Ecdysis in a parasitic nematode: direct evidence for an ecdysial factor from the head

Abstract

Incubating intact Phocanema decipiens in 0.9% NaCl containing insect juvenile hormone 1 (JH) leads to an increase in water volume of the excretory cell as determined by exchange with 3H2O, while incubation in 0.9% NaCl without JH does not. Ligaturing the head end of the worm prevents this increase and injection of extracts of heads into worms stimulates an increase in water content. Application of extract of heads to excretory cells in vitro also leads to an increase in water content of the cells.