The authors would like to thank Gregory Haller (Mount Saint Vincent University) for his preliminary work in the development of the protocol. The authors would also like to thank Nicholas Jones (Mount Saint Vincent University) for his technical expertise and assistance with the filming and production of the audio/visual portion of the manuscript. Daniel Andrews was supported by funding from MSVU and the Natural Sciences and Engineering Research Council of Canada (NSERC) via an Undergraduate Student Research Award. Tamara A. Franz-Odendaal is supported by an NSERC Discovery Grant.

NOTE: For embryo stages, utilize the Hamburger and Hamilton12 (HH) staging table.
1. Embryo Incubation
<ol>
	<li>Incubate fertilized chicken eggs in a sterile, temperature-controlled incubator at 37 &#176;C &#177; 1 &#176;C and ~40% humidity.</li>
	<li>Turn the eggs 1x per day and allow them to incubate to HH34 (8 days post-fertilization).</li>
</ol>
2. Preparation and Sterilization of the Materials
<ol>
	<li>For 12 embryos, autoclave 2 L of ...

<ol>
	<li>Franz-Odendaal, T. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Towards+understanding+the+development+of+scleral+ossicles+in+the+chicken,+Gallus+gallus.">Towards understanding the development of scleral ossicles in the chicken, Gallus gallus.</a> Developmental Dynamics. 237 (11), 3240-3251 (2008).</li><li>Scholey, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functions+of+motor+proteins+in+echinoderm+embryos:+an+argument+in+support+of+antibody+inhibition+experiments.">Functions of motor proteins in echinoderm embryos: an argument in support of antibody inhibition experiments.</a> Cell Motility and the Cytoskeleton. 39 (4), 257-260 (1998).</li><li>Horakova, D., 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=Effect+of+FGFR+inhibitors+on+chicken+limb+development.">Effect of FGFR inhibitors on chicken limb development.</a> Development, Growth &amp; Differentiation. 56 (8), 555-572 (2014).</li><li>Gerlach, G. F., Morales, E. E., Wingert, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microbead+Implantation+in+the+Zebrafish+Embryo.">Microbead Implantation in the Zebrafish Embryo.</a> Journal of Visualized Experiments. (101), e52943 (2015).</li><li>Luz-Madrigal, A., Grajales-Esquivel, E., Del Rio-Tsonis, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electroporation+of+Embryonic+Chick+Eyes.">Electroporation of Embryonic Chick Eyes.</a> Bio-protocol. 5 (12), e1498 (2015).</li><li>Roach, H. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Long-term+organ+culture+of+embryonic+chick+femora:+a+system+for+investigating+bone+and+cartilage+formation+at+an+intermediate+level+of+organization.">Long-term organ culture of embryonic chick femora: a system for investigating bone and cartilage formation at an intermediate level of organization.</a> Journal of Bone and Mineral Research. 5 (1), 85-100 (1990).</li><li>Jung, H. S., 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=Local+inhibitory+action+of+BMPs+and+their+relationships+with+activators+in+feather+formation:+implications+for+periodic+patterning.">Local inhibitory action of BMPs and their relationships with activators in feather formation: implications for periodic patterning.</a> Developmental Biology. 196 (1), 11-23 (1998).</li><li>McKinnell, I. W., Turmaine, M., Patel, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sonic+Hedgehog+functions+by+localizing+the+region+of+proliferation+in+early+developing+feather+buds.">Sonic Hedgehog functions by localizing the region of proliferation in early developing feather buds.