التعامل مع البيض <ol style=";text-align:right;direction:rtl"><li style=";text-align:right;direction:rtl"> يجوز إبقاء البيض على 13 درجة مئوية لمدة تصل إلى أسبوع واحد قبل الحضانة دون خسائر كبيرة في البقاء (أ برودة النبيذ الصغيرة مثالية لهذا الغرض). </li><li style=";text-align:right;direction:rtl"> قبل الحضانة ، والسماح لتدفئة البيض إلى درجة حرارة الغرفة ، ثم تضعها في ترطيب حاضنة الدجاج تعيين إلى 37.8 درجة مئوية (100 درجة فهرنهايت). </li><li style=";text-align:right;direction:rtl"> نحن electroporate الأجنة عادة حوالي 48 ساعة من بداية الحضانة ، وعندما وصلت الجنين همبرغر وهاميلتون 10 مرحلة. </li><li style=";text-align:right;direction:rtl"> قد يختلف وقت الحضانة وفقا لهمبرغر المطلوب والمرحلة هاملتون. ودرجة الحرارة الحرجة والانحراف عن درجة الحرارة المثلى تغيير الحضانة فترة حضانة وانخفاض قابلية الجنين. </li><li style=";text-align:right;direction:rtl"> أثناء الحضانة ، ينبغي أن يوضع البيض على الجانبين بحيث يكون الجنين في وضع مناسب لelectroporation. فإن الجنين تطفو على السطح من صفار وأنه من المفيد للاحتفال رأس البيضة مع قلم رصاص قبل النوافذ حتى يتسنى لك معرفة من أين قطع. </li></ol> إعداد <ol style=";text-align:right;direction:rtl"><li style=";text-align:right;direction:rtl"> الحارة يبوفيتش L - 15 وسائل الاعلام الى 37 درجة مئوية. سحب الزجاج الشعيرات الدموية في الإبر. أقطاب موقف وmicromanipulator والاتصال لأقطاب مولد النبض. </li></ol> النوافذ <ol style=";text-align:right;direction:rtl"><li style=";text-align:right;direction:rtl"> باستخدام المحاقن مع إبرة تحمل كبيرة ، تخترق قذيفة في نهاية صغيرة من البيض. </li><li style=";text-align:right;direction:rtl"> مشيرا الإبرة الهبوط بعناية لمنع الفوضى من صفار البيض ، وإزالة حول 5ml من الزلال. </li><li style=";text-align:right;direction:rtl"> ختم الحفرة مع قطعة صغيرة من الشريط. </li><li style=";text-align:right;direction:rtl"> يغطي الجزء العلوي من البيض مع آخر قطعة من الشريط (عن 4x4 سم). </li><li style=";text-align:right;direction:rtl"> باستخدام مقص منحني ، ومع الحرص على عدم تعطيل الجنين ، وقطع حفرة واسعة بما يكفي لتوفير إطار للعمل فيه. </li></ol> اختياري : لتصور الأنبوب العصبي ، وضخ الحبر الحل مع إبرة قياس 26 تحت الجنين (ادخال ابرة تحت الجنين من خارج الحلبة الدم). وينبغي أن تضعف الهند الحبر 01:05 بمحلول معقم أو هانكس مقارنة مخزنة. الحقن وElectroporation <ol style=";text-align:right;direction:rtl"><li style=";text-align:right;direction:rtl"> كسر غيض الشعرية إلى القطر المطلوب باستخدام الملقط </li><li style=";text-align:right;direction:rtl"> باستخدام ماصة الفم ، تحميل شعري مع الصبغة الخضراء البلازميد / السريع. </li><li style=";text-align:right;direction:rtl"> موقف الجنين مع رئيس نحوك وادخال الإبرة في الأنبوب العصبي بزاوية ضحلة. </li><li style=";text-align:right;direction:rtl"> حقن محلول البلازميد في تجويف الأنبوب العصبي حتى صبغ يملأ الفضاء كله. </li></ol> ملاحظة : كن حذرا ليس لديهم أكبر قطر الحافة ثم الأنبوب العصبي. عموما ، سوف تكون قادرة على معرفة ما إذا كان قد تحقق حجم الأمثل من قبل طرف مدى سهولة أو صعوبة لسحب السائل إلى الشعيرات الدموية. إذا كان هناك مقاومة حادة ، وفتح هو على الارجح صغيرة جدا ، وينبغي أن تكون مكسورة الطرف مرة أخرى على مستوى اعلى. إذا كان هناك مقاومة تذكر أو لا ، وفتح كبير جدا ويجب استخدام إبرة جديدة. <ol style=";text-align:right;direction:rtl"><li style=";text-align:right;direction:rtl"> مكان 1-2 قطرات من وسائل الاعلام L - 15 العقيمة على الجنين. </li><li style=";text-align:right;direction:rtl"> المكان فورا الأقطاب على جانبي الجنين ، موازية لالأنبوب العصبي ، ومرات في 5 نبض 10-24 فولت لمدة 50 mseconds في 1 فترات الثانية. سوف ترى فقاعات بالقرب من الأقطاب الكهربائية اذا عملت بشكل صحيح. </li><li style=";text-align:right;direction:rtl"> إزالة بعناية الأقطاب الكهربائية ، وطرح 5 قطرات من L - 15 على رأس الأجنة وختم الشريط مع البيض. تأكد من أن يتم ختم جيدا البيض ، والتجفيف هو المساهم الرئيسي في فقدان الجنين التالية electroporation. </li><li style=";text-align:right;direction:rtl"> البيض مرة أخرى إلى مكان الحاضنة ، جنبا نافذة تصل ، واحتضان حتى يصلوا المطلوب H &amp; H المرحلة. </li></ol>

