Menu

Close

Signaling dynamics control cell fate in the early Drosophila embryo

Heath E Johnson, Stanislav Y Shvartsman, Jared E Toettcher

Preprint posted on June 08, 2018 https://www.biorxiv.org/content/early/2018/06/08/342998

How can the same molecule specify different dev outcomes? By systematically inducing Erk signalling using optogenetics, a preprint by @toettch lab suggests that differences in the dynamics of signalling underlie different cell fates in fly embryos

Selected by Yara E. Sánchez Corrales

Background

The Erk mitogen-activated protein kinase is required for cells to adopt different fates during early embryogenesis in the fruit fly at least in three different contexts:

  • Anterior pole, where Erk is implied in the formation of head structures
  • Ventral midline, where Erk is involved in the patterning underlying neural precursors
  • Posterior pole, where Erk influences posterior midgut invagination

 How could the same signalling molecule specify different cell fates? An attractive hypothesis is called dynamic control which posits that a single signal can be interpreted differently depending on its dynamic features such as amplitude, duration or frequency of activation.

In order to explore whether Erk signalling in the developing embryo is decoded by dynamic control, the authors use a recent tool, the OptoSOS system, that permits the precise manipulation of Erk signalling using light. Upon blue light stimulation, a Ras activator goes to the membrane and this activates a kinase cascade that culminates in the activation of Erk signalling (see Johnson et al., 2017 for more details). Using this tool in combination with genetic manipulations, the authors are able to test different hypotheses related to the dynamic decoding of Erk signalling.

Key findings

The authors start by inducing Erk signalling in the whole embryo using homogeneous illumination. This perturbation induces tissue contractions that are explained by the ectopic expression of myosin II. Importantly, upon light stimulation the receptor-ligand pair mist and folded gastrulation (fog), involved in tissue contractility in the embryo, are also upregulated. In order to address which network is involved in ectopic contraction, the authors assess the expression pattern of some transcription factors known to promote contractility during development. They find that the light-induced Erk is able to expand the expression domain of tailess (tll) and huckebein (hkb), two transcription factors associated with posterior midgut (PMG) invagination. Thus, ectopic Erk signalling is sufficient to drive cells to adopt a contractile PMG-like fate.

Interestingly, the 85% posterior part of the embryo shows higher level of myosin activation compared to the anterior, suggesting that contractility mediated by Erk is suppressed in the anterior part of the embryo. The authors show that high levels of Bicoid (Bcd) block Erk-dependent contraction behaviour because when Bcd is removed (ie. bcd mutant), Erk induces uniform contractility. This suggests that the combination of signals, Bcd and Erk, underlies head structures in the anterior part of the embryo. Thus, it is an example of combinatorial control.

The authors next tested the effects of the time and duration of Erk signaling that is known to be different in normal development. For instance, in the PMG, Erk expresses early during the first nuclear cycles while in the ventral midline it expresses just before gastrulation during the 14th nuclear cycle. Moreover, in the PMG, Erk is sustained for over 1h while in the ventral midline is a transient 20 min pulse. Using the OptoSOS tool, the authors systematically vary the time and the duration of Erk signalling (i.e light induction for 30, 45, 60 or 120 min through different developmental times). They find that the duration of stimuli, regardless of the specific developmental window, predicts the response to Erk stimulation very well. Interestingly, short time stimulation (30 min) leads to increased levels of ind (associated with neuron specification) and longer stimulation (120 min) caused ectopic expression of mist, associated with contractility. Thus, the duration of Erk signalling is able to direct cell fate towards neuron precursors or contractile behaviour.

How is Erk signalling decoded within the cell? Two different models have been proposed: 1) persistence detector and 2) cumulative load sensor (Figure 1). In the former, persistent pulses of Erk stimuli are needed for downstream responses. In the second, distinct cell fates are triggered when the total signal reaches a threshold (Figure 1). These mechanisms can be distinguished by the phenotypic response to a pulsed versus a continuos stimulus. Erk induction divided into three equal pulses (3×5 or 3×15 min) leads to similar phenotypes to those observed in the case of single doses (15 or 45 min), suggesting that it is the total or cumulative Erk activity that is decoded.

