We thank Dr. Gaudenz Danuser and members of his lab for creating the plusTipTracker software and for helpful discussion regarding using the software, in particular Maria Bagonis and Sebastien Besson. We especially thank the Boston College Media Center for their assistance and support in the creation and editing of the video. We also thank members of the Lowery Lab for useful discussions and constructive criticism, and Abigail Antoine for proof-reading the manuscript. This work was funded by an NIH R00 MH095768 award to LAL.

This protocol and video are meant to serve as a companion to the original paper describing the software package in more detail4, as well as the Technical Report that comes with the software download on the Danuser Lab website. Readers are encouraged to review these documents carefully if there are additional questions regarding using the software.
1. Prior to Image Analysis
<ol>
	<li>Convert each time-lapse movie into a sequence of TIFF (Tagged Image File Format) image files. If t...

<ol>
	<li>Stepanova, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Visualization+of+microtubule+growth+in+cultured+neurons+via+the+use+of+EB3-GFP+(end-binding+protein+3-green+fluorescent+protein).">Visualization of microtubule growth in cultured neurons via the use of EB3-GFP (end-binding protein 3-green fluorescent protein).</a> The Journal of neuroscience : the official journal of the Society for Neuroscience. 23, 2655-2664 (2003).</li><li>Lee, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+microtubule+plus+end+tracking+protein+Orbit/MAST/CLASP+acts+downstream+of+the+tyrosine+kinase+Abl+in+mediating+axon+guidance.">The microtubule plus end tracking protein Orbit/MAST/CLASP acts downstream of the tyrosine kinase Abl in mediating axon guidance.</a> Neuron. , 913-926 (2004).</li><li>Purro, S. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Wnt+regulates+axon+behavior+through+changes+in+microtubule+growth+directionality:+a+new+role+for+adenomatous+polyposis+coli.">Wnt regulates axon behavior through changes in microtubule growth directionality: a new role for adenomatous polyposis coli.</a> The Journal of neuroscience : the official journal of the Society for Neuroscience. 28, 8644-8654 (2008).</li><li>Applegate, K. T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=plusTipTracker:+Quantitative+image+analysis+software+for+the+measurement+of+microtubule+dynamics.">plusTipTracker: Quantitative image analysis software for the measurement of microtubule dynamics.</a> Journal of structural biology. 176, 168-184 (2011).</li><li>Lowery, L. A., Faris, A. E., Stout, A., Van Vactor, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neural+Explant+Cultures+from+Xenopus+laevis.">Neural Explant Cultures from Xenopus laevis.</a> Journal of visualized experiments : JoVE. (68), e4232 (2012).</li><li>Long, J. B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multiparametric+analysis+of+CLASP-interacting+protein+functions+during+interphase+microtubule+dynamics.">Multiparametric analysis of CLASP-interacting protein functions during interphase microtubule dynamics.</a> Molecular and cellular biology. 33, 1528-1545 (2013).</li><li>Myers, K. A., Applegate, K. T., Danuser, G., Fischer, R. S., Waterman, C. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Distinct+ECM+mechanosensing+pathways+regulate+microtubule+dynamics+to+control+endothelial+cell+branching+morphogenesis.">Distinct ECM mechanosensing pathways regulate microtubule dynamics to control endothelial cell branching morphogenesis.