<ol>
	<li>Itasaki, N., Bel-Vialar, S., Krumlauf, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=&apos;Shocking&apos;+developments+in+chick+embryology:+electroporation+and+in+ovo+gene+expression.">&apos;Shocking&apos; developments in chick embryology: electroporation and in ovo gene expression.</a> Nat Cell Biol. 1, 203-207 (1999).</li></ol>

The authors have nothing to disclose.

هذا البروتوكول يوفر دليل خطوة بخطوة لelectroporation الأنبوب العصبي للأجنة الدجاج HH10. بالإضافة إلى عرض هذه التقنية ، كما تقدم مبادئ توجيهية للتخزين والمناولة من البيض. هذه التقنية لديها مجموعة واسعة من التطبيقات للتحليل الوراثي والتكلفة المنخفضة وسهولة من التجارب يجعلها ممكنة للمخت?...

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<td>Chicken egg incubator</td>
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<td>our electrodes were made from 0.25 mm diameter platinum wire and were 5 mm long and spaced 1 mm apart</td>
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<td>10 ml syringe</td>
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<td>Large bore needle </td>
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<td>&#x2265; 1&#181;g/&#181;l in sterile TE or 1X PBS containing 0.05% Fast Green dye</td>
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in ovo electroporations of hh stage 10 chicken embryos

جعلت حجم كبير والتنمية الخارجية للجنين الدجاج طويلة يجعلها أداة قيمة في دراسة البيولوجيا التطورية. مع ظهور التقنيات البيولوجية الجزيئية ، وأصبح نظام الفرخ مفيدة للدراسة تنظيم الجينات ووظائفها. electroporating بواسطة الحمض النووي الريبي أو يبني في جنين الدجاج النامية ، يمكن التعبير عن الجينات أو ترسيتها من أجل تحليل وظائف الجينات في الجسم الحي. وبالمثل ، يمكن أن تستخدم لرسم خرائط البنى مراسل مصير أو لدراسة العناصر الجينية المفترضة التنظيمية. بالمقارنة مع تجارب مماثلة في الماوس ، وقد فرخ electroporation مزايا يجري سريعة وسهلة وغير مكلفة. هذا الفيديو يوضح أولا كيف لجعل نافذة في قشرة البيضة لمعالجة الجنين. المقبل ، والجنين هو تصور بمحلول مخفف من الحبر الهند حقن تحت الجنين. وتستخدم إبرة الزجاج وماصة لحقن الحمض النووي وصبغ الأخضر السريع في الأنبوب العصبي النامي ، ثم يتم وضع أقطاب البلاتين موازية للجنين وتدار النبضات الكهربائية قصيرة مع مولد النبض. وأخيرا ، ختم الشريط مع البيض ويوضع مرة أخرى في حاضنة لمزيد من التطوير. بالإضافة إلى ذلك ، يظهر الشريط الصحيح التخزين والمناولة والبيض يناقش الأسباب المحتملة لفقدان الجنين electroporation التالية.

