Time: 10:00 hrs

Location: Leiden, HL-214

abstract

How cells in developing organisms organize themselves into complex structures remains poorly understood. The vulva of the nematode worm /C. elegans/ is often used as a simple model system to study organ development. The C. elegans vulva develops from three cells to give rise to 22 vulva cells of 6 different cell types. In order to establish the correct spatial pattern of cell types, the developing vulva has to correctly interpret global signals, specifying the position and symmetry axis of the vulva, as well as local lateral signals between neighbouring cells, specifying cell fates. We study vulva development using a novel In Situ Hybridization technique that allows us to quantify gene expression on the level of single mRNAs as well as by timelapse microscopy of fluorescently labelled worms. These techniques allow us to study vulva development with an unprecedented level of quantitative detail, uncovering rich dynamics and considerable stochastic variation. Our findings directly contradict the established model for early vulva development and suggest a much more elaborate role for lateral signalling and asymmetrical cell divisions in the spatial patterning of the vulva than has been appreciated.