title: Dicapryloylglycerol and ammonium ions induce metamorphosis of ascidian larvae.
abstract: Larvae of the tunicate Ciona start metamorphosis between some hours and a few days after hatching. Several substances were found to reduce this time span, such as vital dyes [Cloney (1961) Am Zool 1:67-87; Hirani (1961) Bull Mar Biol Stn Asamushi 11:121-125], heavy-metal ions including copper [see review by Lynch (1961) Am Zool 1:59-66] and the hormone thyroxine [Patricolo et al. (1981) Cell Tissue Res 214:289-301]. This study shows that low concentrations of ammonium ions as well as the second messenger dicapryloylglycerol induce metamorphosis immediately after hatching. On the other hand, when the follicle cells are removed newly hatched Ciona remain larvae for days. Follicle cells are possibly degraded by bacteria, which thereby produce ammonia.
authors.affiliation: Zoologisches Institut der Universität Köln, Weyertal 119, D-5000, Köln 41, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Berking
authors.affiliation: Zoologisches Institut der Universität Köln, Weyertal 119, D-5000, Köln 41, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Herrmann
keywords: Ammonium ions; Ascidia; Diacylglycerol; Metamorphosis