title: Ecdysteroids during embryonation of eggs of Ascaris suum.
abstract: 1. The optimal temperature for in vitro development of fertilized eggs of Ascaris suum was 24 degrees C. 2. Samples (2 X 10(7) eggs) were obtained from in vitro embryonating cultures every 3 days for 4 weeks; lipids were extracted, partially purified, fractionated with HPLC and analyzed for ecdysteroids by radioimmunoassay. 3. Free ecdysone and 20-hydroxyecdysone (20-HE) were at low levels (less than 20 pg) in freshly excised eggs and rose to maximal values on day 6 of embryonation. 4. Conjugated ecdysone and conjugated 20-HE rose to maximal values on day 9. 5. Both free and conjugated ecdysteroids were undetectable from days 15 to 27 of cultivation. 6. These profiles indicate that ecdysteroids might have a selective role in nematode embryonation and/or tanning of the egg shell.
mesh_terms: D000818:Animals; D001200:Ascaris / Q000032:analysis / Q000196:embryology / Q000502:physiology*; D004440:Ecdysone / Q000032:analysis*; D004441:Ecdysterone / Q000032:analysis*; D005260:Female; D010063:Ovum / Q000502:physiology; D013696:Temperature
chemical_list: D004440:Ecdysone; D004441:Ecdysterone