Watch this Scientific Journal Video about In Ovo Electroporations of HH Stage 10 Chicken Embryos at JoVE.com

In Ovo Electroporations of HH Stage 10 Chicken Embryos

فرخ في electroporation البيضة هو الأسلوب الذي يسمح التلاعب الجيني للجنين الطيور. التطبيقات الشائعة لهذه التقنية تشمل تحليل وظيفي من الجينات وعناصر محسن المفترضة. هذا الفيديو يوضح العصبية electroporation أنبوب في الأجنة سمو الفرخ 10. وتناقش تقنية الحقن والتعامل السليم البيض.

Electroporations OVO في مرحلة الجنين سمو الدجاج 10

Large size and external development of the chicken embryo have long made it a valuable tool in the study of developmental biology.  With the advent of ...

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18.2K Views.  University of Chicago. فرخ في electroporation البيضة هو الأسلوب الذي يسمح التلاعب الجيني للجنين الطيور. التطبيقات الشائعة لهذه التقنية تشمل تحليل وظيفي من الجينات وعناصر محسن المفترضة. هذا الفيديو يوضح العصبية electroporation أنبوب في الأجنة سمو الفرخ 10. وتناقش تقنية الحقن والتعامل السليم البيض.

Video: In Ovo Electroporations of HH Stage 10 Chicken Embryos

Preparation of Neuronal Cultures from Midgastrula Stage Drosophila Embryos

This video illustrates the procedure for making primary neuronal cultures from midgastrula stage Drosophila embryos. The methods for collecting embryos and their dechorionation using bleach are demonstrated. Using a glass pipet attached to a mouth suction tube, we illustrate the removal of all cells from single embryos. The method for dispersing cells from each embyro into a small (5 l) drop of medium on an uncoated glass coverslip is demonstrated. A view through the microscope at 1 hour after plating illustrates the preferred cell density. Most of the cells that survive when grown in defined medium are neuroblasts that divide one or more times in culture before extending neuritic processes by 12-24 hours. A view through the microscope illustrates the level of neurite outgrowth and branching expected in a healthy culture at 2 days in vitro. The cultures are grown in a simple bicarbonate based defined medium, in a 5% CO2 incubator at 22-24&deg;C. Neuritic processes continue to elaborate over the first week in culture and when they make contact with neurites from neighboring cells they often form functional synaptic connections. Neurons in these cultures express voltage-gated sodium, calcium, and potassium channels and are electrically excitable. This culture system is useful for studying molecular genetic and environmental factors that regulate neuronal differentiation, excitability, and synapse formation/function.

This video demonstrates the preparation of primary neuronal cultures from midgastrula stage Drosophila embryos. Views of live cultures show cells 1 hour after plating and differentiated neurons after 2 days of growth in a bicarbonate-based defined medium. The neurons are electrically excitable and form synaptic connections.

التحضير للثقافات متعلق بالخلايا العصبية من أجنة ذبابة الفاكهة المرحلة Midgastrula

This video illustrates the procedure for making primary neuronal cultures from midgastrula stage Drosophila embryos. The methods for collecting embryos ...