Figure 1. The persistence detector and the cumulative load sensor are two mechanisms that could decode Erk signalling (a). In order to distinguish between them, Erk can be induced in pulses or as continuos stimulus. The cumulative sensor mechanism predicts the same response regardless of the shape of the stimuli (b). Induction of Erk signalling leads to similar phenotypic responses regardless of the shape of stimuli ( b), supporting the the cumulative load mechanism. (Figure 4 of the original preprint).

The authors also explore the type of genes that could be involved in decoding Erk signalling under the cumulative detector mechanism. They propose two different decoding types of genes: the accumulators and the thresholders. The accumulators will integrate the signal over time, thus their expression level will be proportional to the intensity of the stimuli. The thresholders will act as a switch and would increase abruptly above a stimulus threshold. The authors find that the terminal gap genes tll and hkb respond as predicted for accumulator genes, while hkb and mist act as a thresholders genes turning on abruptly after 30-45 min of stimulation.

Figure 2. Summary of Erk signalling dynamics implied in different cell fates during Drosophila embryo development (Figure 5 of the original preprint).

What I like about this preprint and open questions

 In this study, the use of an optogetic tool makes it possible to systematically control the spatial and temporal dynamics of Erk signalling. In my opinion, the combination of these kinds of quantitative tools and genetic perturbations make the Drosophila embryo a remarkable system for unravelling the dynamic features of both signalling and genetic networks.

I am convinced that quantitation and precise manipulation of dynamic signalling features (such as duration, intensity and time of stimuli) adds another level of understanding to signalling pathways by incorporating the temporal decoding of signalling.

I would like to know if the authors also tried to modulate the amounts of signalling levels by controlling the amplitude of the signal. If the cumulative load mechanism is driving the process, would a single high intensity stimulus produce the same effects as a prolonged low intensity stimuli?

I also wonder about the role of pulse frequency and periodicity. Could the frequency and period of activation be important? Presumably, other response genes could be influenced by a pulsatile behaviour.

I find it very interesting that induction of Erk increased contractility and induced myosin II ectopic expression. It is know that myosin II can be junctional or show pulses in the apico-medial domain. The former is associated with junction shrinking and the latter with decrease in cell area. I wonder if Erk overexpression will also change these distinct contractile behaviours.

I also really like the idea of unravelling the network behaviour that could decode signalling. I wonder whether “thresholders” and “accumulators” could also be part of a persistence decoding mechanism.

Finally, I find this preprint very inspiring and hope that approaches like this will help unravel more examples of dynamic control in development.

 

Tags: cell fate, contractility, myosin ii, optogenetics

Posted on: 18th October 2018 , updated on: 22nd October 2018

Read preprint (No Ratings Yet)




  • Author's response

    Jared Toettcher shared

    We are honored to be featured in preLights! We are also quite impressed
    with the depth and accuracy with which our paper was presented; for us,
    this discussion really underscores the value of publishing preprints.

    The open questions raised in the preLight are all excellent ones. First:
    your are correct that the “cumulative load” model predicts an
    equivalence between amplitude and duration. Put simply: if the total
    dose is all that the cell cares about, then a brief, bright pulse of
    light should give the same phenotype as a long, dim one. Indeed, this is
    one experimental direction we have pursued since publishing the preprint
    – and so far, the results appear to confirm our model. We hope to
    publish a revised manuscript soon!

