Influence of electrochemical asymmetries on polarity.

<p>(A) During normal cell polarization, electrochemical layers segregate to the front and the back of the cell and may influence polarization processes, for instance during mating. (B) In an EF, the anode-facing side has hyperpolarized membrane potential, which drives anodal growth of the shmoos, in a Trk1-, Cho1<i>-</i>, and Far1-dependent manner. The secondary default orientation mode appears to be the cathodal orientation, which drives bud emergence and shmoo growth in <i>trk1</i>Δ, <i>cho1</i>Δ, and <i>far1-s</i> mutants by a yet unknown mechanism. (C) Optogenetic experiments directly suggest that local hyperpolarization of cell membrane potential can drive shmoo polarized growth but not bud site emergence. αF, α-factor.