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Module 1: Delta-Notch (ODE systems, ODEs on a grid)

Author: Fabian Rost

Aim

  • learn about ODE models (dynamics in morpheus, steady states analytically)
  • develop first models

Description

Basic ODEs

  • get to know what students know about ODEs and adjust the module to the pre-knowledge
  • give them very simple sketches of biomolecular models, which they should translate into ODEs, e.g.

  • could be translated to the following ODEs:

\begin{align} \dot A &= k_1 \\ \dot A &= k_2 A \\ \dot A &= - k_3 A \\ \dot A &= k_4 - k_5 A \end{align}

  • discuss those ODEs by
    • calculate steady state (do not calculate the stability, to complicated for biologists)
    • simulate in morpheus

Delta-Notch

  • then discuss the delta-notch sketch with two species
    • start with the Collier model
    • let them simplify the Collier model sketch (remove the delta or notch species)
    • let them develop an ODE for this system (they should be able to do so from the above examples)
    • they could come up with something like:

\begin{align} \dot X_1 &= c \frac{\theta^n}{\theta^n + X_2^n} - k X_1 \\ \dot X_2 &= c \frac{\theta^n}{\theta^n + X_1^n} - k X_2 \end{align}

  • this system is bistable for certain parameter ranges, if the students are advanced they might find this out themselves
  • bistable e.g. for $\theta=0.5$, $n=4$, $c=k=1$
  • if they have this system running in morpheus go spatial and let them simulate the system on a square and hexagonal grid
  • then you could also move to shaped cpm cells or even moving cells
  • students won't do so much on their own in this session, it is a lot teaching on ODEs (don't be theoretical here, not enough time!) and introducing morpheus

Paper:

  • Joanne R. Collier, Nicholas A.M. Monk, Philip K. Maini, Julian H. Lewis, Pattern Formation by Lateral Inhibition with Feedback: a Mathematical Model of Delta-Notch Intercellular Signalling, Journal of Theoretical Biology, Volume 183, Issue 4, 21 December 1996, Pages 429-446, ISSN 0022-5193, http://dx.doi.org/10.1006/jtbi.1996.0233.

Morpheus models

h ExponentialGrowth.xml |h

<?xml version='1.0' encoding='UTF-8'?>
<MorpheusModel version="1">
    <Description>
        <Title>Exponential Growth</Title>
    </Description>
    <Space>
        <Lattice class="linear">
            <Size value="0 0 0"/>
        </Lattice>
    </Space>
    <Time>
        <StartTime value="0"/>
        <StopTime value="100"/>
    </Time>
    <CellTypes>
        <CellType class="biological" name="cell">
            <System time-step="1.0">
                <DiffEqn symbol-ref="A">
                    <Expression>k*A</Expression>
                </DiffEqn>
            </System>
            <Property symbol="A" value="1.0"/>
            <Constant symbol="k" value="0.1"/>
        </CellType>
    </CellTypes>
    <CellPopulations>
        <Population size="1" type="cell"/>
    </CellPopulations>
    <Analysis>
        <Logger interval="1">
            <Format string="A"/>
            <Input>
                <Cell mapping="all" celltype="cell"/>
            </Input>
            <Plot interval="10" terminal="wxt" persist="true">
                <X-axis column="1"/>
                <Y-axis columns="3"/>
            </Plot>
        </Logger>
    </Analysis>
</MorpheusModel>

documentation/course/module1.1510573116.txt.gz · Last modified: 12:38 13.11.2017 by Fabian Rost

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