Rotation of stress fibers as a single wheel in migrating fish keratocytes

Abstract

Crawling migration plays an essential role in a variety of biological phenomena, including development, wound healing, and immune system function. Keratocytes are wound-healing cells in fish skin. Expansion of the leading edge of keratocytes and retraction of the rear are respectively induced by actin polymerization and contraction of stress fibers in the same way as for other cell types. Interestingly, stress fibers in keratocytes align almost perpendicular to the migration-direction. It seems that in order to efficiently retract the rear, it is better that the stress fibers align parallel to it. From the unique alignment of stress fibers in keratocytes, we speculated that the stress fibers may play a role for migration other than the retraction. Here, we reveal that the stress fibers are stereoscopically arranged so as to surround the cytoplasm in the cell body; we directly show, in sequential three-dimensional recordings, their rolling motion during migration. Removal of the stress fibers decreased migration velocity and induced the collapse of the left-right balance of crawling migration. The rotation of these stress fibers plays the role of a “wheel” in crawling migration of keratocytes.

Discovery of an F-actin–binding small molecule serving as a fluorescent probe and a scaffold for functional probes

“…In addition, as found for primary cultured cells and tissues, HMRef clearly visualized retrograde actin flow in migrating fish keratocytes (fig. S6 and movie S1) ( 15 , 16 ), as well as the contractile ring dynamics of cleavage furrow ingression during cell division in Drosophila wing disc ( Fig. 3, H and I ).…”

“…Keratocytes of Central American cichlids ( Hypsophrys nicaraguensis ) were cultured in culture medium (Leibovitz’s medium, L-15, L5520, Sigma-Aldrich, St Louis, MO) supplemented with 10% FBS (Nichirei, Tokyo, Japan) and antibiotic/antimycotic solution (09366-44, Nacalai Tesque, Kyoto, Japan) as previously described ( 16 ). All methods were carried out in accordance with national guidelines and the Regulation on Animal Experimentation at Yamaguchi University.…”

Comparative mapping of crawling-cell morphodynamics in deep learning-based feature space

“…Keratocytes from the scales of Central American cichlids ( Hypsophrys nicaraguensis ) were cultured as previously described [ 68 ] and images were recorded at 2-s intervals (N = 1590 snapshots from 12 timeseries;). Naïve CD4 + T cells were isolated from the lymph nodes and spleen of C57BL/6 mice by MidiMACS (Miltenyi Biotec).…”

Innate Immunity

“…They are also motile. The motility of fish keratocytes is studied in a number of fish species (Asbakk and Dalmo 1998;Tsuchida and Theriot 2013;Galbraith and Sheetz 1998;Jurado et al 2005;Okimura et al 2018;Ream et al 2003).…”