</a> The Journal of cell biology. 192, 321-334 (2011).</li><li>Nishimura, Y., Applegate, K., Davidson, M. W., Danuser, G., Waterman, C. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Automated+screening+of+microtubule+growth+dynamics+identifies+MARK2+as+a+regulator+of+leading+edge+microtubules+downstream+of+Rac1+in+migrating+cells.">Automated screening of microtubule growth dynamics identifies MARK2 as a regulator of leading edge microtubules downstream of Rac1 in migrating cells.</a> PLoS One. 7, e41413 (2012).</li><li>Akhmanova, A., Steinmetz, M. O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tracking+the+ends:+a+dynamic+protein+network+controls+the+fate+of+microtubule+tips.">Tracking the ends: a dynamic protein network controls the fate of microtubule tips.</a> Nature reviews. Molecular cell biology. 9, 309-322 (2008).</li><li>Schuyler, S. C., Pellman, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microtubule+'plus-end-tracking+proteins':+The+end+is+just+the+beginning.">Microtubule 'plus-end-tracking proteins': The end is just the beginning.</a> Cell. 105, 421-424 (2001).</li><li>Mitchison, T., Kirschner, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dynamic+instability+of+microtubule+growth.">Dynamic instability of microtubule growth.</a> Nature. 312, 237-242 (1984).</li><li>Mimori-Kiyosue, Y., Shiina, N., Tsukita, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+dynamic+behavior+of+the+APC-binding+protein+EB1+on+the+distal+ends+of+microtubules.">The dynamic behavior of the APC-binding protein EB1 on the distal ends of microtubules.</a> Current biology : CB. 10, 865-868 (2000).</li><li>Dixit, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microtubule+plus-end+tracking+by+CLIP-170+requires+EB1.">Microtubule plus-end tracking by CLIP-170 requires EB1.</a> Proceedings of the National Academy of Sciences of the United States of America. 106, 492-497 (2009).</li><li>Li, W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=EB1+promotes+microtubule+dynamics+by+recruiting+Sentin+in+Drosophila+cells.">EB1 promotes microtubule dynamics by recruiting Sentin in Drosophila cells.</a> The Journal of cell biology. 193, 973-983 (2011).</li><li>Maurer, S. P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=EB1+accelerates+two+conformational+transitions+important+for+microtubule+maturation+and+dynamics.">EB1 accelerates two conformational transitions important for microtubule maturation and dynamics.</a> Current biology : CB. 24, 372-384 (2014).</li><li>Zanic, M., Widlund, P. O., Hyman, A. A., Howard, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synergy+between+XMAP215+and+EB1+increases+microtubule+growth+rates+to+physiological+levels.">Synergy between XMAP215 and EB1 increases microtubule growth rates to physiological levels.</a> Nature cell biology. 15, 688-693 (2013).</li><li>Lowery, L. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Growth+cone-specific+functions+of+XMAP215+in+restricting+microtubule+dynamics+and+promoting+axonal+outgrowth.">Growth cone-specific functions of XMAP215 in restricting microtubule dynamics and promoting axonal outgrowth.</a> Neural development. 8, 22 (2013).</li><li>Marx, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Xenopus+cytoplasmic+linker-associated+protein+1+(XCLASP1)+promotes+axon+elongation+and+advance+of+pioneer+microtubules.">Xenopus cytoplasmic linker-associated protein 1 (XCLASP1) promotes axon elongation and advance of pioneer microtubules.</a> Molecular biology of the cell. 24, 1544-1558 (2013).</li></ol>