    A second question revolves around the frequency of stimulation. This is
    something we are *very* interested in, especially as Erk activity has
    been shown to pulse (or oscillate) in many mammalian model systems. In
    mammalian cells, we have shown that repeated pulses of Erk can turn on
    some genes more efficiently than a single, constant stimulus (Wilson et
    al, Mol Cell 2017). Intriguingly, Erk pulses have not yet been observed
    in the fly – but I strongly suspect that they soon will…

    Have your say

    Your email address will not be published. Required fields are marked *

    Sign up to customise the site to your preferences and to receive alerts

    Register here

    Also in the cell biology category:

    Drosophila kinesin-8 stabilises kinetochore-microtubule interaction

    Tomoya Edzuka, Gohta Goshima



    Selected by Ben Craske, Thibault Legal and Toni McHugh

    1

    Unjamming overcomes kinetic and proliferation arrest in terminally differentiated cells and promotes collective motility of carcinoma.

    Andrea Palamidessi, Chiara Malinverno, Emanuela FRITTOLI, et al.



    Selected by Tim Fessenden

    1

    Tension on kinetochore substrates is insufficient to prevent Aurora-triggered detachment

    Anna K de Regt, Charles L Asbury, Sue Biggins



    Selected by Angika Basant

    1

    Single-cell RNA sequencing reveals novel cell differentiation dynamics during human airway epithelium regeneration

    Sandra Ruiz Garcia, Marie Deprez, Kevin Lebrigand, et al.



    Selected by Rob Hynds

    1

    Actomyosin-driven tension at compartmental boundaries orients cell division independently of cell geometry in vivo

    Elena Scarpa, Cedric Finet, Guy Blanchard, et al.



    Selected by Ivana Viktorinová

    Molecular organization of integrin-based adhesion complexes in mouse Embryonic Stem Cells

    Shumin Xia, Evelyn K.F. Yim, Pakorn Kanchanawong

    AND

    Superresolution architecture of pluripotency guarding adhesions

    Aki Stubb, Camilo Guzmán, Elisa Närvä, et al.



    Selected by Nicola Stevenson, Amanda Haage

    Transcriptional initiation and mechanically driven self-propagation of a tissue contractile wave during axis elongation

    Anais Bailles, Claudio Collinet, Jean-Marc Philippe, et al.



    Selected by Sundar Naganathan

    1

    Bridging the divide: bacteria synthesizing archaeal membrane lipids

    Laura Villanueva, F. A. Bastiaan von Meijenfeldt, Alexander B. Westbye, et al.

    AND

    Extensive transfer of membrane lipid biosynthetic genes between Archaea and Bacteria

    Gareth A. Coleman, Richard D. Pancost, Tom A. Williams



    Selected by Gautam Dey

    1

    Revealing the nanoscale morphology of the primary cilium using super-resolution fluorescence microscopy

    Joshua Yoon, Colin J. Comerci, Lucien E. Weiss, et al.



    Selected by Gautam Dey

    Lysosome exocytosis is required for mitosis

    Charlotte Nugues, Nordine Helassa, Robert Burgoyne, et al.



    Selected by claudia conte

    Three-dimensional tissue stiffness mapping in the mouse embryo supports durotaxis during early limb bud morphogenesis

    Min Zhu, Hirotaka Tao, Mohammad Samani, et al.



    Selected by Natalie Dye

    PUMILIO hyperactivity drives premature aging of Norad-deficient mice

    Florian Kopp, Mehmet Yalvac, Beibei Chen, et al.



    Selected by Carmen Adriaens

    3D Tissue elongation via ECM stiffness-cued junctional remodeling

    Dong-Yuan Chen, Justin Crest, Sebastian J Streichan, et al.



    Selected by Sundar Naganathan

    Transient intracellular acidification regulates the core transcriptional heat shock response

    Catherine G Triandafillou, Christopher D Katanski, Aaron R Dinner, et al.



    Selected by Srivats Venkataramanan

    1

    Budding yeast complete DNA replication after chromosome segregation begins

    Tsvetomira Ivanova, Michael Maier, Alsu Missarova, et al.



