  During asymmetric cell division, dynein generates forces, which position the
spindle to reflect polarity and ensure correct daughter cell fates. The
transient cortical localization of dynein raises the question of its targeting.
We found that it accumulates at the microtubule plus-ends like in budding
yeast, indirectly hitch-hiking on $\text{EBP-2}^{\text{EB1}}$ likely via
dynactin. Importantly, this mechanism, which modestly accounts for cortical
forces, does not transport dynein, which displays the same binding/unbinding
dynamics as $\text{EBP-2}^{\text{EB1}}$. At the cortex, dynein tracks can be
classified as having either directed or diffusive-like motion. Diffusive-like
tracks reveal force-generating dyneins. Their densities are higher on the
posterior tip of the embryos, where $\text{GPR-1/2}^{\text{LGN}}$ concentrate,
but their durations are symmetric. Since dynein flows to the cortex are
non-polarized, we suggest that this posterior enrichment increases dynein
binding, thus accounts for the force imbalance reflecting polarity, and
supplements the regulation of mitotic progression via the non-polarized
detachment rate.
