RT Journal Article SR Electronic T1 Amphibian mucus triggers a developmental transition in the frog-killing chytrid fungus JF bioRxiv FD Cold Spring Harbor Laboratory SP 2022.01.21.477224 DO 10.1101/2022.01.21.477224 A1 Kristyn A Robinson A1 Sarah M Prostak A1 Evan H Campbell Grant A1 Lillian K Fritz-Laylin YR 2022 UL http://biorxiv.org/content/early/2022/01/23/2022.01.21.477224.abstract AB The frog-killing fungus Batrachochytrium dendrobatidis (Bd) grows within the mucus-coated skin of amphibians. Each lifecycle, Bd transitions from its motile, dispersal form to its sessile growth form in a complex process called encystation. Although encystation is critical to Bd growth, whether and how this developmental transition is triggered by external signals was previously unknown. We discovered that exposure to amphibian mucus triggers rapid and reproducible encystation within minutes. This response can be recapitulated with purified mucin, the bulk component of mucus, but not by similarly-viscous methylcellulose or simple sugars. Mucin-induced encystation does not require gene expression, but does require surface adhesion, calcium signaling, and modulation of the actin cytoskeleton. Mucus-induced encystation may represent a key mechanism for synchronizing Bd development with arrival at the host.Competing Interest StatementThe authors have declared no competing interest.