Flo11p adhesin required for meiotic differentiation in Saccharomyces cerevisiae minicolonies grown on plastic surfaces


  • Editor: Ian Dawes

Correspondence: Saul M. Honigberg, Division of Cell Biology and Biophysics, School of Biological Sciences, University of Missouri-Kansas City, 5007 Rockhill Rd, Kansas City, MO 64110, USA. Tel.: +1 816 235 2578; fax: +1 816 235 6553; e-mail:


Saccharomyces cerevisiae grown on plastic surfaces formed organized structures, termed minicolonies, that consisted of a core of round (yeast-like) cells surrounded by chains of filamentous cells (pseudohyphae). Minicolonies had a much higher affinity for plastic than unstructured yeast communities growing on the same surface. Pseudohyphae at the surface of these colonies developed further into chains of asci. These structures suggest that pseudohyphal differentiation and sporulation are sequential processes in minicolonies. Consistent with this idea, minicolonies grown under conditions that stimulated pseudohyphal differentiation contained higher frequencies of asci. Furthermore, a flo11Δ mutant, which fails to form pseudohyphae, yielded normal sporulation in cultures, but was defective for minicolony sporulation. When minicolonies were dispersed in water and cells were then allowed to settle on the plastic surface, these cells sporulated very efficiently. Taken together, our results suggest that sporulation in minicolonies is stimulated by pseudohyphal differentiation because these pseudohyphae are dispersed from the core of the colony.