Actomyosin contractility regulators stabilize the cytoplasmic bridge between the two primordial germ cells during Caenorhabditis elegans embryogenesis.

ABSTRACT: Stable cytoplasmic bridges arise from failed cytokinesis, the last step of cell division, and are a key feature of syncytial architectures in the germline of most metazoans. Whereas the Caenorhabditiselegans germline is syncytial, its formation remains poorly understood. We found that the germline precursor blastomere, P4 , fails cytokinesis, leaving a stable cytoplasmic bridge between the two daughter cells, Z2 and Z3 Depletion of several regulators of actomyosin contractility resulted in a regression of the membrane partition between Z2 and Z3, indicating that they are required to stabilize the cytoplasmic bridge. Epistatic analysis revealed a pathway in which Rho regulators promote accumulation of the noncannonical anillin ANI-2 at the stable cytoplasmic bridge, which in turns promotes the accumulation of the nonmuscle myosin II NMY-2 and the midbody component CYK-7 at the bridge, in part by limiting the accumulation of canonical anillin ANI-1. Our results uncover key steps in C. elegans germline formation and define a set of conserved regulators that are enriched at the primordial germ cell cytoplasmic bridge to ensure its stability during embryonic development.

SUBMITTER: Goupil E 

PROVIDER: S-EPMC5739295 | biostudies-literature | 2017 Dec

REPOSITORIES: biostudies-literature