Microtubules provide directional information for core PCP function.
Bottom Line: Consistent with previous results, we find that the Ft/Ds/Fj-module has an effect on a MT-cytoskeleton.We show Ft/Ds/Fj-dependent initial polarization of the apical MT-cytoskeleton prior to global alignment of the core-module, reveal that the anchoring of apical non-centrosomal MTs at apical junctions is polarized, observe that directional trafficking of vesicles containing Dsh depends on Ft, and demonstrate the feasibility of this model by mathematical simulation.Together, these results support the hypothesis that Ft/Ds/Fj provides a signal to orient core PCP function via MT polarization.
Affiliation: Department of Pathology, Stanford University School of Medicine, Stanford, United States email@example.com.Show MeSH
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Mentions: Our results thus far suggest that gradients of Ds and Fj expression, by producing asymmetric orientation of Ft-Ds heterodimers, provide directional information to bias core protein polarization. Given the apparent variation in asymmetry of Ft-Ds dimers at different times and places in wing development, we wished to assess the potential consequences of this variation on core PCP protein asymmetry. We therefore simulated this mechanism by adapting our previously described mathematical model for PCP signaling (Amonlirdviman et al., 2005; Ma et al., 2008). The modified model establishes a MT network with polarity determined by the relative concentrations of Ft on any side of a cell. User-defined input gradients of Ds and Fj determine Ft concentrations in a manner consistent with the experimentally defined model. Dsh is then transported toward the plus ends of MTs, while still permitting bulk movement of all components by diffusion (see Supplementary file 1). We first validated the model by correctly reproducing the domineering non-autonomy (or lack thereof) surrounding clones of core PCP mutants (Figure 5—figure supplement 1). Furthermore, we confirmed that the model correctly simulates the ability of the core module to propagate polarization across small ft mutant clones (Figure 5—figure supplement 1).
Affiliation: Department of Pathology, Stanford University School of Medicine, Stanford, United States firstname.lastname@example.org.