Journal Article

Bayesian Inference of Forces Causing Cytoplasmic Streaming in Caenorhabditis elegans Embryos and Mouse Oocytes

Ishikawa, Takuji, Nagao, Hiromichi, Hufnagel, Lars, Kimura, Akatsuki, Kitajima, Tomoya S., Higuchi, Tomoyuki, Niwayama, Ritsuya, Shinohara, Kyosuke

2016

Overview

Cellular structures are hydrodynamically interconnected, such that force generation in one location can move distal structures. One example of this phenomenon is cytoplasmic streaming, whereby active forces at the cell cortex induce streaming of the entire cytoplasm. However, it is not known how the spatial distribution and magnitude of these forces move distant objects within the cell. To address this issue, we developed a computational method that used cytoplasm hydrodynamics to infer the spatial distribution of shear stress at the cell cortex induced by active force generators from experimentally obtained flow field of cytoplasmic streaming. By applying this method, we determined the shear-stress distribution that quantitatively reproduces in vivo flow fields in Caenorhabditis elegans embryos and mouse oocytes during meiosis II. Shear stress in mouse oocytes were predicted to localize to a narrower cortical region than that with a high cortical flow velocity and corresponded with the localization of the cortical actin cap. The predicted patterns of pressure gradient in both species were consistent with species-specific cytoplasmic streaming functions. The shear-stress distribution inferred by our method can contribute to the characterization of active force generation driving biological streaming.

• Publisher: Public Library of Science,Public Library of Science (PLoS)
• Subject: Actin / Animals / Bayes Theorem / Bayesian analysis / Biology and Life Sciences / Caenorhabditis elegans / Caenorhabditis elegans - embryology / Cellular structure / Computational fluid dynamics / Computer applications / Computer simulation / Cortex / Cytoplasm / Cytoplasmic Streaming / Developmental biology / Earthquakes / Embryonic development / Embryos / Flow velocity / Fluid flow / Generators / Genetic aspects / Hydrodynamics / In vivo methods and tests / Laboratories / Life sciences / Likelihood Functions / Localization / Meiosis / Mice / Models, Biological / Nematodes / Object motion / Oocytes / Oocytes - metabolism / Physical Sciences / Physiological aspects / R&D / Research & development / Research and Analysis Methods / Reynolds number / Shear stress / Spatial distribution / Statistical inference / Stress analysis / Stress concentration / Stress distribution / Stress, Mechanical / Studies