-Back-to-back mechanisms drive actomyosin ring closure during Drosophila embryo cleavage.

ABSTRACT: Contraction of actomyosin rings during cytokinesis is typically attributed to actin filaments sliding toward each other via Myosin-2 motor activity. However, rings constrict in some cells in the absence of Myosin-2 activity. Thus, ring closure uses Myosin-2-dependent and -independent mechanisms. But what the Myosin-2-independent mechanisms are, and to what extent they are sufficient to drive closure, remains unclear. During cleavage in Drosophila melanogaster embryos, actomyosin rings constrict in two sequential and mechanistically distinct phases. We show that these phases differ in constriction speed and are genetically and pharmacologically separable. Further, Myosin-2 activity is required for slow constriction in "phase 1" but is largely dispensable for fast constriction in "phase 2,"

SUBMITTER: Xue Z 

PROVIDER: S-EPMC5100295 | biostudies-literature | 2016 Nov

REPOSITORIES: biostudies-literature