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. Author manuscript; available in PMC: 2018 May 22.
Published in final edited form as: Dev Cell. 2015 Oct 12;35(1):131–142. doi: 10.1016/j.devcel.2015.09.006

Figure 2. PAR-2 and LGL-1 prevent loss of PAR asymmetry during maintenance by patterning cortical flow.

Figure 2

(A) Dynamics of cortical myosin II (NMY-2::GFP) during maintenance phase in control (par-2(lw32) heterozygotes), par-2(lw32), and par-2(lw32);lgl-1(tm-2616) embryos. Top and bottom rows show surface views of cortical NMY-2::GFP at late PC and NEBD. Kymographs show patterns of cortical flow during maintenance phase. Dashed rectangle in top left of (A) indicates region from kymographs were constructed in (A), (D) and (E). Yellow and blue shading indicates posterior and anterior contraction phases respectively (see main text for details). Arrows indicate general direction and speed of cortical flow. (B) Cortical flow velocities during posterior (top) and anterior (bottom) contraction phases for wild type, par-2 and par-2;lgl-1 embryos. Dashed vertical line indicates approximate position of GFP:PAR-6 boundary (see F). Error bars indicate +/− 1 SEM for n = 10 embryos. (C) (top) Localization of a biosensor for active CDC-42 (GFP::wspGBD) at PC and NEBD in a wild-type embryo; (bottom) GFP::wspGBD fluorescence intensity vs. time for anterior (magenta) and posterior (blue) domains showing biphasic accumulation of the biosensor. Error bars indicate mean +/− 1 SEM for n = 12 embryos aligned to the onset of maintenance (t = 0). (D&E) Dynamics of cortical GFP::PAR-6 during maintenance phase in embryos of the indicated genotypes without (D), or with (E) mrck-1(RNAi). Surface views and kymographs are as in (A). (F) GFP::PAR-6 intensity vs. anterior/posterior position at the end of PC and NEBD in control (n = 10), par-2(lw32) (n = 11), par-2(lw32);lgl-1(tm2616) (n = 10), mrck(RNAi) (n = 10), par-2(lw32); mrck(RNAi) (n = 10), and par-2(lw32); lgl-1(tm2616); mrck(RNAi) (n = 10) embryos. Error bars indicate +/− 1 SEM. (G) Box and whisker plots showing the distributions of GFP::PAR-6 boundary position for the data in (F). ** p < 0.005 by Students T test. (H) GFP::PAR-6 intensity profiles measured for the same genotypes at 20 sec intervals during maintenance phase in single embryos. Heat map indicates time relative to the beginning of the anterior contraction phase. See also Figure S1 and Movies S1 & S2.