</a> Developmental Biology. 272 (1), 76-88 (2004).</li><li>Smith, E. L., Kanczler, J. M., Oreffo, R. O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new+take+on+an+old+story:+chick+limb+organ+culture+for+skeletal+niche+development+and+regenerative+medicine+evaluation.">A new take on an old story: chick limb organ culture for skeletal niche development and regenerative medicine evaluation.</a> European Cells &amp; Materials. 26, 91-106 (2013).</li><li>Sato, 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=In+Vitro+Spermatogenesis+in+Explanted+Adult+Mouse+Testis+Tissues.">In Vitro Spermatogenesis in Explanted Adult Mouse Testis Tissues.</a> PLoS One. 10 (6), e0130171 (2015).</li><li>Ochoa-Villarreal, M., 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=Plant+cell+culture+strategies+for+the+production+of+natural+products.">Plant cell culture strategies for the production of natural products.</a> BMB Reports. 49 (3), 149-158 (2016).</li><li>Hamburger, V., Hamilton, H. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+series+of+normal+stages+in+the+development+of+the+chick+embryo.">A series of normal stages in the development of the chick embryo.</a> Journal of Morphology. 88 (1), 49-92 (1951).</li><li>Yu, M., 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+developmental+biology+of+feather+follicles.">The developmental biology of feather follicles.</a> The International Journal of Developmental Biology. 48, 181-191 (2004).</li><li>Jabalee, J., Hillier, S., Franz-Odendaal, T. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+investigation+of+cellular+dynamics+during+the+development+of+intramembranous+bones:+the+scleral+ossicles.">An investigation of cellular dynamics during the development of intramembranous bones: the scleral ossicles.</a> Journal of Anatomy. 223 (4), 311-320 (2013).</li><li>Trowell, O. 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+culture+of+mature+organs+in+a+synthetic+medium.">The culture of mature organs in a synthetic medium.</a> Experimental Cell Research. 16 (1), 118-147 (1959).</li><li>Pinto, C. B., Hall, B. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Toward+an+understanding+of+the+epithelial+requirement+for+osteogenesis+in+scleral+mesenchyme+of+the+embryonic+chick.">Toward an understanding of the epithelial requirement for osteogenesis in scleral mesenchyme of the embryonic chick.</a> Journal of Experimental Zoology. 259 (1), 92-108 (1991).</li><li>Mbiene, J. P., MacCallum, D. K., Mistretta, 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=Organ+cultures+of+embryonic+rat+tongue+support+tongue+and+gustatory+papilla+morphogenesis+in+vitro+without+intact+sensory+ganglia.">Organ cultures of embryonic rat tongue support tongue and gustatory papilla morphogenesis in vitro without intact sensory ganglia.</a> Journal of Comparative Neurology. 377 (3), 324-340 (1997).</li><li>Cloney, K., Franz-Odendaal, T. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optimized+ex-ovo+culturing+of+chick+embryos+to+advanced+stages+of+development.">Optimized ex-ovo culturing of chick embryos to advanced stages of development.</a> Journal of Visualized Experiments. (95), e52129 (2015).</li><li>Korn, M. J., Cramer, K. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Windowing+chicken+eggs+for+developmental+studies.">Windowing chicken eggs for developmental studies.</a> Journal of Visualized Experiments. (8), e306 (2007).</li></ol>

