Neotrop Entomol
December 2024
Seed beetles spend most of their lives within the seeds of host plants belonging to the Fabaceae family. Evidence suggests the cues that mediate pre-oviposition behaviour in Zabrotes subfasciatus (Boheman) are volatile organic compounds (VOCs) emitted by the seeds and suggests differential abilities in environment sensing between sexes. Here, we tested whether VOCs from different legume species trigger different levels of attraction, whether females and males differ in their ability to respond to VOCs, and whether the seeds promoting different behaviours feature singular VOCs.
View Article and Find Full Text PDFThe brain of adult honeybee (Apis mellifera) workers is larger than that of queens, facilitating behavioural differentiation between the castes. This brain diphenism develops during the pharate-adult stage and is driven by a caste-specific gene expression cascade in response to unique hormonal milieus. Previous molecular screening identified minibrain (mnb; DYRK1A) as a potential regulator in this process.
View Article and Find Full Text PDFEcotoxicology
October 2024
The stingless bee Frieseomelitta varia Lepeletier 1836 (Hymenoptera: Apidae) is an essential pollinator in natural and agricultural ecosystems in the Neotropical region. However, these bees may be exposed to pesticides during foraging, which can affect both individuals and their colonies. One example comes from the use of pyraclostrobin (a fungicide) and thiamethoxam (an insecticide) for pest control in pepper crops, which F.
View Article and Find Full Text PDFIntroduction: Chemotherapy-induced neuropathic pain (CINP) is one of the main adverse effects of chemotherapy treatment. At the spinal level, CINP modulation involves glial cells that upregulate Toll-like receptor 4 (TLR4) and signaling pathways, which can be activated by pro-inflammatory mediators as the high mobility group box-1 (HMGB1).
Objective: To evaluate the spinal role of HMGB1 in the paclitaxel-induced neuropathic pain via receptor for advanced glycation end products (RAGE) and TLR4 activation expressed in glial cells.
J Insect Physiol
May 2024
Farnesol, a sesquiterpene found in all eukaryotes, precursor of juvenile hormone (JH) in insects, is involved in signalling, communication, and antimicrobial defence. Farnesol is a compound of floral volatiles, suggesting its importance in pollination and foraging behaviour. Farnesol is found in the resin of Baccharis dracunculifolia, from which honeybees elaborate the most worldwide marketable propolis.
View Article and Find Full Text PDFBiochim Biophys Acta Gene Regul Mech
September 2021
Brain differential morphogenesis in females is one of the major phenotypic manifestations of caste development in honey bees. Brain diphenism appears at the fourth larval phase as a result of the differential feeding regime developing females are submitted during early phases of larval development. Here, we used a forward genetics approach to test the early brain molecular response to differential feeding leading to the brain diphenism observed at later developmental phases.
View Article and Find Full Text PDFGlucocorticoids (GCs) are used for acute respiratory distress syndrome (ARDS) to improve or prevent lung injury. The mechanisms underlying the effects of GCs involve inadequate GC-receptor (GR)-mediated downregulation of pro-inflammatory factors despite elevated levels of cortisol. Within this context, knowledge of the transcriptional pattern of the GR gene in response to variations in physiological parameters may shed light on this issue.
View Article and Find Full Text PDFAdult honey bee queens and workers drastically differ in ovary size. This adult ovary phenotype difference becomes established during the final larval instar, when massive programmed cell death leads to the degeneration of 95-99% of the ovariole anlagen in workers. The higher juvenile hormone (JH) levels in queen larvae protect the ovaries against such degeneration.
View Article and Find Full Text PDFBackground: The insect exoskeleton provides shape, waterproofing, and locomotion via attached somatic muscles. The exoskeleton is renewed during molting, a process regulated by ecdysteroid hormones. The holometabolous pupa transforms into an adult during the imaginal molt, when the epidermis synthe3sizes the definitive exoskeleton that then differentiates progressively.
View Article and Find Full Text PDFThe differential feeding regimes experienced by the queen and worker larvae of the honeybee Apis mellifera shape a complex endocrine response cascade that ultimately gives rise to differences in brain morphologies. Brain development analyzed at the morphological level from the third (L3) through fifth (L5) larval instars revealed an asynchrony between queens and workers. In the feeding phase of the last larval instar (L5F), two well-formed structures, pedunculi and calyces, are identifiable in the mushroom bodies of queens, both of which are not present in workers until a later phase (spinning phase, L5S).
View Article and Find Full Text PDFBeyond the physiological and behavioural, differences in appendage morphology between the workers and queens of Apis mellifera are pre-eminent. The hind legs of workers, which are highly specialized pollinators, deserve special attention. The hind tibia of worker has an expanded bristle-free region used for carrying pollen and propolis, the corbicula.
View Article and Find Full Text PDFEcdysteroids regulate many aspects of insect physiology after binding to a heterodimer composed of the nuclear hormone receptor proteins ecdysone receptor (EcR) and ultraspiracle (Usp). Several lines of evidence have suggested that the latter also plays important roles in mediating the action of juvenile hormone (JH) and, thus, integrates signaling by the two morphogenetic hormones. By using an RNAi approach, we show here that Usp participates in the mechanism that regulates the progression of pupal development in Apis mellifera, as indicated by the observed pupal developmental delay in usp knocked-down bees.
View Article and Find Full Text PDFThe caste-specific regulation of vitellogenin synthesis in the honeybee represents a problem with many yet unresolved details. We carried out experiments to determine when levels of vitellogenin are first detected in hemolymph of female castes of Apis mellifera, and whether juvenile hormone and ecdysteroids modulate this process. Vitellogenin levels were measured in hemolymph using immunological techniques.
View Article and Find Full Text PDFSocial life is prone to invasion by microorganisms, and binding of ferric ions by transferrin is an efficient strategy to restrict their access to iron. In this study, we isolated cDNA and genomic clones encoding an Apis mellifera transferrin (AmTRF) gene. It has an open reading frame (ORF) of 2136 bp spread over nine exons.
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