entomology

  • Phytoecdysteroids, Plant-Derived Ecdysteroids Wiki

    Phytoecdysteroids, Plant-Derived Ecdysteroids Wiki

    Phytoecdysteroids are plant-derived ecdysteroids. Phytoecdysteroids are a class of chemicals that plants synthesize for defense against phytophagous (plant eating) insects. These compounds are mimics of hormones used by arthropods in the molting process known as ecdysis. When insects eat the plants with these chemicals they may prematurely molt, lose weight, or suffer other metabolic damage and die. Chemically,…

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  • Halloween Genes Wiki

    Halloween Genes Wiki

    The halloween genes are a set of genes identified in Drosophila melanogaster that influence embryonic development. All of the genes code for cytochrome P450 enzymes in the ecdysteroidogenic pathway (biosynthesis of ecdysone from cholesterol). Ecdysteroids such as 20-hydroxyecdysone and ecdysone influence many of the morphological, physiological, biochemical changes that occur during molting in insects. Steroid hormones control many aspects of reproduction, development, and homeostasis in higher organisms.  In arthropods, steroid hormones play equal or even more…

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  • Chrysolina Beetles Have Cardiac Glycosides (Including Xylose) in Their Defensive Glands

    Chrysolina Beetles Have Cardiac Glycosides (Including Xylose) in Their Defensive Glands

    The defensive secretions of some chrysomelid beetles belonging to the genera Chrysolina, Chrysochloa, and Dlochrysa contain complex mixtures of cardenolides. The spectral data for some of these compounds suggest that they are monohydroxylated digitoxigenin derivatives linked to a pentose (such as xylose or arabinose). Evidence indicates that the beetles do not sequester these steroid glycosides…

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