    Selected by Gautam Dey, Maiko Kitaoka

    Developmental heterogeneity of microglia and brain myeloid cells revealed by deep single-cell RNA sequencing

    Qingyun Li, Zuolin Cheng, Lu Zhou, et al.



    Selected by Zheng-Shan Chong

    Also in the developmental biology category:

    A histidine kinase gene is required for large radius root tip circumnutation and surface exploration in rice

    Kevin R Lehner, Isaiah Taylor, Erin N McCaskey, et al.



    Selected by Martin Balcerowicz

    Actomyosin-driven tension at compartmental boundaries orients cell division independently of cell geometry in vivo

    Elena Scarpa, Cedric Finet, Guy Blanchard, et al.



    Selected by Ivana Viktorinová

    Molecular organization of integrin-based adhesion complexes in mouse Embryonic Stem Cells

    Shumin Xia, Evelyn K.F. Yim, Pakorn Kanchanawong

    AND

    Superresolution architecture of pluripotency guarding adhesions

    Aki Stubb, Camilo Guzmán, Elisa Närvä, et al.



    Selected by Nicola Stevenson, Amanda Haage

    Transcriptional initiation and mechanically driven self-propagation of a tissue contractile wave during axis elongation

    Anais Bailles, Claudio Collinet, Jean-Marc Philippe, et al.



    Selected by Sundar Naganathan

    1

    Revealing the nanoscale morphology of the primary cilium using super-resolution fluorescence microscopy

    Joshua Yoon, Colin J. Comerci, Lucien E. Weiss, et al.



    Selected by Gautam Dey

    Signaling dynamics control cell fate in the early Drosophila embryo

    Heath E Johnson, Stanislav Y Shvartsman, Jared E Toettcher



    Selected by Yara E. Sánchez Corrales

    1

    Three-dimensional tissue stiffness mapping in the mouse embryo supports durotaxis during early limb bud morphogenesis

    Min Zhu, Hirotaka Tao, Mohammad Samani, et al.



    Selected by Natalie Dye

    PUMILIO hyperactivity drives premature aging of Norad-deficient mice

    Florian Kopp, Mehmet Yalvac, Beibei Chen, et al.



    Selected by Carmen Adriaens

    Synergy with TGFβ ligands switches WNT pathway dynamics from transient to sustained during human pluripotent cell differentiation

    Joseph Massey, Yida Liu, Omar Alvarenga, et al.



    Selected by Pierre Osteil

    1

    3D Tissue elongation via ECM stiffness-cued junctional remodeling

    Dong-Yuan Chen, Justin Crest, Sebastian J Streichan, et al.



    Selected by Sundar Naganathan

    EGFR signaling coordinates patterning with cell survival during Drosophila epidermal development

    Samuel Henry Crossman, Sebastian J Streichan, Jean-Paul Vincent



    Selected by Sarah Bowling

    1

    Damage-induced reactive oxygen species enable zebrafish tail regeneration by repositioning of Hedgehog expressing cells.

    Henry Roehl, Montserrat Garcia Romero, Gareth McCathie, et al.



    Selected by Alberto Rosello-Diez

    Arterio-Venous Remodeling in the Zebrafish Trunk Is Controlled by Genetic Programming and Flow-Mediated Fine-Tuning

    Ilse Geudens, Baptiste Coxam, Silvanus Alt, et al.



    Selected by Andreas van Impel

    Polyacrylamide Bead Sensors for in vivo Quantification of Cell-Scale Stress in Zebrafish Development

    Nicole Traeber, Klemens Uhlmann, Salvatore Girardo, et al.



    Selected by Jacky G. Goetz

    millepattes micropeptides are an ancient developmental switch required for embryonic patterning

    Suparna Ray, Miriam I Rosenberg, Hélène Chanut-Delalande, et al.



    Selected by Erik Clark

    Aurora A depletion reveals centrosome-independent polarization mechanism in C. elegans

    Kerstin Klinkert, Nicolas Levernier, Peter Gross, et al.