Windowing Chicken Eggs for Developmental Studies

The study of development has been greatly aided by the use of the chick embryo as an experimental model.  The ease of accessibility of the embryo has allowed for experiments to map cell fates using several approaches, including chick quail chimeras and focal dye labeling.  In addition, it allows for molecular perturbations of several types, including placement of protein-coated beads and introduction of plasmid DNA using in ovo electroporation.  These experiments have yielded important data on the development of the central and peripheral nervous systems.  For many of these studies, it is necessary to open the eggshell and reclose it without perturbing the embryo's growth.  The embryo can be examined at successive developmental stages by re-opening the eggshell.  While there are several excellent methods for opening chicken eggs, in this article we demonstrate one method that has been optimized for long survival times.  In this method, the egg rests on its side and a small window is cut in the shell.  After the experimental procedure, the shell is used to cover the egg for the duration of its development.  Clear plastic tape overlying the eggshell protects the embryo and helps retain hydration during the remainder of the incubation period.  This method has been used beginning at two days of incubation and has allowed survival through mature embryonic ages.

The ease of accessibility of the embryo has allowed for experiments to map cell fates using several approaches, including chick quail chimeras and focal dye labeling. In this article we demonstrate one egg preparation method that has been optimized for long survival times.

بيض الدجاج النوافذ للدراسات الإنمائية

The study of development has been greatly aided by the use of the chick embryo as an experimental model.  The ease of accessibility of the embryo has ...

Placing Growth Factor-Coated Beads on Early Stage Chicken Embryos

The neural tube expresses many proteins in specific spatiotemporal patterns during development. These proteins have been shown to be critical for cell fate determination, cell migration, and formation of neural circuits. Neuronal induction and patterning involve bone morphogenetic protein (BMP), sonic hedgehog (SHH), fibroblast growth factor (FGF), among others. In particular, the expression pattern of Fgf8 is in close proximity to regions expressing BMP4 and SHH. This expression pattern is consistent with developmental interactions that facilitate patterning in the telencephalon.

Here we provide a visual demonstration of a method in which an in ovo preparation can be used to test the effects of Fgfs in the formation of the forebrain. Beads are coated with protein and placed in the developing neural tube to provide sustained exposure. Because the procedure uses small, carefully placed beads, it is minimally invasive and allows several beads to be placed within a single neural tube. Moreover, the method allows for continued development so that embryos can be analyzed at a more mature stage to detect changes in anatomy and in neural patterning. This simple but useful protocol allows for real time imaging. It provides a means to make spatially and temporally limited changes to endogenous protein levels.

A variety of growth factors and proteins interact to induce cells to take on different cell fates during development. Here we demonstrate the use of an in ovo preparation to address possible interactions between different proteins in development by placing beads on E2.5 chick embryos.

وضع عامل النمو المغلفه الخرز على أجنة الدجاج المرحلة المبكرة

The neural tube expresses many proteins in specific spatiotemporal patterns during development.   These proteins have been shown to be critical for cell ...

