
Baculoviruses constitute a large group of invertebrate DNA viruses, predominantly infecting larvae of the insect order Lepidoptera. During a baculovirus infection, the virus spreads throughout the insect body producing a systemic infection in multiple larval tissues, included the central nervous system (CNS). As a main component of the CNS, neuropeptides are small protein-like molecules functioning as neurohormones, neurotransmitters, or neuromodulators. These peptides are involved in regulating animal physiology and behavior and could be altered after baculovirus infection. In this study, we have investigated the effect of Spodoptera exigua multiple nucleopolyhedrovirus (SeMNPV) infection …
A Protein Nuclear Extract fromD. melanogasterLarval Tissues
2008
Preparation of protein nuclear extracts is often the first step to study in vitro biological processes occurring in the nucleus of the eukaryotic cell. Nuclear extracts have been extensively used in different model organisms to identify and study protein function in nuclei. Drosophila embryos can be collected in large quantities and have been the source of choice for the production of protein nuclear extracts. However, most of Drosophila in vivo studies on protein function are conducted in larval tissues. Here we report a new method to produce highly stable large-scale protein nuclear extracts from whole Drosophila larvae that are suited for a variety of biochemical analyses.
Nuevos fármacos inspirados en Annonáceas
2014
Los metabolitos secundarios activos (MSA) juegan un papel importante en el descubrimiento de nuevos medicamentos. Moléculas naturales con esqueletos complejos, tales como las estatinas aisladas de Aspergillus terreus, o las acetogeninas específicas de la familia Annonaceae, no hubieran podido ser inventadas en ningún laboratorio. Los MSA aislados en Annonaceae, especialmente las acetogeninas y los alcaloides isoquinoleínicos, pueden ser considerados como fuente constante de inspiración para químicos, farmacólogos y para todos los investigadores interesados en el descubrimiento de una nueva familia de medicamentos. Active secondary metabolites (ASM) play a highly significant role in the drug…
Clock genes and photoperiodism in the aphid Acyrthosiphon pisum
2017
Aphids have a strong seasonal response, namely the development of a sexual morphs triggered by the shortening of photoperiod in autumn that produce an overwintering egg in which an embryonic diapause takes place. From this egg, an asexual parthenogenetic female emerges giving way to the asexual phase of the aphid life cycle in which several asexual generations occur. Based on the response to short photoperiods, two strains of aphids can be found: the holocyclic develop the seasonal response under short photoperiods, while the anholocyclic do not. The sequencing of the genome of the pea aphid Acyrthosiphon pisum places this species as an excellent model to investigate the the involvement of …
De novo Synthesis of Chemical Defenses in an Aposematic Moth
2018
Many animals protect themselves from predation with chemicals, both self-made or sequestered from their diet. The potential drivers of the diversity of these chemicals have been long studied, but our knowledge of these chemicals and their acquisition mode is heavily based on specialist herbivores that sequester their defenses. The wood tiger moth (Arctia plantaginis, Linnaeus, 1758) is a well-studied aposematic species, but the nature of its chemical defenses has not been fully described . Here, we report the presence of two methoxypyrazines, 2-sec-butyl-3-methoxypyrazine and 2-isobutyl-3-methoxypyrazine, in the moths’ defensive secretions. By raising larvae on an artificial diet, we confir…
Lipocalins in Arthropod Chemical Communication.
2021
Abstract Lipocalins represent one of the most successful superfamilies of proteins. Most of them are extracellular carriers for hydrophobic ligands across aqueous media, but other functions have been reported. They are present in most living organisms including bacteria. In animals they have been identified in mammals, molluscs, and arthropods; sequences have also been reported for plants. A subgroup of lipocalins, referred to as odorant-binding proteins (OBPs), mediate chemical communication in mammals by ferrying specific pheromones to the vomeronasal organ. So far, these proteins have not been reported as carriers of semiochemicals in other living organisms; instead chemical communicatio…
Tempo and mode of early gene loss in endosymbiotic bacteria from insects
2006
Abstract Background Understanding evolutionary processes that drive genome reduction requires determining the tempo (rate) and the mode (size and types of deletions) of gene losses. In this study, we analysed five endosymbiotic genome sequences of the gamma-proteobacteria (three different Buchnera aphidicola strains, Wigglesworthia glossinidia, Blochmannia floridanus) to test if gene loss could be driven by the selective importance of genes. We used a parsimony method to reconstruct a minimal ancestral genome of insect endosymbionts and quantified gene loss along the branches of the phylogenetic tree. To evaluate the selective or functional importance of genes, we used a parameter that meas…