    AND

    Centrosome Aurora A gradient ensures a single PAR-2 polarity axis by regulating RhoGEF ECT-2 localization in C. elegans embryos

    Sachin Kotak, Sukriti Kapoor



    Selected by Giuliana Clemente

    Also in the genetics category:

    Evidence for an Integrated Gene Repression Mechanism based on mRNA Isoform Toggling in Human Cells

    Ina Hollerer, Juliet C Barker, Victoria Jorgensen, et al.



    Selected by Clarice Hong

    Signaling dynamics control cell fate in the early Drosophila embryo

    Heath E Johnson, Stanislav Y Shvartsman, Jared E Toettcher



    Selected by Yara E. Sánchez Corrales

    1

    PUMILIO hyperactivity drives premature aging of Norad-deficient mice

    Florian Kopp, Mehmet Yalvac, Beibei Chen, et al.



    Selected by Carmen Adriaens

    Arterio-Venous Remodeling in the Zebrafish Trunk Is Controlled by Genetic Programming and Flow-Mediated Fine-Tuning

    Ilse Geudens, Baptiste Coxam, Silvanus Alt, et al.



    Selected by Andreas van Impel

    CRISPR/Cas9-mediated gene deletion of the ompA gene in an Enterobacter gut symbiont impairs biofilm formation and reduces gut colonization of Aedes aegypti mosquitoes

    Shivanand Hegde, Pornjarim Nilyanimit, Elena Kozlova, et al.



    Selected by Snehal Kadam

    millepattes micropeptides are an ancient developmental switch required for embryonic patterning

    Suparna Ray, Miriam I Rosenberg, Hélène Chanut-Delalande, et al.



    Selected by Erik Clark

    Neural crest cells regulate optic cup morphogenesis by promoting extracellular matrix assembly

    Chase Dallas Bryan, Rebecca Lynne Pfeiffer, Bryan William Jones, et al.



    Selected by Ashrifia Adomako-Ankomah

    1

    The cis-regulatory logic underlying abdominal Hox-mediated repression versus activation of regulatory elements in Drosophila

    Arya Zandvakili, Juli Uhl, Ian Campbell, et al.



    Selected by Clarice Hong

    1

    Dynamic control of proinflammatory cytokines Il-1β and Tnf-α by macrophages is necessary for functional spinal cord regeneration in zebrafish

    Themistoklis M. Tsarouchas, Daniel Wehner, Leonardo Cavone, et al.



    Selected by Shikha Nayar

    1

    JNK-mediated spindle reorientation in stem cells promotes dysplasia in the aging intestine

    Daniel Hu, Heinrich Jasper



    Selected by Maiko Kitaoka

    Phenotypic landscape of schizophrenia-associated genes defines candidates and their shared functions

    Summer B. Thyme, Lindsey M. Pieper, Eric H. Li, et al.



    Selected by Daniel Grimes

    Super-Mendelian inheritance mediated by CRISPR/Cas9 in the female mouse germline

    Hannah A. Grunwald, Valentino M. Gantz, Gunnar Poplawski, et al.



    Selected by Rebekah Tillotson

    1

    The Ly6/uPAR protein Bouncer is necessary and sufficient for species-specific fertilization

    Sarah Herberg, Krista R Gert, Alexander Schleiffer, et al.



    Selected by James Gagnon

    Functional testing of a human PBX3 variant in zebrafish reveals a potential modifier role in congenital heart defects

    Gist H. Farr III, Kimia Imani, Darren Pouv, et al.



    Selected by Hannah Brunsdon

    A robust method for transfection in choanoflagellates illuminates their cell biology and the ancestry of animal septins

    David Booth, Heather Middleton, Nicole King



    Selected by Maya Emmons-Bell

    SWI/SNF remains localized to chromatin in the presence of SCHLAP1

    Jesse R Raab, Keriayn N Smith, Camarie C Spear, et al.



