Quantification of variability in trichome patterns

Abstract

While pattern formation is studied in various areas of biology, little is known about the noise leading to variations between individual realizations of the pattern. One prominent example for de novo pattern formation in plants is the patterning of trichomes on Arabidopsis leaves, which involves genetic regulation and cell-to-cell communication. These processes are potentially variable due to, e.g., the abundance of cell components or environmental conditions. To elevate the understanding of regulatory processes underlying the pattern formation it is crucial to quantitatively analyze the variability in naturally occurring patterns. Here, we review recent approaches toward characterization of noise on trichome initiation. We present methods for the quantification of spatial patterns, which are the basis for data-driven mathematical modeling and enable the analysis of noise from different sources. Besides the insight gained on trichome formation, the examination of observed trichome patterns also shows that highly regulated biological processes can be substantially affected by variability.

A stochastic multicellular model identifies biological watermarks from disorders in self-organized patterns of phyllotaxis

“…While more demanding computationally, stochastic models are required in such cases, e.g . ( Greese et al, 2014 ; Uyttewaal et al, 2012 ; Wennekamp et al, 2013 ), and our work illustrates how dynamic stochastic modeling can help understanding quantitatively self-organization and more broadly patterning in higher eukaryotes.…”

Fluctuations of the transcription factor ATML1 generate the pattern of giant cells in the Arabidopsis sepal

“…These activators amplify both their own expression and the expression of faster-diffusing transcriptional repressors that move to the neighboring cell to create a non-random distribution of trichomes, following a Turing-like model ( Hülskamp, 2004 ; Meinhardt and Gierer, 1974 ; Turing, 1952 ). Several transcriptional regulators needed for trichome patterning have been identified that support this model ( Bouyer et al, 2008 ; Greese et al, 2014 ; Hülskamp and Schnittger, 1998 ; Hülskamp, 2004 ; Schellmann et al, 2002 ). However, the stochastic fluctuations of these genes remain to be observed in vivo during trichome development.…”

Themes and variations in cell type patterning in the plant epidermis

“…Many patterning mechanisms, including trichomes, are thought to be initiated by stochastic fluctuations in regulators; feedback loops, including the MBW complex and intercellular signaling networks, amplify and modify these differences to create the pattern [24,79,80]. Although there is no evidence for the involvement of an MBW complex, there is evidence that intercellular signaling is required for giant cell formation.…”