Browsing by Author "Jacobs, Katherine C"

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    Chemotropism and Cell-Cell Fusion in Fungi.
    (Microbiology and molecular biology reviews : MMBR, 2022-02-09) Clark-Cotton, Manuella R; Jacobs, Katherine C; Lew, Daniel J
    Fungi exhibit an enormous variety of morphologies, including yeast colonies, hyphal mycelia, and elaborate fruiting bodies. This diversity arises through a combination of polar growth, cell division, and cell fusion. Because fungal cells are nonmotile and surrounded by a protective cell wall that is essential for cell integrity, potential fusion partners must grow toward each other until they touch and then degrade the intervening cell walls without impacting cell integrity. Here, we review recent progress on understanding how fungi overcome these challenges. Extracellular chemoattractants, including small peptide pheromones, mediate communication between potential fusion partners, promoting the local activation of core cell polarity regulators to orient polar growth and cell wall degradation. However, in crowded environments, pheromone gradients can be complex and potentially confusing, raising the question of how cells can effectively find their partners. Recent findings suggest that the cell polarity circuit exhibits searching behavior that can respond to pheromone cues through a remarkably flexible and effective strategy called exploratory polarization.
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    Mating in wild yeast: delayed interest in sex after spore germination.
    (Molecular biology of the cell, 2018-12) McClure, Allison W; Jacobs, Katherine C; Zyla, Trevin R; Lew, Daniel J
    Studies of laboratory strains of Saccharomyces cerevisiae have uncovered signaling pathways involved in mating, including information-processing strategies to optimize decisions to mate or to bud. However, lab strains are heterothallic (unable to self-mate), while wild yeast are homothallic. And while mating of lab strains is studied using cycling haploid cells, mating of wild yeast is thought to involve germinating spores. Thus, it was unclear whether lab strategies would be appropriate in the wild. Here, we have investigated the behavior of several yeast strains derived from wild isolates. Following germination, these strains displayed large differences in their propensity to mate or to enter the cell cycle. The variable interest in sex following germination was correlated with differences in pheromone production, which were due to both cis- and trans-acting factors. Our findings suggest that yeast spores germinating in the wild may often enter the cell cycle and form microcolonies before engaging in mating.