    Selected by Carmen Adriaens

    1

    Also in the molecular biology category:

    Signaling dynamics control cell fate in the early Drosophila embryo

    Heath E Johnson, Stanislav Y Shvartsman, Jared E Toettcher



    Selected by Yara E. Sánchez Corrales

    1

    PUMILIO hyperactivity drives premature aging of Norad-deficient mice

    Florian Kopp, Mehmet Yalvac, Beibei Chen, et al.



    Selected by Carmen Adriaens

    Target-specific precision of CRISPR-mediated genome editing

    Anob M Chakrabarti, Tristan Henser-Brownhill, Josep Monserrat, et al.



    Selected by Rob Hynds

    1

    Transient intracellular acidification regulates the core transcriptional heat shock response

    Catherine G Triandafillou, Christopher D Katanski, Aaron R Dinner, et al.



    Selected by Srivats Venkataramanan

    1

    Memory sequencing reveals heritable single cell gene expression programs associated with distinct cellular behaviors

    Sydney M Shaffer, Benjamin L Emert, Ann E. Sizemore, et al.



    Selected by Leighton Daigh

    1

    Site-specific K63 ubiquitinomics reveals post-initiation regulation of ribosomes under oxidative stress

    Songhee Back, Christine Vogel, Gustavo M Silva



    Selected by Srivats Venkataramanan

    1

    Quantitative, real-time, single cell analysis in tissue reveals expression dynamics of neurogenesis

    Cerys S Manning, Veronica Biga, James Boyd, et al.



    Selected by Teresa Rayon

    The cis-regulatory logic underlying abdominal Hox-mediated repression versus activation of regulatory elements in Drosophila

    Arya Zandvakili, Juli Uhl, Ian Campbell, et al.



    Selected by Clarice Hong

    1

    Moving beyond P values: Everyday data analysis with estimation plots

    Joses Ho, Tayfun Tumkaya, Sameer Aryal, et al.



    Selected by Gautam Dey

    1

    A limited number of double-strand DNA breaks are sufficient to delay cell cycle progression.

    Jeroen van den Berg, Anna G. Manjon, Karoline Kielbassa, et al.



    Selected by Leighton Daigh

    Template switching causes artificial junction formation and false identification of circular RNAs

    Chong Tang, Tian Yu, Yeming Xie, et al.



    Selected by Fabio Liberante

    Dynamics and interactions of ADP/ATP transporter AAC3 in DPC detergent are not functionally relevant

    Vilius Kurauskas, Audrey Hessel, François Dehez, et al.

    AND

    Major concerns with the integrity of the mitochondrial ADP/ATP carrier in dodecyl-phosphocholine used for solution NMR studies

    Martin S. King, Paul G. Crichton, Jonathan J. Ruprecht, et al.



    Selected by Reid Alderson

    1

    Targeting light-gated chloride channels to neuronal somatodendritic domain reduces their excitatory effect in the axon

    Jessica Messier, Hongmei Chen, Zhao-Lin Cai, et al.

    AND

    High-efficiency optogenetic silencing with soma-targeted anion-conducting channelrhodopsins

    Mathias Mahn, Lihi Gibor, Katayun Cohen-Kashi Malina, et al.



    Selected by Mahesh Karnani

    2

    Glutamic acid is a carrier for hydrazine during the biosyntheses of fosfazinomycin and kinamycin

    Kwo-Kwang Abraham Wang, Tai L. Ng, Peng Wang, et al.



    Selected by Ellis O'Neill

    The Histone H3-H4 Tetramer is a Copper Reductase Enzyme

    Narsis Attar, Oscar A Campos, Maria Vogelauer, et al.



    Selected by Lauren Neves

    Super-Mendelian inheritance mediated by CRISPR/Cas9 in the female mouse germline

    Hannah A. Grunwald, Valentino M. Gantz, Gunnar Poplawski, et al.



    Selected by Rebekah Tillotson

    1

    Close