Worm Breeder's Gazette 16(1): 36 (October 1, 1999)

These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.

Vulva formation in Pristionchus pacificus relies on continuous gonadal induction.

Carola B. Sigrist, Ralf J. Sommer

Max-Planck Institut für Entwicklungsbiologie, Abt. Evolutionsbiologie, Spemannstrasse 35/IV, 72076 Tübingen, Germany

One of the best known features of vulva development in Caenorhabditis elegans is the induction of the vulval precursor cells by the gonadal anchor cell. Induction is crucial for the initiation of pattern formation within the C. elegans vulva equivalence group and therefore, it is surprising to find that this aspect of vulva formation in particular, varies greatly among nematodes. In some species which form vulvae in the posterior body region, no gonadal signal is necessary for vulva induction. In other nematodes, like Panagrolaimus, Oscheius and Rhabditella, vulva formation depends on two temporally distinct gonadal inductions which specify the different cell fates.

Cell ablation studies in P. pacificus show that another mode of vulva induction exists. P. pacificus vulva formation depends on a continuous gonadal induction that starts several hours after hatching and continues until the birth of the anchor cell, some 20 hours later. Mutations defective in gonadal induction result in the absence of vulva differentiation suggesting that only one signaling system is involved in the gonadal-epidermal interaction. Together, this new mode adds further to the great variety of gonadal inductions among nematode species.