CSM News Electronic Edition Volume 2, number 13 April 9, 1994 Please submit abstracts of your papers as soon as they have been accepted for publication by sending them to CSM-News@worms.cmsbio.nwu.edu. Back issues of CSM-News, the CSM Reference database and other useful information is available by anonymous ftp from worms.cmsbio.nwu.edu [129.105.233.50], via Gopher at the same address, or by World Wide Web through www.nwu.edu. ---------- Abstracts ---------- Tomoaki Abe*, Florian Siegert+, Cornelis Weijer+ and Jeffrey Williams* *ICRF Clare Hall, S. Mimms, Herts EN6 3LD UK, +Zooloogisches Institut, Ludwig-Maximilians-Universitat, LuisenstraBe 14, 80333, Munchen, GERMANY Patterns of cell movement within the Dictyostelium slug revealed by cell type specific, surface labelling of living cells Cell, in press Summary There are cells scattered in the rear, prespore region of the Dictyostelium slug that share many of the properties of the prestalk cells and which are therefore called anterior-like cells (ALC). By placing the gene encoding a cell surface protein under the control of an ALC-specific promoter, and immunologically labelling the living cells, we analyse the movement of ALC within the slug. There is a posterior to anterior cellular flow and the ALC change their movement pattern as they enter the prestalk zone. Prestalk cells are periodically shed from the migrating slug. They must be replaced, if the correct ratio of prestalk to prespore cells is to be maintained, and we present evidence for the trans-differentiation of prespore into prestalk cells with ALC functioning as intermediates in the transition. The slug has, therefore, a surprisingly dynamic structure, both with respect to cellular differentiation and cell movement. -------------------------------------------------------------------- [End CSM-News, volume 2, number 13]