title: Variability and Constancy in Cellular Growth of Arabidopsis Sepals.
abstract: Growth of tissues is highly reproducible; yet, growth of individual cells in a tissue is highly variable, and neighboring cells can grow at different rates. We analyzed the growth of epidermal cell lineages in the Arabidopsis (Arabidopsis thaliana) sepal to determine how the growth curves of individual cell lineages relate to one another in a developing tissue. To identify underlying growth trends, we developed a continuous displacement field to predict spatially averaged growth rates. We showed that this displacement field accurately describes the growth of sepal cell lineages and reveals underlying trends within the variability of in vivo cellular growth. We found that the tissue, individual cell lineages, and cell walls all exhibit growth rates that are initially low, accelerate to a maximum, and decrease again. Accordingly, these growth curves can be represented by sigmoid functions. We examined the relationships among the cell lineage growth curves and surprisingly found that all lineages reach the same maximum growth rate relative to their size. However, the cell lineages are not synchronized; each cell lineage reaches this same maximum relative growth rate but at different times. The heterogeneity in observed growth results from shifting the same underlying sigmoid curve in time and scaling by size. Thus, despite the variability in growth observed in our study and others, individual cell lineages in the developing sepal follow similarly shaped growth curves.
authors.affiliation: Computational Science and Engineering Laboratory, ETH Zürich, 8092 Zurich, Switzerland (G.T., P.K.);Weill Institute for Cell and Molecular Biology (H.M.M., A.H.K.R.), Genetics, Genomics, and Development Program (H.M.M., A.H.K.R), and School of Integrative Plant Sciences, Section of Plant Biology (A.H.K.R), Cornell University, Ithaca, New York 14853; andDepartment of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany (R.S.S.).
authors.forename: Gerardo
authors.initials: G
authors.lastname: Tauriello
authors.affiliation: Computational Science and Engineering Laboratory, ETH Zürich, 8092 Zurich, Switzerland (G.T., P.K.);Weill Institute for Cell and Molecular Biology (H.M.M., A.H.K.R.), Genetics, Genomics, and Development Program (H.M.M., A.H.K.R), and School of Integrative Plant Sciences, Section of Plant Biology (A.H.K.R), Cornell University, Ithaca, New York 14853; andDepartment of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany (R.S.S.).
authors.forename: Heather M
authors.initials: HM
authors.lastname: Meyer
authors.affiliation: Computational Science and Engineering Laboratory, ETH Zürich, 8092 Zurich, Switzerland (G.T., P.K.);Weill Institute for Cell and Molecular Biology (H.M.M., A.H.K.R.), Genetics, Genomics, and Development Program (H.M.M., A.H.K.R), and School of Integrative Plant Sciences, Section of Plant Biology (A.H.K.R), Cornell University, Ithaca, New York 14853; andDepartment of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany (R.S.S.).
authors.forename: Richard S
authors.initials: RS
authors.lastname: Smith
authors.affiliation: Computational Science and Engineering Laboratory, ETH Zürich, 8092 Zurich, Switzerland (G.T., P.K.);Weill Institute for Cell and Molecular Biology (H.M.M., A.H.K.R.), Genetics, Genomics, and Development Program (H.M.M., A.H.K.R), and School of Integrative Plant Sciences, Section of Plant Biology (A.H.K.R), Cornell University, Ithaca, New York 14853; andDepartment of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany (R.S.S.).
authors.forename: Petros
authors.identifier: http://orcid.org/0000-0001-8337-2122
authors.initials: P
authors.lastname: Koumoutsakos
authors.affiliation: Computational Science and Engineering Laboratory, ETH Zürich, 8092 Zurich, Switzerland (G.T., P.K.);Weill Institute for Cell and Molecular Biology (H.M.M., A.H.K.R.), Genetics, Genomics, and Development Program (H.M.M., A.H.K.R), and School of Integrative Plant Sciences, Section of Plant Biology (A.H.K.R), Cornell University, Ithaca, New York 14853; andDepartment of Comparative Development and Genetics, Max Planck Institute for Plant Breeding Research, 50829 Cologne, Germany (R.S.S.) ahr75@cornell.edu.
authors.forename: Adrienne H K
authors.identifier: http://orcid.org/0000-0001-6685-2984
authors.initials: AH
authors.lastname: Roeder
mesh_terms: D017360:Arabidopsis / Q000166:cytology / Q000235:genetics / Q000254:growth & development*; D002455:Cell Division; D019070:Cell Lineage; D002473:Cell Wall / Q000378:metabolism; D035264:Flowers / Q000166:cytology / Q000235:genetics / Q000254:growth & development*; D008954:Models, Biological; D019441:Plant Epidermis / Q000166:cytology / Q000235:genetics / Q000254:growth & development