This protocol makes use of established tissue culturing techniques to achieve the growth of a chicken eye from embryonic day 8 (HH34) in vitro for 4 days. This grid-culturing method was originally described by Trowell15. We optimized a protocol from Pinto and Hall&#39;s 1991 study16 utilizing a semi-porous membrane with the grid to study inductive signals between separated tissue layers of the embryonic chicken eye15. Using this method, Roac...

The embryonic chicken (Gallus gallus) is an excellent model organism commonly used in the field of biology. Its incubation period is roughly 21 days and many eggs can be incubated simultaneously, making experimentation quick and efficient. Perhaps most importantly, the embryo is also easily manipulated, enabling the extensive study of key developmental processes and of the genes and proteins that drive these processes.
The embryonic chicken eye is a complex organ that develops via the interaction of a number of different tissues similar to many other body systems. This method enables the study of the development of these tissues, particularly at advanced stages of development. For example, the multi-layered retina may be of particular interest to those studying the development of the nervous system. Alternative methods that enable the study of other eye tissues such as the cornea, the vitreal body, the lens, the sclera, and the eyelids are of benefit to researchers. The chicken embryonic eye also contains a series of flat bones, the scleral ossicles, which can be used as a model for the study of intramembranous bone induction and ossification in vertebrates1.
Currently, there are a number of methods used to study embryonic development. Microinjections of inhibitory antibodies or other inhibitory molecules2,3, surgically implanted microbeads soaked in inhibitor4, and electroporation5 are all methods that can be used to downregulate genes or proteins of interest in an embryo. Similar methods are used to upregulate proteins. These methods are not without their limitations. For example, when using chemicals to alter the embryonic development, the lethal effects on the embryo must be evaluated, and this limits the use of the aforementioned methods to localized sites of application at doses low enough to ensure the survivability of the embryo.
In vitro tissue&#160;culturing has been used in a wide range of organisms to study development and can be used to bypass some of the aforementioned limitations. For example, the femora6, feather buds7,8, and limbs9 of the chicken have all been studied using tissue culturing methods, as have the testes of the mouse10 and the roots and stems of plants11. These methods grant scientists a high degree of control over the tissue development, such as the ability to fluctuate the temperature and alter the nutrient availability. The isolation of the tissue from the whole embryo also makes it far less susceptible to the lethal effects of chemicals, thus enabling manipulation studies on a global scale at higher concentrations. Another notable advantage of in vitro culturing is the preservation of the tissue&#39;s cellular environment; the arrangement of tissues remains relatively unchanged, making it possible to study the interactions between different tissue types9. Thus, in vitro culturing opens doors to additional experimental approaches not available in in vivo or in ovo models.
Currently, studying the development of the embryonic chicken eye using chemicals is particularly challenging. A number of extraembryonic membranes cover the embryo, making it difficult to apply microbeads or chemicals; the embryo is also very active within the egg as it gets older, further complicating an already difficult method. This protocol enables easy access to the eye and its surrounding tissues, eliminating these barriers, while also providing new opportunities to examine the developmental processes within the eye. This protocol was established to study the induction of the scleral ossicles within the embryonic eye.

