Mechanisms of daughter cell-size control during cell division

•Dynein-dependent cortical pulling forces act on astral microtubules and control spindle position within the cell.•Myosin-dependent contractile forces control spindle position by altering cellular boundaries during anaphase.•Intrinsic signals induce cortical dynein and myosin asymmetry to rectify spindle mispositioning and produce equal-sized daughter cells.•Polarity signals produce cortical dynein and myosin asymmetry to displace the spindle, thus generating unequal-sized daughter cells.

Daughter cell size is tightly regulated during cell division. In animal cells, the position of the anaphase spindle specifies the cell cleavage site to dictate the relative size of the daughter cells. Although spindle orientation is regulated by dynein-dependent cortical pulling forces exerted on astral microtubules in many cell types, it was unclear how these forces are precisely regulated to center or displace the spindle. Recently, intrinsic signals derived from chromosomes or spindle poles have been demonstrated to regulate dynein-dependent pulling forces in symmetrically dividing cells. Unexpectedly, myosin-dependent contractile forces have also been shown to control spindle position by altering the cellular boundaries during anaphase. In this review, I discuss how dynein- and myosin-dependent forces are coordinately regulated to control daughter cell size.