Juvenile hormone (JH) synthesized and released from endocrine gland corpus allatum (CA) plays an important role in insect metamorphosis, vitellogenesis and reproduction. Glutamate is a major neurotransmitter in the nervous system and its activated receptors possess excitatory and inhibitory forms in muscle fibers of invertebrates. Previously, we have shown that the rise of intracellular calcium through excitatory glutamate receptors, N-methyl-d-aspartate (NMDA) and non-NMDA-type channels stimulates JH synthesis in the cockroach, Diploptera punctata. Here, we demonstrate the occurrence of inhibitory chloride permeable glutamate (GluCl) receptors on CA cell membranes. Application of the GluCl channel activators, ibotenic acid (Ibo) and ivermectin, but not gamma-aminobutyric acid caused a decline in JH synthesis in glands of either high or low activity during the gonadotrophic cycle. Also, while recording the membrane potential of the isolated whole CA glands intracellularly, Ibo induced a hyperpolarizated response. Both changes in the membrane potential and inhibition of JH synthesis could be abolished by the application of the chloride channel blocker picrotoxin. Finally, we found both excitatory and inhibitory glutamate receptors cause antagonistic effects on rates of JH synthesis. These results indicate a novel function of GluCl channels in the inhibition of JH synthesis that could be a potential pathway for developing a new generation of insecticides.
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http://dx.doi.org/10.1016/j.ibmb.2005.06.004 | DOI Listing |
J Exp Biol
January 2025
University of Guelph, 50 Stone Rd E, Guelph, N1G 2M7, Canada.
The timing of metamorphosis and settlement is critical for the survival and reproductive success of marine animals with biphasic life cycles. Thyroid hormones (THs) regulate developmental timing in diverse groups of chordates, including the regulation of metamorphosis in amphibians, teleosts, lancelets, tunicates, and lampreys. Recent evidence suggests a role for TH regulation of metamorphosis outside of the chordates, including echinoderms, annelids, and molluscs.
View Article and Find Full Text PDFJ Agric Food Chem
January 2025
College of Plant Protection, Hebei Agricultural University, Baoding, Hebei 071000, P. R. China.
is a major migratory invasive pest and is of global concern. Vitellogenesis, a crucial process for population multiplication in oviparous insects, is regulated by endocrine hormones. In this study, three primary responders to JH signaling, the JH receptor gene , and the downstream transcription factor and , were first cloned and identified.
View Article and Find Full Text PDFInsect Biochem Mol Biol
December 2024
Department of Entomology, College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY, 40546, USA. Electronic address:
Chemosphere
December 2024
Aquatic Science Center, Wisconsin Sea Grant, University of Wisconsin - Madison, Madison, WI, USA. Electronic address:
Aquatic herbicides are commonly used to control a variety of non-native plants. One common active ingredient used in commercial herbicide formulations globally is 2,4-dichlorophenoxyacetic acid (2,4-D). Though 2,4-D is used in aquatic ecosystems, no studies have investigated cellular, biochemical, and transcriptional effects or mechanisms of 2,4-D exposure on fathead minnows (Pimephales promelas) throughout juvenile development.
View Article and Find Full Text PDFCurr Issues Mol Biol
November 2024
Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081, China.
In this study, we investigated the regulatory roles of the () gene in the reproductive process of female . Its total cDNA length was 1848 bp, encoding for 460 amino acids. It contained conserved domains typical of epoxide hydrolases, such as the Abhydrolase family domain, the EHN epoxide hydrolase superfamily domain, and the "WWG" and "HGWP" motifs.
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