<table border="0" cellpadding="0" cellspacing="0" style="width:1081px;" width="1082">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">35 mm cell culture petri dishes</td>
			<td style="width:71px;">Corning</td>
			<td style="width:119px;">353001</td>
			<td style="width:676px;">easy grip tissue culture dish, polystyrene, non-pyrogenic</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">100 mm cell culture petri dishes</td>
			<td style="width:71px;">Corning</td>
			<td style="width:119px;">353003</td>
			<td>tissue culture dish, polystyrene, non-pyrogenic</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">paper tissue</td>
			<td style="width:71px;">Kimtech</td>
			<td style="width:119px;">34155</td>
			<td>Kimtech Science Brand Task Wipers, 280 per carton</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">wire mesh</td>
			<td style="width:71px;">n/a</td>
			<td style="width:119px;">n/a</td>
			<td>stainless steel wire mesh (grid size 0.7 mm)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">disposable glass pipettes</td>
			<td style="width:71px;">VWR</td>
			<td style="width:119px;">14673-010</td>
			<td>Borosilicate glass disposable 5 3/4&#34;</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">nutrient medium</td>
			<td style="width:71px;">Gibco</td>
			<td style="width:119px;">12591-038</td>
			<td>Fitton-Jackson Modification, [+] L-glutamine with phenol red (BGJB)</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">penicillin-streptomycin</td>
			<td style="width:71px;">Sigma-Aldrich</td>
			<td style="width:119px;">P4458</td>
			<td>10000 units/mL penicillin streptomycin solution stabilised</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">filter paper</td>
			<td style="width:71px;">Whatman</td>
			<td style="width:119px;">1454 090</td>
			<td>semi-porous filter paper 90mm</td>
		</tr>
		<tr height="147">
			<td height="147" style="height:147px;width:216px;">fertilized chicken eggs</td>
			<td style="width:71px;">Dalhousie University Agricultural College</td>
			<td style="width:119px;">n/a</td>
			<td>can be obtained from local farms</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">sodium chloride (NaCl)</td>
			<td style="width:71px;">EMD</td>
			<td style="width:119px;">SX0420-3</td>
			<td>sodium chloride crystals, reagent grade</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">1 L glass bottle</td>
			<td style="width:71px;">VWR</td>
			<td style="width:119px;">89000-240</td>
			<td>1 L pyrex autoclavable glass bottle</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">ethanol</td>
			<td style="width:71px;">Fisher Scientific</td>
			<td>BP82011</td>
			<td>70% molecular biology grade</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">tupperware containers</td>
			<td style="width:71px;">n/a</td>
			<td style="width:119px;">n/a</td>
			<td>store-bought and sterilized with EtOH</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">disposable razor blades</td>
			<td style="width:71px;">VWR</td>
			<td style="width:119px;">55411-050</td>
			<td>single edge industrial razor blades (surgical carbon steel)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">plastic spoons</td>
			<td style="width:71px;">n/a</td>
			<td style="width:119px;">n/a</td>
			<td>store-bought and sterilized with EtOH</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">dust mask</td>
			<td style="width:71px;">3M</td>
			<td style="width:119px;">n/a</td>
			<td>3M 8500 Comfort Mask</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">paraformaldehyde</td>
			<td style="width:71px;">Sigma-Aldrich</td>
			<td style="width:119px;">P6148</td>
			<td>paraformaldehyde, reagent grade, crystalline</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">neutral-buffered formalin</td>
			<td style="width:71px;">Fisher Scientific</td>
			<td style="width:119px;">72210</td>
			<td>10% neutral buffered formalin</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">phosphate buffered saline (PBS)</td>
			<td style="width:71px;">n/a</td>
			<td style="width:119px;">n/a</td>
			<td>10X phosphate buffered saline pH 7.4 (137mM NaCl, 2.5mM KCl, 4.3mM Na2HPO4, 1.4mM KH2PO4)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">15 ml falcon tubes</td>
			<td style="width:71px;">VWR</td>
			<td style="width:119px;">21008-216</td>
			<td>presterilized centrifuge tubes</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">forceps</td>
			<td style="width:71px;">FST</td>
			<td style="width:119px;">n/a</td>
			<td>fine forceps</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">chick saline&#160;</td>
			<td style="width:71px;">n/a</td>
			<td style="width:119px;">n/a&#160;</td>
			<td>0.85% NaCl</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">tinfoil</td>
			<td style="width:71px;">n/a</td>
			<td style="width:119px;">n/a</td>
			<td>store-bought</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">paper towel</td>
			<td style="width:71px;">n/a</td>
			<td style="width:119px;">n/a</td>
			<td>store-bought</td>
		</tr>
	</tbody>
</table>

organotypic culture method to study the development of embryonic chicken tissues

The embryonic chicken is commonly used as a reliable model organism for vertebrate development. Its accessibility and short incubation period makes it ideal for experimentation. Currently, the study of these developmental pathways in the chicken embryo is conducted by applying inhibitors and drugs at localized sites and at low concentrations using a variety of methods. In vitro tissue&#160;culturing is a technique that enables the study of tissues separated from the host organism, while simultaneously bypassing many of the physical limitations present when working with whole embryos, such as the susceptibility of embryos to high doses of potentially lethal chemicals. Here, we present an organotypic culturing protocol for culturing the embryonic chicken half head in vitro, which presents new opportunities for the examination of developmental processes beyond the currently established methods.

Using this method, an embryonic chicken eye can be cultured from day 8 of its development (HH34) in vitro for 4 days. Four days of in ovo development corresponds to HH38.
This culturing method supports the development of feather buds surrounding the eye and&#160;on the eyelids (Figure 1B). These feather buds are not present in ovo at HH34 prior to the culturing (<strong cl...

Watch this Scientific Journal Video about Organotypic Culture Method to Study the Development Of Embryonic Chicken Tissues at JoVE.com

Organotypic Culture Method to Study the Development Of Embryonic Chicken Tissues

Here, we present an organotypic culturing protocol to grow embryonic chicken organs in vitro. Using this method, the development of embryonic chicken tissue can be studied, while maintaining a high degree of control over the culture environment.

The embryonic chicken is commonly used as a reliable model organism for vertebrate development. Its accessibility and short incubation period makes it ...

