EVIDENCE FOR THE SORTING OUT OF CELLS IN THE DEVELOPMENT OF THE CELLULAR SLIME MOLDS

Abstract

During the aggregation of cellular slime molds there is a redistribution of cells, and the more rapidly moving cells may assume an anterior position in the resulting slug, while the slower cells lie posteriorly. To test the possibility of cellular redistribution, 2 compatible cell types were mixed and, although their initial distribution must have been random, their eventual distribution in the slug was markedly non-random. It was found that if a slug were cut up into sections and each fraction allowed to fruit, the spores from anterior fractions were larger than those from posterior fractions. During aggregation, there is a sorting out of cells, and the faster-moving large cells are found in higher concentration at the front end of the slug while the smaller cells accumulate at the hind end.