Model Systems: Yeast Cell Differentiation

Over the past year, the Galitski group has focused on the following:

Genetic Interactions
This year a computational study validating the maximal extraction of functional information from large-scale genetic-interaction networks was published. This approach has since been applied in studies of complex phenotype determination in yeast with combinatorial heterogeneous perturbations. PMCID: PMC2659753 . A free article.

Signaling Dynamics and Kinetic Genetics (with the Microfluidics and Imaging Core, and the Computational Biology Research group) This year a collaborative study of a panel of signaling mutants in microfluidics-enabled dynamic assays of signaling phenotypes was published. The study demonstrates that the combination of parallel microfluidic control with high-throughput imaging provides a powerful tool for systems-level studies of single-cell decision making. PMCID: PMC2644260 . A free article.

Yeast Thigmotropism
The Galitski group has completed a project investigating the nature of the inducer of yeast filamentation. Low availability of nutrients is thought to be the signal that induces this life-cycle transition. In contrast, it was found that filamentation is a thigmotropic response. These results suggest that yeast filamentation is primarily a response to surface contact for the purposes of stable surface colonization and efficient barrier penetration, rather than growing toward nutrients.

Proteomics of the FLO11 Promoter
To understand how gene expression is regulated, the dynamic composition of the complexes that assemble at gene regulatory elements must be comprehensively determined. To test our prediction that MOT3 is a repressor of FLO11, a new mass spectrometry based approach that identifies potential gene specific transcriptional regulatory proteins has been developed.