Name: probing the roles of physical forces in early chick embryonic morphogenesis
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Description: Watch this Scientific Journal Video about Probing the Roles of Physical Forces in Early Chick Embryonic Morphogenesis at JoVE.com

Z.C. acknowledges the support from Dartmouth startup fund and the Branco Weiss- Society for Science fellowship, administered by ETH Zurich. The authors thank Drs. Larry A. Taber, Benjamen A. Filas, Qiaohang Guo, and Yunfei Shi for helpful discussions, as well as the anonymous reviewers for comments.&#160;This material is based upon work supported by the National Science Foundation Graduate Research Fellowship under Grant No. DGE-1313911. Any opinion, findings, and conclusions or recommendations expressed in this material are those of the authors(s) and do not necessarily reflect the views of the National Science Foundation.&#160;

1. Preparation of Tissue Culture Media
<ol>
	<li>Use a 0.5 L bottle of Dulbecco&#39;s Modified Eagle&#39;s Medium (DMEM) with 4.5 g/L glucose, sodium bicarbonate, and L-glutamine as the base for the culture media.</li>
	<li>In a sterile laminar flow hood, add 10 mL of antibiotics to the 0.5 L of DMEM.</li>
	<li>Using a sterile pipette, transfer 50 mL of the DMEM antibiotics solution to a sterile 50 mL conical tube.</li>
	<li>Add 50 mL of chick serum to the remaining DMEM antibiotics solution in the 0.5 L bottle in the ...

<ol>
	<li>Taber, L. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biomechanics+of+Growth,+Remodeling,+and+Morphogenesis.">Biomechanics of Growth, Remodeling, and Morphogenesis.</a> Appl. Mech. Rev. 48, 487-545 (1995).</li><li>Wyczalkowski, M. A., Chen, Z., Filas, B. A., Varner, V. D., Taber, L. 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Eng. 136, 1-15 (2014).</li><li>Shi, Y., 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=Bending+and+twisting+the+embryonic+heart:+A+computational+model+for+c-looping+based+on+realistic+geometry.">Bending and twisting the embryonic heart: A computational model for c-looping based on realistic geometry.</a> Front. Physiol. 5, (2014).</li><li>Taber, L. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Morphomechanics:+Transforming+tubes+into+organs.">Morphomechanics: Transforming tubes into organs.</a> Current Opinion in Genetics and Development. 27, 7-13 (2014).</li><li>Hosseini, H. S., Beebe, D. C., Taber, L. 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M., Alvarez-Bolado, G., Treichel, D., Gruss, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rotatin+is+a+novel+gene+required+for+axial+rotation+and+left-right+specification+in+mouse+embryos.">Rotatin is a novel gene required for axial rotation and left-right specification in mouse embryos.</a> Mech. Dev. 113, 15-28 (2002).</li><li>Yalcin, H. C., Shekhar, A., Rane, A. a., Butcher, J. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+ex-ovo+chicken+embryo+culture+system+suitable+for+imaging+and+microsurgery+applications.">An ex-ovo chicken embryo culture system suitable for imaging and microsurgery applications.</a> J. Vis. Exp. (44), (2010).</li><li>Chapman, S. C., Collignon, J., Schoenwolf, G. C., Lumsden, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improved+method+for+chick+whole-embryo+culture+using+a+filter+paper+carrier.">Improved method for chick whole-embryo culture using a filter paper carrier.</a> Dev. Dyn. 220, 284-289 (2001).</li><li>Camp&#224;s, O., 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=Quantifying+cell-generated+mechanical+forces+within+living+embryonic+tissues.">Quantifying cell-generated mechanical forces within living embryonic tissues.</a> Nat. 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A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+role+of+mechanical+forces+in+dextral+rotation+during+cardiac+looping+in+the+chick+embryo.">The role of mechanical forces in dextral rotation during cardiac looping in the chick embryo.</a> Dev. Biol. 272, 339-350 (2004).</li><li>Raya, A., Izpisua Belmonte, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Unveiling+the+establishment+of+left-right+asymmetry+in+the+chick+embryo.">Unveiling the establishment of left-right asymmetry in the chick embryo.</a> Mechanisms of Development. 121, 1043-1054 (2004).</li><li>Voronov, D. A., Taber, L. 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Appl. 5, (2016).</li><li>Manner, J., Seidl, W., Steding, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Formation+of+the+cervical+flexure:+an+experimental+study+on+chick+embryos.">Formation of the cervical flexure: an experimental study on chick embryos.</a> Acta Anat. (Basel). 152, 1-10 (1995).</li><li>Ware, M., Schubert, F. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+the+early+axon+scaffold+in+the+rostral+brain+of+the+chick+embryo.">Development of the early axon scaffold in the rostral brain of the chick embryo.</a> J. 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While physical phenomena play an integral role in morphogenesis26,27,28,29,30, the specific mechanical mechanisms, along with the coordination of mechanical and molecular mechanisms, remain largely unexplored. It is known that the ventral flexure and rightward torsion of the primitive brain are two central processes that contribute to early embryonic morphogen...

