Evidence that Y-organs of the crab Cancer antennarius secrete 3-dehydroecdysone.
Y-organs are paired glands in crustaceans that secrete a class of steroid hormones (ecdysteroids) that regulate growth, molting and development. The glandular secretion has been assumed to be solely the ecdysteroid, ecdysone, a polyhydroxylated derivative of cholesterol. We previously reported that Y-organs of a crab (Cancer antennarius) additionally secreted an ecdysteroid that is less polar than ecdysone. Evidence is presented here that the other secretion product is 3-dehydroecdysone (3-dhE). The compound co-chromatographed with authentic 3-dhE in both normal-phase, and reversed-phase, high-performance liquid chromatography. Mass spectrometry of the ecdysteroid gave results consistent with its identity as 3-dhE. The putative 3-dhE was radiolabeled by injecting crabs with [3H]cholesterol and then incubating the Y-organs. The putative [3H]3-dhE secretion was then subjected to chemical reduction. The reaction yielded labeled products that co-chromatographed with authentic ecdysone and 3-epiecdysone. Results of other experiments gave the following results: (1) Putative 3-dhE was not altered (chromatographic criteria) by incubations with snail hydrolases. (2) Putative [3H]3-dhE, added to incubations of Y-organ halves or homogenates, was not significantly converted to ecdysone; also, no conversion was evident after incubation in medium alone in which the hemolymph serum supplement was raised to 50% of the volume. (3) [3H]Ecdysone was not converted to putative 3-dhE in vitro by Y-organ halves or homogenates.(ABSTRACT TRUNCATED AT 250 WORDS)
Spaziani
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Department of Biology, University of Iowa, Iowa City 52242.
Rees
H H
HH
Wang
W L
WL
Watson
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RD
D000818:Animals; D003386:Brachyura / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D004440:Ecdysone / Q000031:analogs & derivatives* / Q000302:isolation & purification / Q000378:metabolism; D005260:Female; D006867:Hydrolases / Q000378:metabolism; D013058:Mass Spectrometry; D009924:Organ Culture Techniques
D004440:Ecdysone; C047104:3-dehydroecdysone; D006867:Hydrolases