Control of cell polarity by internal programs and external signals in yeast

Asymmetrical cellular organization, cell polarity, is fundamental to the development of multicellular organisms from egg to adult. Budding yeast (Saccharomyces cerevisiae) provides the opportunity to study the mechanisms responsible for producing an axis of polarity in a spatially regulated manner. In yeast, a number of genes are known which specifically affect either the orientation or the assembly of a polarity axis. Just as for other basic cellular functions, the mechanisms controlling cell polarity in yeast likely will be shared by multicellular organisms.