title: Bayesian Inference of Forces Causing Cytoplasmic Streaming in Caenorhabditis elegans Embryos and Mouse Oocytes.
abstract: 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.
authors.affiliation: Department of Genetics, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Mishima, Japan.|Cell Architecture Laboratory, Structural Biology Center, National Institute of Genetics, Mishima, Japan.|Transdisciplinary Research Integration Center, Research Organization of Information and Systems, Tokyo, Japan.
authors.forename: Ritsuya
authors.initials: R
authors.lastname: Niwayama
authors.affiliation: Transdisciplinary Research Integration Center, Research Organization of Information and Systems, Tokyo, Japan.|Research and Development Center for Data Assimilation, The Institute of Statistical Mathematics, Tachikawa, Japan.
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Nagao
authors.affiliation: Laboratory for Chromosome Segregation, RIKEN Center for Developmental Biology (CDB), Kobe, Japan.
authors.forename: Tomoya S
authors.initials: TS
authors.lastname: Kitajima
authors.affiliation: Cell Biology and Biophysics Unit, EMBL Heidelberg, Heidelberg, Germany.
authors.forename: Lars
authors.initials: L
authors.lastname: Hufnagel
authors.affiliation: Developmental Genetics Group, Graduate School of Frontier Biosciences, Osaka University, Suita, Osaka, Japan.
authors.forename: Kyosuke
authors.initials: K
authors.lastname: Shinohara
authors.affiliation: Transdisciplinary Research Integration Center, Research Organization of Information and Systems, Tokyo, Japan.|Research and Development Center for Data Assimilation, The Institute of Statistical Mathematics, Tachikawa, Japan.
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Higuchi
authors.affiliation: Biological Flow Studies Laboratory, Department of Bioengineering and Robotics, Tohoku University, Sendai, Japan.
authors.forename: Takuji
authors.initials: T
authors.lastname: Ishikawa
authors.affiliation: Department of Genetics, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Mishima, Japan.|Cell Architecture Laboratory, Structural Biology Center, National Institute of Genetics, Mishima, Japan.|Transdisciplinary Research Integration Center, Research Organization of Information and Systems, Tokyo, Japan.
authors.forename: Akatsuki
authors.identifier: http://orcid.org/0000-0003-4227-4811
authors.initials: A
authors.lastname: Kimura
mesh_terms: D000818:Animals; D001499:Bayes Theorem; D017173:Caenorhabditis elegans / Q000196:embryology*; D003595:Cytoplasmic Streaming; D057446:Hydrodynamics; D016013:Likelihood Functions; D051379:Mice; D008954:Models, Biological; D009865:Oocytes / Q000378:metabolism*; D013314:Stress, Mechanical