Effect of culture medium on the in vitro secretion activity of prothoracicglands from Pseudaletia separata

The prothoracic glands (PGs) taken from the last instar of the common armyw orm, Pseudaletia separata, were cultured in various media for the purpose o f finding a suitable medium for relatively long-term culture of PGs. Among the tested culture media, MGM-450 medium without serum was the best to main tain PG cells viable for relatively long periods, and to continue to secret e ecdysteroids. Secretion of ecdysteroid by the PG in vitro became marked w hen the PG; was taken from last instar larvae older than 2 days after the l ast molt. PGs cultured in any of the media secreted ecdysteroid only within the first 2 h after placing them in culture, however, in the MGM-450 mediu m, the PGs secreted ecdysteroid even after 5 days of culture. (C) 1998 Wile y-Liss, Inc.