Within yeast colonial population, coordinated behaviour of individual cells in favour of the whole population is required and mediated by various signals. One such a signal is volatile ammonia.
New data provided hints on the function of the first pulse of ammonia production, which occurs early after colony inoculation (6-24 hrs). Detailed analysis of microcolonies of Sigma1278 derived strains revealed that early after new microcolony is originated from one cell, ammonia induces dimorphic transition resulting in oriented pseudohyphal cell expansion in the direction of ammonia source.
This consequently leads to unification of adjacent microcolonies to one more numerous entity and to subsequent development of unified microcolonies as one community.