The overall goal of this protocol is to provide access to embryonic chicken eyes in an in-vitro setting to enable in-depth study of complex developmental pathways in the embryo. In the embryonic chicken, studying the eye is often difficult, due to eyelid development, embryo movement, and the growth of extra embryonic tissues. Compounds such as drugs and inhibitors can also have lethal effects on the embryo, making it difficult to use these compounds to modulate gene pathways.Advances in in-vitro tissue culturing have allowed scientists to isolate these tissues and eliminate many of these aforementioned barriers. Our protocol is advantageous in that it allows us to study the eye as a whole, including all of the tissues that have the potential to interact during development, such as the neural retina and the retinal pigmented epithelium. Begin by autoclaving the materials to ensure that all solutions and equipment are sterile prior to the procedure.To do this, autoclave two liters of distilled water and one liter of chick saline, along with a box of tissues, semi-porous filter paper, wire mesh, water containers, and disposable glass pipettes. Thoroughly sterilize the incubator shelves and door using 70%ethanol, then fill the containers with autoclaved, distilled water, and preheat the incubator to 37 degrees Celsius. Prewarm the nutrient medium, along with a tube of the antibiotic penicillin streptomycin in the incubator.Lay a paper towel across the workspace and sterilize with 70%ethanol. Sterilize all forceps and scissors. With the chicken head in autoclaved chick saline, bisect the chick head in the midline, leaving some tissue in tact around each eye.The extra tissue will help the eye maintain some tension in the culture, as well as assisting with nutrient uptake throughout the eye and preventing the eye from sliding off the filter paper. These tissues also serve as landmarks when orienting the eye in later analysis. Leave the dissected tissue in room-temperature chick saline while preparing the culture.Prepare the culture dish. Place two 35-millimeter Petri dishes inside one 100-millimeter Petri dish. Place one wire mesh stage in each small dish.Place the half-head with the eye onto a piece of filter paper, tilting slightly to ensure the eye will not slide off the paper. Transfer the tissue and filter paper to the small Petri dish atop the wire mesh stage. Repeat with the other half-head of the same embryo.Add culture medium to each of the two small Petri dishes. Bring the medium up to the level of the tissue paper. Do not submerge the tissue in the medium.Add 50 microliters of the antibiotic penicillin streptomycin stock solution to the nutrient medium in each dish in order to prevent bacterial infection. Place a folded piece of thin tissue on the inner edge of the larger Petri dish and moisten it with distilled water. Incubate the culture in the dark incubator at 37 degrees Celsius for up to four days.Following culturing, remove the tissue from the filter paper and fix in 4%paraformaldehyde. The first column shows an HH34 eye, representing the embryonic chick eye at the beginning of culturing. The second column shows an embryonic chick eye cultured for four days, beginning at HH34.The third column shows an HH38 eye, which corresponds to four days of in-ovo development beyond HH34. Panels A to F are unstained, while panels G to I are stained for the alkaline phosphatase enzyme. The top row, panels A to C, shows that the eye continues to develop throughout culture, evidenced by the appearance of feather buds and the growth of the eyelids, indicated by arrows in each panel.The middle row, panels D to F, shows that the conjunctival papillae begin to degenerate in culture. The bottom row, panels G to I, shows that the spatiotemporal pattern of scleral ossicle induction is maintained in culture, serving as an example of a developmental pathway that can be studied using this method. This protocol allows tissues to maintain key spacial and temporal aspects of development throughout the entirety of culture.This protocol represents a key advancement in the culturing of whole sensory organs, providing alternative methodology for studying the intricate developmental pathways involved.

organotypic-culture-method-to-study-development-embryonic-chicken

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JoVE Journal

Developmental Biology

5.9K 次观看.  Mount Saint Vincent University. The overall goal of this protocol is to provide access to embryonic chicken eyes in an in-vitro setting to enable in-depth study of complex developmental pathways in the embryo. In the embryonic chicken, studying the eye is often difficult, due to eyelid development, embryo movement, and the growth of extra embryonic tissues. Compounds such as drugs and inhibitors can also have lethal effects on the embryo, making it difficult to use these compounds to modulate gene pathways.Advances i...