Modern developmental biology research largely focuses on understanding development from the perspective of molecular genetics1,2,3,4,5,6,7,8,9,10,11,12,13. It is known that physical phenomena play a central role in morphogenesis, or the generation of biological form14,15,16,17; however, specific mechanical mechanisms of development remain largely unstudied. Ventral flexure and rightward torsion of the primitive brain tube after Hamburger-Hamilton stage 11 (HH 11)18 are the two main processes that contribute to embryonic shape change19,20. In particular, the physical mechanism underlying the torsional development in the embryonic brain remains incompletely understood.
The embryonic torsion in chick embryo is among the earliest morphogenetic events of left-right (L-R) asymmetry in development. When the process of L-R asymmetry is perturbed, birth defects such as situs inversus, isomerism, or heterotaxia will occur21. 
Here we present a protocol which combines ex-ovo experiments22,23 with physical modeling to characterize mechanical forces during early embryonic brain development. The goal of the method presented is to identify the mechanical forces responsible for brain torsion and the factors that affect the degree of torsion during early development12. Based on the experimental observation that the vitelline membrane (VM) constrains the dorsal side of the embryo, we hypothesized that the VM provides the force necessary to induce torsion of the developing brain. Therefore, in this method, we removed the part of the VM that covers the brain area to find out the effects on brain torsion. Furthermore, the method of applying fluid surface tension was used to confirm the mechanical role of the VM and provide an estimate of the force needed for brain torsion, which had not been done previously. Measuring the forces during embryonic morphogenesis is a challenging task. Notably, in a pioneering study, Camp&#224;s and co-workers24 developed a novel method to quantify the cellular stresses using injected microdroplets. Nevertheless, this method was limited to measure forces at the cellular level, hence not applicable to probe forces at tissue- or organism-level. The protocol presented in this paper was developed to partially fill this gap.

<table border="0" cellpadding="0" cellspacing="0" width="751">
	<tbody>
		<tr height="42">
			<td height="42" style="height:42px;width:288px;">Fertilized Specific pathogen-free White Leghorn chicken eggs</td>
			<td style="width:177px;">Charles River</td>
			<td style="width:119px;"></td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:288px;">Optical Coherent Tomography Microscope</td>
			<td style="width:177px;">Thorlabs</td>
			<td style="width:119px;">GAN220C1</td>
			<td></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:20px;width:288px;">Silicone elastomer</td>
			<td style="width:177px;">Smooth-On, Inc.</td>
			<td style="width:119px;">EcoFlex 00-50</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:288px;">Dissecting microscope</td>
			<td style="width:177px;">Leica</td>
			<td style="width:119px;">MZ8</td>
			<td></td>
		</tr>
		<tr height="39">
			<td height="39" style="height:39px;width:288px;">Dulbecco&#8217;s Modified Eagle&#8217;s Medium (DMEM)</td>
			<td style="width:177px;">Lonza</td>
			<td style="width:119px;">12-604F</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:288px;">Antibiotics</td>
			<td style="width:177px;">Sigma</td>
			<td style="width:119px;">P4083</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:288px;">Chick serum</td>
			<td style="width:177px;">Sigma</td>
			<td style="width:119px;">C5405</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:288px;">Micropipette puller</td>
			<td style="width:177px;">Sutter Instrument</td>
			<td style="width:119px;">Model P-30</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:288px;">Filter paper</td>
			<td style="width:177px;">Whatman</td>
			<td style="width:119px;">5202-110</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:288px;">Phosphate buffered saline (PBS)</td>
			<td style="width:177px;">Corning</td>
			<td style="width:119px;">21-040-CV</td>
			<td></td>
		</tr>
		<tr height="23">
			<td height="23" style="height:23px;width:288px;">Comsol MultiPhysics</td>
			<td style="width:177px;">Comsol</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:288px;">3D computer graphics software</td>
			<td style="width:177px;">Rhino 5</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:288px;">Microscope attached with OCT</td>
			<td style="width:177px;">Nikon&#160;</td>
			<td style="width:119px;">FN1</td>
			<td></td>
		</tr>
		<tr height="18">
			<td height="18" style="height:18px;width:288px;">Digital single-lens reflex camera</td>
			<td style="width:177px;">EOS&#160;</td>
			<td style="width:119px;">Rebel T3i</td>
			<td></td>
		</tr>
	</tbody>
</table>