Chick ex ovo Culture and ex ovo CAM Assay: How it Really Works

Chicken eggs in the early phase of breeding are between in vitro and in vivo systems and provide a vascular test environment not only to study angiogenesis but also to study tumorigenesis. After the chick chorioallantoic membrane (CAM) has developed, its blood vessel network can be easily accessed, manipulated and observed and therefore provides an optimal setting for angiogenesis assays. Since the lymphoid system is not fully developed until late stages of incubation, the chick embryo serves as a naturally immunodeficient host capable of sustaining grafted tissues and cells without species-specific restrictions. In addition to nurturing developing allo- and xenografts, the CAM blood vessel network provides a uniquely supportive environment for tumor cell intravasation, dissemination, and vascular arrest and a repository where arrested cells extravasate to form micro metastatic foci.
For experimental purposes, in most of the recent studies the CAM was exposed by cutting a window through the egg shell and experiments were carried out in ovo, resulting in significant limitations in the accessibility of the CAM and possibilities for observation and photo documentation of effects. When shell-less cultures of the chick embryo were used1-4, no experimental details were provided and, if published at all, the survival rates of these cultures were low. We refined the method of ex ovo culture of chick embryos significantly by introducing a rationally controlled extrusion of the egg content. These ex ovo cultures enhance the accessibility of the CAM and chick embryo, enabling easy in vivo documentation of effects and facilitating experimental manipulation of the embryo. This allows the successful application to a large number of scientific questions: (1) As an improved angiogenesis assay5,6, (2) an experimental set up for facilitated injections in the vitreous of the chick embryo eye7-9, (3) as a test environment for dissemination and intravasation of dispersed tumor cells from established cell lines inoculated on the CAM10-12, (4) as an improved sustaining system for successful transplantation and culture of limb buds of chicken and mice13 as well as (5) for grafting, propagation, and re-grafting of solid primary tumor tissue obtained from biopsies on the surface of the CAM14.
In this video article we describe the establishment of a refined chick ex ovo culture and CAM assay with survival rates over 50%. Besides we provide a step by step demonstration of the successful application of the ex ovo culture for a large number of scientific applications. 
Daniel S. Dohle, Susanne D. Pasa, and Sebastian Gustmann contributed equally to this study.

Chick ex ovo Culture and ex ovo CAM Assay: How it Really Works

The chick chorioallantoic membrane (CAM) is a unique, naturally immunodeficient supportive culture environment to study angiogenesis and tumorigenesis. This video article demonstrates the different steps in chick ex ovo culture, application of potentially angiogenic substances and successful inoculation of tumor cells and tissues on the surface of the CAM.

كتكوت البيضة السابقين الثقافة و البيضة السابقين CAM الفحص : كيف يعمل حقا

Chicken eggs in the early phase of breeding are between in vitro and in vivo systems and provide a vascular test environment not only to study ...

In-vivo Centrifugation of Drosophila Embryos

A major strategy for purifying and isolating different types of intracellular organelles is to separate them from each other based on differences in buoyant density. However, when cells are disrupted prior to centrifugation, proteins and organelles in this non-native environment often inappropriately stick to each other. Here we describe a method to separate organelles by density in intact, living Drosophila embryos. Early embryos before cellularization are harvested from population cages, and their outer egg shells are removed by treatment with 50% bleach. Embryos are then transferred to a small agar plate and inserted, posterior end first, into small vertical holes in the agar. The plates containing embedded embryos are centrifuged for 30 min at 3000g. The agar supports the embryos and keeps them in a defined orientation. Afterwards, the embryos are dug out of the agar with a blunt needle. Centrifugation separates major organelles into distinct layers, a stratification easily visible by bright-field microscopy. A number of fluorescent markers are available to confirm successful stratification in living embryos. Proteins associated with certain organelles will be enriched in a particular layer, demonstrating colocalization. Individual layers can be recovered for biochemical analysis or transplantation into donor eggs. This technique is applicable for organelle separation in other large cells, including the eggs and oocytes of diverse species.

In-vivo Centrifugation of Drosophila Embryos

We describe a method to separate organelles by density in living Drosophila embryos. Embryos are embedded in agar and centrifuged. This technique yields reproducible separation of major organelles along the anterior-posterior embryo axis. This method facilitates colocalization experiments and yields organelle fractions for biochemical analysis and transplantation experiments.

داخل الجسم الحي الطرد المركزي الجنين ذبابة الفاكهة

A major strategy for purifying and isolating different types of intracellular organelles is to separate them from each other based on differences in ...

