Document Detail


Entomogenous fungus Nomuraea rileyi inhibits host insect molting by C22-oxidizing inactivation of hemolymph ecdysteroids.
MedLine Citation:
PMID:  12489132     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The entomogenous fungus Nomuraea rileyi reportedly secretes a proteinaceous substance inhibiting larval molt and metamorphosis in the silkworm Bombyx mori. We studied the possibility that N. rileyi controls B. mori development by inactivating hemolymph molting hormone, ecdysteroids. Incubation of ecdysone (E) and 20-hydroxyecdysone (20E) in fungal-conditioned medium resulted in their rapid modification into products with longer retention times in reverse-phase HPLC. Each modified product from E and 20E was purified by HPLC, and identified by NMR as 22-dehydroecdysone and 22-dehydro-20-hydroxyecdysone. Some other ecdysteroids with a hydroxyl group at position C22 were also modified. Injection of the fungal-conditioned medium into Bombyx mori larvae in the mid-4th instar inhibited larval molt but induced precocious pupal metamorphosis, and its injection into 5th instar larvae just after gut purge blocked pupal metamorphosis. In hemolymph of injected larvae, E and 20E disappeared and, in turn, 22-dehydroecdysone and 22-dehydro-20-hydroxyecdysone accumulated. These results indicate that N. rileyi secretes a specific enzyme that oxidizes the hydroxyl group at position C22 of hemolymph ecdysteroids and prevents molting in B. mori larvae.
Authors:
Makoto Kiuchi; Hiroe Yasui; Shoji Hayasaka; Manabu Kamimura
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Archives of insect biochemistry and physiology     Volume:  52     ISSN:  0739-4462     ISO Abbreviation:  Arch. Insect Biochem. Physiol.     Publication Date:  2003 Jan 
Date Detail:
Created Date:  2002-12-18     Completed Date:  2003-03-03     Revised Date:  2007-11-15    
Medline Journal Info:
Nlm Unique ID:  8501752     Medline TA:  Arch Insect Biochem Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  35-44     Citation Subset:  IM    
Copyright Information:
Copyright 2003 Wiley-Liss, Inc.
Affiliation:
National Institute of Agrobiological Sciences, Tsukuba, Ibaraki, Japan.
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MeSH Terms
Descriptor/Qualifier:
Animals
Bombyx / growth & development*,  parasitology*
Chromatography, High Pressure Liquid / methods
Ecdysteroids / antagonists & inhibitors*,  metabolism,  pharmacology
Hemolymph / chemistry
Host-Parasite Interactions
Hydroxyl Radical / chemistry
Larva / drug effects,  growth & development
Mitosporic Fungi / classification,  metabolism,  physiology*
Molting
Nuclear Magnetic Resonance, Biomolecular
Oxidation-Reduction
Chemical
Reg. No./Substance:
0/Ecdysteroids; 3352-57-6/Hydroxyl Radical

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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