Search results for "INSECT"
showing 10 items of 2033 documents
Knockdown of Drosophila hemoglobin suggests a role in O2 homeostasis.
2016
Almost all insects are equipped with a tracheal system, which appears to be sufficient for O2 supply even in phases of high metabolic activity. Therefore, with the exception of a few species dwelling in hypoxic habitats, specialized respiratory proteins had been considered unnecessary in insects. The recent discovery and apparently universal presence of intracellular hemoglobins in insects has remained functionally unexplained. The fruitfly Drosophila melanogaster harbors three different globin genes (referred to as glob1-3). Glob1 is the most highly expressed globin and essentially occurs in the tracheal system and the fat body. To better understand the functions of insect globins, the lev…
Divergent roles of the Drosophila melanogaster globins.
2018
In contrast to long-held assumptions, the gene repertoire of most insects includes hemoglobins. Analyses of the genome of the fruitfly Drosophila melanogaster identified three distinct hemoglobin genes (glob1, glob2, and glob3). While glob1 is predominantly associated with the tracheal system and fat body, glob2 and glob3 are almost exclusively expressed in the testis. The physiological role of globins in Drosophila is uncertain. Here, we studied the functions of the three globins in a cell culture system. Drosophila Schneider 2 (S2) cells were stably transfected with each of the three globins and the empty vector as control. Under hypoxia (1% atmospheric O2), only glob1 overexpression enha…
High Throughput Sequencing Identifies Misregulated Genes in the Drosophila Polypyrimidine Tract-Binding Protein (hephaestus) Mutant Defective in Sper…
2015
The Drosophila polypyrimidine tract-binding protein (dmPTB or hephaestus) plays an important role during spermatogenesis. The heph2 mutation in this gene results in a specific defect in spermatogenesis, causing aberrant spermatid individualization and male sterility. However, the array of molecular defects in the mutant remains uncharacterized. Using an unbiased high throughput sequencing approach, we have identified transcripts that are misregulated in this mutant. Aberrant transcripts show altered expression levels, exon skipping, and alternative 5' ends. We independently verified these findings by reverse-transcription and polymerase chain reaction (RT-PCR) analysis. Our analysis shows m…
Vitellogenin-like A–associated shifts in social cue responsiveness regulate behavioral task specialization in an ant
2018
Division of labor and task specialization explain the success of human and insect societies. Social insect colonies are characterized by division of labor, with workers specializing in brood care early and foraging later in life. Theory posits that this task switching requires shifts in responsiveness to task-related cues, yet experimental evidence is weak. Here, we show that a Vitellogenin (Vg) ortholog identified in an RNAseq study on the ant T. longispinosus is involved in this process: using phylogenetic analyses of Vg and Vg-like genes, we firstly show that this candidate gene does not cluster with the intensively studied honey bee Vg but falls into a separate Vg-like A cluster. Second…
Evaluation of a rapid immunochromatographic test for the detection of low burden Dirofilaria immitis (heartworm) in dogs and cats
2017
The performance of a rapid immunochromatographic test for the detection of Dirofilaria immitis antigens (Speed Diro™; BVT-Virbac, France) was assessed in 49 experimentally infected dogs and in 244 naturally infected animals; 142 dogs and 102 cats. In experimentally infected dogs, Speed Diro™ showed a sensitivity of 90.9% in dogs infected with one adult female worm and 100% in dogs infected with more than one female worm. Specificity was 100%. For naturally infected dogs, the Knott test and PetChek® HTWM PF served as reference methods for microfilaremia and antigenemia, respectively. All microfilaemic dogs (55/142) were positive with Speed Diro™. Importantly, none of the 21 dogs infected wit…
Extended Flight Bouts Require Disinhibition from GABAergic Mushroom Body Neurons
2019
Summary Insect flight is a complex behavior that requires the integration of multiple sensory inputs with flight motor output. Although previous genetic studies identified central brain monoaminergic neurons that modulate Drosophila flight, neuro-modulatory circuits underlying sustained flight bouts remain unexplored. Certain classes of dopaminergic and octopaminergic neurons that project to the mushroom body, a higher integrating center in the insect brain, are known to modify neuronal output based on contextual cues and thereby organismal behavior. This study focuses on how monoaminergic modulation of mushroom body GABAergic output neurons (MBONs) regulates the duration of flight bouts. O…
Non-neuronal acetylcholine involved in reproduction in mammals and honeybees.
2017
Bacteria and archaea synthesize acetylcholine (ACh). Thus, it can be postulated that ACh was created by nature roughly three billion years ago. Therefore, the wide expression of ACh in nature (i.e., in bacteria, archaea, unicellular organisms, plants, fungi, non-vertebrates and vertebrates and in the abundance of non-neuronal cells of mammals) is not surprising. The term non-neuronal ACh and non-neuronal cholinergic system have been introduced to describe the auto- and paracrine, that is, local regulatory actions of ACh in cells not innervated by neuronal cholinergic fibers and to communicate among themselves. In this way non-neuronal ACh binds to the nicotinic or muscarinic receptors expre…
Trans-generational immune priming in the mealworm beetle protects eggs through pathogen-dependent mechanisms imposing no immediate fitness cost for t…
2018
8 pages; International audience; Immune-challenged mothers can improve their offspring immunity through trans-generational immune priming (TGIP). In insects, TGIP endows the offspring with lifetime immunity, including the eggs, which are likely exposed soon after maternal infection. Egg protection may rely on the transfer of maternal immune effectors to the egg or/and the induction of egg immune genes. These respective mechanisms are assumed to have early-life fitness costs of different magnitude for the offspring. We provide evidence in the mealworm beetle Tenebrio molitor that enhanced egg immunity following a maternal immune challenge is achieved by both of these mechanisms but in a path…
Apoptotic Activity of MeCP2 Is Enhanced by C-Terminal Truncating Mutations.
2016
Methyl-CpG binding protein 2 (MeCP2) is a widely abundant, multifunctional protein most highly expressed in post-mitotic neurons. Mutations causing Rett syndrome and related neurodevelopmental disorders have been identified along the entire MECP2 locus, but symptoms vary depending on mutation type and location. C-terminal mutations are prevalent, but little is known about the function of the MeCP2 C-terminus. We employ the genetic efficiency of Drosophila to provide evidence that expression of p.Arg294* (more commonly identified as R294X), a human MECP2 E2 mutant allele causing truncation of the C-terminal domains, promotes apoptosis of identified neurons in vivo. We confirm this novel find…
The Gut Entomotype of Red Palm Weevil Rhynchophorus ferrugineus Olivier (Coleoptera: Dryophthoridae) and Their Effect on Host Nutrition Metabolism
2017
For invasive insects, the potential roles of gut microbiota in exploiting new food resources and spreading remain elusive. Red palm weevil (RPW), Rhynchophorus ferrugineus Olivier, is an invasive destructive pest which feeds on nutrient-poor tender tissues and has caused extensive mortality of palm trees. The microbes associated with insects can improve their nutrition assimilation. However, experimental evidence on the interactions between RPW and its gut microbiota is still absent. The aim of this study is to determine the dynamics changes and the bacterial entomotype in the RPW gut and its potential physiological roles. Here, we confirmed RPW harbors a complex gut microbiota mainly const…