An ex-ovo Chicken Embryo Culture System Suitable for Imaging and Microsurgery Applications

Understanding the relationships between genetic and microenvironmental factors that drive normal and malformed embryonic development is fundamental for discovering new therapeutic strategies. Advancements in imaging technology have enabled quantitative investigation of the organization and maturing of the body plan, but later stage embryonic morphogenesis is less clear. Chicken embryos are an attractive vertebrate animal model system for this application because of its ease of culture and surgical manipulation. Early embryos can be cultured for a short time on filter paper rings, which enables complete optical access for cell patterning and fate studies1,2. Studying advanced developmental processes such as cardiac morphogenesis are traditionally performed through a window of the eggshell3-5, but this technique limits optical access due to window size. We previously developed a simple method to culture whole embryos ex-ovo on hexagonal weigh boats for up to 10 days, which enabled high resolution imaging via ultrasonography6,7. These cultures were difficult to transport, limiting the types of imaging tools available for live experiments. We here present an improved shell-less culture system with a cost-effective, portable environmental chamber. Eggs were cracked onto a hammock created by a polyurethane membrane (cling wrap) affixed circumferentially to a plastic cup partially filled with sterile water. The dimensions of the circumference and depth of the hammock were both critical to maintain surface tension, while the mechanics of the hammock and water beneath helped dampen vibrations induced by transportation. A small footprint circulating water bath was also developed to enable continuous temperature control during experimentation. We demonstrate the ability to culture embryos in this way for at least 14 days without morphogenic defect or delay and employ this system in several microsurgical and imaging applications.

An ex-ovo Chicken Embryo Culture System Suitable for Imaging and Microsurgery Applications

In this article, we present a simple methodology to enable long-term ex-ovo avian embryo culture. This technique is ideal for longitudinal experimentation requiring complete optical accessibility and/or sterile transportation in avian embryos.

و السابقين البيضة الثقافة الأجنة النظام الدجاج مناسبة للتطبيقات التصوير والجراحة المجهرية

Understanding the relationships between genetic and microenvironmental factors that drive normal and malformed embryonic development is fundamental for ...

Imaging Cell Shape Change in Living Drosophila Embryos

The developing Drosophila melanogaster embryo undergoes a number of cell shape changes that are highly amenable to live confocal imaging. Cell shape changes in the fly are analogous to those in higher organisms, and they drive tissue morphogenesis. So, in many cases, their study has direct implications for understanding human disease (Table 1)1-5. On the sub-cellular scale, these cell shape changes are the product of activities ranging from gene expression to signal transduction, cell polarity, cytoskeletal remodeling and membrane trafficking. Thus, the Drosophila embryo provides not only the context to evaluate cell shape changes as they relate to tissue morphogenesis, but also offers a completely physiological environment to study the sub-cellular activities that shape cells.
The protocol described here is designed to image a specific cell shape change called cellularization. Cellularization is a process of dramatic plasma membrane growth, and it ultimately converts the syncytial embryo into the cellular blastoderm. That is, at interphase of mitotic cycle 14, the plasma membrane simultaneously invaginates around each of ~6000 cortically anchored nuclei to generate a sheet of primary epithelial cells. Counter to previous suggestions, cellularization is not driven by Myosin-2 contractility6, but is instead fueled largely by exocytosis of membrane from internal stores7. Thus, cellularization is an excellent system for studying membrane trafficking during cell shape changes that require plasma membrane invagination or expansion, such as cytokinesis or transverse-tubule (T-tubule) morphogenesis in muscle.
Note that this protocol is easily applied to the imaging of other cell shape changes in the fly embryo, and only requires slight adaptations such as changing the stage of embryo collection, or using "embryo glue" to mount the embryo in a specific orientation (Table 1)8-19. In all cases, the workflow is basically the same (Figure 1). Standard methods for cloning and Drosophila transgenesis are used to prepare stable fly stocks that express a protein of interest, fused to Green Fluorescent Protein (GFP) or its variants, and these flies provide a renewable source of embryos. Alternatively, fluorescent proteins/probes are directly introduced into fly embryos via straightforward micro-injection techniques9-10. Then, depending on the developmental event and cell shape change to be imaged, embryos are collected and staged by morphology on a dissecting microscope, and finally positioned and mounted for time-lapse imaging on a confocal microscope.

