RRC ID 57361
Author Zhang Y, Yu JC, Jiang T, Fernandez-Gonzalez R, Harris TJC.
Title Collision of Expanding Actin Caps with Actomyosin Borders for Cortical Bending and Mitotic Rounding in a Syncytium.
Journal Dev Cell
Abstract The early Drosophila embryo is a large syncytial cell that compartmentalizes mitotic spindles with furrows. Before furrow ingression, an Arp2/3 actin cap forms above each nucleus and is encircled by actomyosin. We investigated how these networks transform a flat cortex into a honeycomb-like compartmental array. The growing caps circularize and ingress upon meeting their actomyosin borders, which become the furrow base. Genetic perturbations indicate that the caps physically displace their borders and, reciprocally, that the borders resist and circularize their caps. These interactions create an actomyosin cortex arrayed with circular caps. The Rac-GEF Sponge, Rac-GTP, Arp3, and actin coat the caps as a growing material that can drive cortical bending for initial furrow ingression. Additionally, laser ablations indicate that actomyosin contraction squeezes the cytoplasm, producing counterforces that swell the caps. Thus, Arp2/3 caps form clearances of the actomyosin cortex and control buckling and swelling of these clearances for metaphase compartmentalization.
Volume 45(5)
Pages 551-564.e4
Published 2018-6-4
DOI 10.1016/j.devcel.2018.04.024
PII S1534-5807(18)30330-7
PMID 29804877
MeSH Actins / metabolism* Actomyosin / metabolism* Animals Cell Membrane Drosophila Proteins / genetics Drosophila Proteins / metabolism* Drosophila melanogaster / genetics Drosophila melanogaster / growth & development Drosophila melanogaster / metabolism* Embryo, Nonmammalian / cytology Embryo, Nonmammalian / metabolism* Giant Cells / cytology Giant Cells / physiology* Microtubules / metabolism Spindle Apparatus / physiology*
IF 9.19
Times Cited 7
Drosophila DGRC#115159