Conversion of 3-dehydroecdysone by a ketoreductase in post-diapause, pre-hatch eggs of the gypsy moth Lymantria dispar.
The prothoracic glands (PGs) of Lymantria dispar (day-5 female, last-stage larvae) produce both ecdysone and an ecdysteroid which has the same retention time on reverse-phase liquid chromatography (RPLC) as a known standard of 3-dehydroecdysone. The latter ecdysteroid can be converted by a heat-labile factor in extracts of post-diapause, pre-hatch L. dispar eggs to an ecdysteroid which has the same retention time on RPLC as ecdysone. Purified 3-dehydroecdysone, similarly treated with egg extract, also gives the same retention time on RPLC as ecdysone. Taken together, these data suggest that, like Manduca sexta, a major product of the PGs in L. dispar is 3-dehydroecdysone. Furthermore, these data suggest that L. dispar eggs, which contain mature embryos, possess ecdysteroid ketoreductase activity capable of converting 3-dehydroecdysone to ecdysone. This is the first report of ecdysteroid ketoreductase activity in embryonated eggs.
Kelly
T J
TJ
Insect Reproduction Laboratory, USDA, Beltsville, MD 20705.
Thyagaraja
B S
BS
Bell
R A
RA
Masler
E P
EP
Gelman
D B
DB
Borkovec
A B
AB
D015096:3-Hydroxysteroid Dehydrogenases / Q000378:metabolism*; D000818:Animals; D002853:Chromatography, Liquid; D004440:Ecdysone / Q000031:analogs & derivatives* / Q000378:metabolism; D005260:Female; D009036:Moths / Q000201:enzymology* / Q000502:physiology; D010063:Ovum / Q000201:enzymology; D011863:Radioimmunoassay
D004440:Ecdysone; C047104:3-dehydroecdysone; D015096:3-Hydroxysteroid Dehydrogenases; C020096:ecdysone oxidase