probing the roles of physical forces in early chick embryonic morphogenesis

Embryonic development is traditionally studied from the perspective of biomolecular genetics, but the fundamental importance of mechanics in morphogenesis is becoming increasingly recognized. In particular, the embryonic chick heart and brain tube, which undergo drastic morphological changes as they develop, are among the prime candidates to study the role of physical forces in morphogenesis. Progressive ventral bending&#160;and rightward torsion of the tubular embryonic chick brain happen at the earliest stage of organ-level left-right asymmetry in chick embryonic development. The vitelline membrane (VM) constrains the dorsal side of the embryo and has been implicated in providing the force necessary to induce torsion of the developing brain. Here we present a combination of new ex-ovo experiments and physical modeling to identify the mechanics of brain torsion. At Hamburger-Hamilton stage 11, embryos are harvested and cultured ex ovo (in media). The VM is subsequently removed using a pulled capillary tube. By controlling the level of the fluid and subjecting the embryo to a fluid-air interface, the fluid surface tension of the media can be used to replace the mechanical role of the VM. Microsurgery experiments were also performed to alter the position of the heart to find the resultant change in the chirality of brain torsion. Results from this protocol illustrate the fundamental roles of mechanics in driving morphogenesis.

In this study, the VM of the embryo at HH11 was removed from the anterior end to the thoracic flexure. The embryos were imaged by an OCT system. At this stage, the torsion of brain tube has not started (Figure 1A). After being incubated to HH15-16, embryos with their VM removed exhibited reduced brain tube torsion, approximately 35 degrees (Figure 1B) compared to control embryos, which exhibit torsion of around 90 degrees. When t...

Watch this Scientific Journal Video about Probing the Roles of Physical Forces in Early Chick Embryonic Morphogenesis at JoVE.com

Probing the Roles of Physical Forces in Early Chick Embryonic Morphogenesis

Here, we present a protocol introducing a set of new ex-ovo experiments and physical modeling approaches for studying the mechanics of morphogenesis during early chick embryonic brain torsion.

Embryonic development is traditionally studied from the perspective of biomolecular genetics, but the fundamental importance of mechanics in morphogenesis ...

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Remote Magnetic Actuation of Micrometric Probes for in situ 3D Mapping of Bacterial Biofilm Physical Properties

Bacterial adhesion and growth on interfaces lead to the formation of three-dimensional heterogeneous structures so-called biofilms. The cells dwelling in ...

Quantification of Global Diastolic Function by Kinematic Modeling-based Analysis of Transmitral Flow via the Parametrized Diastolic Filling Formalism

Quantitative cardiac function assessment remains a challenge for physiologists and clinicians.&#160;Although historically invasive methods have comprised ...

A Protocol for Using F&#246;rster Resonance Energy Transfer (FRET)-force Biosensors to Measure Mechanical Forces across the Nuclear LINC Complex

A Protocol for Using FÃƒÆ’Ã†'Ãƒâ€šÃ‚Â¶rster Resonance Energy Transfer FRET-force Biosensors to Measure Mechanical Forces across the Nuclear LINC Complex

The LINC complex has been hypothesized to be the critical structure that mediates the transfer of mechanical forces from the cytoskeleton to the nucleus. ...

A High-throughput Cell Microarray Platform for Correlative Analysis of Cell Differentiation and Traction Forces

Microfabricated cellular microarrays, which consist of contact-printed combinations of biomolecules on an elastic hydrogel surface, provide a tightly ...

An In Vitro Organ Culture Model of the Murine Intervertebral Disc

An In Vitro Organ Culture Model of the Murine Intervertebral Disc

Intervertebral disc (IVD) degeneration is a significant contributor to low back pain. The IVD is a fibrocartilaginous joint that serves to transmit and ...

Improved 3D Hydrogel Cultures of Primary Glial Cells for In Vitro Modelling of Neuroinflammation

Improved 3D Hydrogel Cultures of Primary Glial Cells for In Vitro Modelling of Neuroinflammation

In the central nervous system, numerous acute injuries and neurodegenerative disorders, as well as implanted devices or biomaterials engineered to enhance ...

A Tripeptide-Stabilized Nanoemulsion of Oleic Acid

We describe a method to produce a nanoemulsion composed of an oleic acids-Pt(II) core and a lysine-tyrosine-phenylalanine (KYF) coating (KYF-Pt-NE). The ...

Patterning the Geometry of Human Embryonic Stem Cell Colonies on Compliant Substrates to Control Tissue-Level Mechanics

Human embryonic stem cells demonstrate a unique ability to respond to morphogens in vitro by self-organizing patterns of cell fate specification that ...

Application of Atomic Force Microscopy to Detect Early Osteoarthritis

Biomechanical properties of cells and tissues not only regulate their shape and function but are also crucial for maintaining their vitality. Changes in ...