Secretion of ecdysteroid by sheaths of testes of the gypsy moth,Lymantria dispar, and its regulation by testis ecdysiotropin

✍ Scribed by Loeb, M. J. ;Brandt, E. P. ;Woods, C. W. ;Bell, R. A.

• Publisher: John Wiley and Sons
• Year: 1988
• Tongue: English
• Weight: 700 KB
• Volume: 248
• Category: Article
• ISSN: 0022-104X
• DOI: 10.1002/jez.1402480112

✦ Synopsis

Testes of the gypsy moth, Lymantria dispar, secrete ecdysteroid in vitro during the silk-spinning pharate pupa stage and in mid to late adult development during the pupal stage. Low titers (3-6 pg/pl) of exogenous 20-hydroxyecdysone are required to elicit endogenous ecdysteroid production. Testis ecdysiotropin (TE) was detected in acid methanolic extracts of brains of immobile pharate pupae and mid-development pupae. It was possible to activate early last-instar testes of both L. dispar and Heliothis uirescens to synthesize ecdysteroid by exposing them to TE prepared from pupae of either species. Although testes of L. dispar contained no detectable ecdysone, they were able to convert (3H) ecdysone to 20-hydroxyecdysone and a highly polar fraction. The active ecdysteroid product of L. dispar testes is probably 20-hydroxyecdysone. Testes of Mamestra brassicae (Shimizu et al., '85) and testis sheaths of Heliothis uirescens (Loeb et al., '82) spontaneously secrete 9-12 different immunologically detectable ecdysteroids in vitro. Secretion