One of the most important problems in developmental biology is to determine the mechanisms responsible for morphogenesis. Morphogenesis happens mostly during embryonic development and involves regulated cell division of the fertilised egg to produce many cells that differentiate into a number of cell types. These are then arranged in a well ordered spatial pattern in a defined temporal sequence. The aim of this PhD thesis research programme is to understand the cellular basis of morphogenesis of a simple organism, the slime mould Dictyostelium discoideum. Based on previous experiments we have developed a working hypothesis to explain the control of cell movement during Dictyostelium morphogenesis.
Slime mould cells proliferate as unicellular amoebae, which feed on bacteria in the soil.
When food becomes limited, the amoebae enter an aggregation phase, leading to the formation of a multi cellular aggregate, the mound. In the mound cells differentiate into several cell types and the mound then transforms into a motile structure, the slug, with a clear polarity and an axial pattern formed by differentiated cells. The slug moves to a suitable place to produce a fruiting body, which consists of several stalk and spore cells. The spores disperse, germinate and the cycle can start over again. However the later stages of development slug formation and migration and culmination are less well understood both experimentally and theoretically.