The authors declare that they have no competing financial interests.

PlusTipTracker provides a straightforward, graphical user interface to quickly and automatically detect virtually all visible EB1-GFP comets in a cell or growth cone, link the comets into tracks, and calculate MT parameters. Other publications have reported the design of similar types of software (for example, Marx et al. also utilized quantitative analysis of tagged EB1 dynamics in growth cones18). But, this software appears to be unique in its ease of access, as it is freely downloadable from the we...

The goal of this method is to obtain quantitative information regarding microtubule (MT) plus-end-tracking protein (+TIP) dynamics in living growth cones. MT +TIPs are a group of proteins that localize to the plus-ends of MTs9,10. They perform a range of functions to regulate parameters of MT dynamic instability11, including rates of polymerization, catastrophe, and rescue. One well-used method for analyzing MT dynamics is to track the behavior of the +TIP EB1, which binds specifically to growing MT plus-ends1,12. EB1 is known to recruit several other proteins to growing MT plus-ends13,14, and has recently been established as a MT maturation factor15, promoting both MT growth and catastrophe frequency15,16.
Many studies of MT dynamics within growth cones have utilized hand-tracking methods to measure changes in EB1-GFP dynamics over time1-3, as EB1 localization to MT plus-ends can be used as a marker for MT polymerization. A key benefit for examining EB1-GFP comets as a proxy for MT growth is that MT dynamics can be measured even in regions of significant MT overlap. While the method of hand-tracking EB1-GFP comets has provided useful insights into MT behaviors1-3, it is time-consuming and can be biased. Additionally, as aberrant growth cone behaviors are likely the result of minute shifts in cytoskeletal dynamics, analyzing only a small subset of MTs (usually necessary when hand-tracking) may miss significant information.
Thus, we measure global MT dynamics parameters using the software package, plusTipTracker4, after the acquisition of high-resolution, live images of tagged EB1 in cultured embryonic growth cones5. This software, developed in the Danuser Lab, has been used in several studies characterizing MT dynamics in various cell types6-8. It is an open-source, user-friendly, MATLAB-based package that includes automated detection, tracking, visualization, and analysis for movies of fluorescently-labeled +TIPs. A long list of specific parameters of MT dynamics are calculated by this software (see Reference 4 for details), but for analysis of MT dynamics in growth cones, the most useful parameters are MT growth track velocity (in microns/minute), growth track lifetime (in seconds), and growth track length (in microns). The software can be downloaded directly from the Danuser Lab website (under &#8220;Software&#8221;). While the Danuser Lab currently supports a newer interface for +TIP tracking analysis, which is incorporated into a software package called u-track 2.0, the original, stand-alone software will remain available. The underlying algorithms between the two programs are the same (at least as of 2014), with only a difference of interface and analysis outputs. For the novice user with little MATLAB&#160;and/or computational analysis experience, plusTipTracker has more user-friendly features, including automated statistical parameter outputs.
Here, we describe the steps for analyzing images of EB1-GFP dynamics in cultured Xenopus laevis growth cones. This protocol was utilized in a recent paper examining MT dynamics17. See also Lowery et al. 20125 for detailed instructions regarding culturing growth cones expressing EB1-GFP. While this paper primarily focused on examining EB1-GFP dynamics in growth cones, the same protocol can be used for other cell types17. For all cell types, the time interval between frames should be between 0.5-2 sec&#160;for optimal +TIP tracking. A time interval of up to 4 seconds between frames is possible, but this increased interval time results in additional tracking errors.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">plusTipTracker software</td>
			<td style="width:116px;">Danuser Lab</td>
			<td style="width:345px;"><a href="http://lccb.hms.harvard.edu/software.html">http://lccb.hms.harvard.edu/software.html</a></td>
			<td style="width:172px;">This software may be hosted by another website in the future.&#160; If the listed site does not exist, search &#34;Danuser Lab Software&#34; on a web search engine to find the site.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">Matlab software</td>
			<td style="width:116px;">Mathworks</td>
			<td><a href="http://www.mathworks.com/products/matlab/">http://www.mathworks.com/products/matlab/</a></td>
			<td></td>
		</tr>
	</tbody>
</table>

using plustiptracker software to measure microtubule dynamics in xenopus laevis growth cones

Microtubule (MT) plus-end-tracking proteins (+TIPs) localize to the growing plus-ends of MTs and regulate MT dynamics1,2. One of the most well-known and widely-utilized +TIPs for analyzing MT dynamics is the End-Binding protein, EB1, which binds all growing MT plus-ends, and thus, is a marker for MT polymerization1. Many studies of EB1 behavior within growth cones have used time-consuming and biased computer-assisted, hand-tracking methods to analyze individual MTs1-3. Our approach is to quantify global parameters of MT dynamics using the software package, plusTipTracker4, following the acquisition of high-resolution, live images of tagged EB1 in cultured embryonic growth cones5. This software is a MATLAB-based, open-source, user-friendly package that combines automated detection, tracking, visualization, and analysis for movies of fluorescently-labeled +TIPs. Here, we present the protocol for using plusTipTracker for the analysis of fluorescently-labeled +TIP comets in cultured Xenopus laevis growth cones. However, this software can also be used to characterize MT dynamics in various cell types6-8.

Using this software as described here will provide several files of information that quantify +TIP dynamics in living cells.
The function plusTipGetTracks identifies the tracks (using example settings shown in Figure 1), and then provides parameters regarding the +TIP tracks. To view the information that the software has obtained, go into the roi_X directory that was created in step 2.2. The &#8220;feat&#8221; folder contains &#8220;overlayImages&#8221;, which is a series of i...

Watch this Scientific Journal Video about Using plusTipTracker Software to Measure Microtubule Dynamics in Xenopus laevis Growth Cones at JoVE.com

Using plusTipTracker Software to Measure Microtubule Dynamics in Xenopus laevis Growth Cones

The MATLAB-based, open source software package, plusTipTracker, can be used to analyze image series of fluorescently-labeled +TIPs to quantify microtubule dynamics.

Using plusTipTracker Software to Measure Microtubule Dynamics in Xenopus laevis Growth Cones

Microtubule (MT) plus-end-tracking proteins (+TIPs) localize to the growing plus-ends of MTs and regulate MT dynamics1,2. One of the most well-known and ...

using-plustiptracker-software-to-measure-microtubule-dynamics-xenopus

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JoVE Journal

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10.3K visualizações.  Boston College.  A, pacote de código aberto baseado em software MATLAB, plusTipTracker, pode ser usado para análise de séries de imagem + TIPs marcados com fluorescência para quantificar dinâmica dos microtúbulos. 