The Secretion of alpha-Ecdysone by the Prothoracic Glands of Manduca sexta In Vitro.
Prothoracic glands of tobacco hornworm larvae cultured in vitro secrete into the culture medium a substance which was active in ecdysone bioassays and determined to be ecdysone-like by radioimmunoassay. The prothoracic glands appear to be the sole source of this substance. The material was identified as alpha-ecdysone by thin-layer, gas-liquid, and high-resolution liquid chromatography and mass spectrometry. No other active moulting principles were present in the medium. It appears that the prothoracic gland secretes a prohormone, alpha-ecdysone, which is subsequently converted into the active moulting hormone, beta-ecdysone, in other insect tissues.
Biochemistry Department, Zoëcon Corporation, Palo Alto, California 94304.
D S
DS
King
W E
WE
Bollenbacher
D W
DW
Borst
W V
WV
Vedeckis
J D
JD
O'connor
P I
PI
Ittycheriah
L I
LI
Gilbert