Imaging Cell Shape Change in Living Drosophila Embryos

Early development of the fruit fly, Drosophila melanogaster, is characterized by a number of cell shape changes that are well suited for imaging approaches. This article will describe basic tools and methods required for live confocal imaging of Drosophila embryos, and will focus on a cell shape change called cellularization.

التصوير تغيير الشكل في الخلية الحية ذبابة الفاكهة الأجنة

The developing Drosophila melanogaster embryo undergoes a number of cell shape changes that are highly amenable to live confocal imaging.  Cell shape ...

Chromatin Immunoprecipitation Assay for Tissue-specific Genes using Early-stage Mouse Embryos

Chromatin immunoprecipitation (ChIP) is a powerful tool to identify protein:chromatin interactions that occur in the context of living cells 1-3. This technique has been widely exploited in tissue culture cells, and to a lesser extent, in primary tissue. The application of ChIP to rodent embryonic tissue, especially at early times of development, is complicated by the limited amount of tissue and the heterogeneity of cell and tissue types in the embryo. Here we present a method to perform ChIP using a dissociated embryonic day 8.5 (E8.5) embryo. Sheared chromatin from a single E8.5 embryo can be divided into up to five aliquots, which allows the investigator sufficient material for controls and for investigation of specific protein:chromatin interactions.
We have utilized this technique to begin to document protein:chromatin interactions during the specification of tissue-specific gene expression programs. The heterogeneity of cell types in an embryo necessarily restricts the application of this technique because the result is the detection of protein:chromatin interactions without distinguishing whether the interactions occur in all, a subset of, or a single cell type(s). However, examination of tissue-specific genes during or following the onset of tissue-specific gene expression is feasible for two reasons. First, immunoprecipitation of tissue specific factors necessarily isolates chromatin from the cell type where the factor is expressed. Second, immunoprecipitation of coactivators and histones containing post-translational modifications that are associated with gene activation should only be found at genes and gene regulatory sequences in the cell type where the gene is being or has been activated. The technique should be applicable to the study of most tissue-specific gene activation events.
In the example described below, we utilized E8.5 and E9.5 mouse embryos to examine factor binding at a skeletal muscle specific gene promoter. Somites, which are the precursor tissues from which the skeletal muscles of the trunk and limbs will form, are present at E8.5-9.54,5. Myogenin is a regulatory factor required for skeletal muscle differentiation 6-9. The data demonstrate that myogenin is associated with its own promoter in E8.5 and E9.5 embryos. Because myogenin is only expressed in somites at this stage of development 6,10, the data indicate that myogenin interactions with its own promoter have already occurred in skeletal muscle precursor cells in E8.5 embryos.

We demonstrate a chromatin immunoprecipitation (ChIP) method to identify factor interactions at tissue-specific genes during or after the onset of tissue-specific gene expression in mouse embryonic tissue. This protocol should be widely applicable for the study of tissue-specific gene activation as it occurs during normal embryonic development.

مناعي لونين الفحص الجينات الأنسجة الخاصة باستخدام أجنة فئران في مرحلة مبكرة

Chromatin immunoprecipitation (ChIP) is a powerful tool to identify protein:chromatin interactions that occur in the context of living cells 1-3. This ...

In Ovo Electroporation in Embryonic Chick Retina

Chicken embryonic retina is an excellent tool to study retinal development in higher vertebrates. Because of large size and external development, it is comparatively very easy to manipulate the chick embryonic retina using recombinant DNA/RNA technology. Electroporation of DNA/RNA constructs into the embryonic retina have a great advantage to study gene regulation in retinal stem/progenitor cells during retinal development. Different type of assays such as reporter gene assay, gene over-expression, gene knock down (shRNA) etc. can be performed using the electroporation technique. This video demonstrates targeted retinal injection and in ovo electroporation into the embryonic chick retina at the Hamburger and Hamilton stage 22-23, which is about embryonic day 4 (E4). Here we show a rapid and convenient in ovo electroporation technique whereby a plasmid DNA that expresses green fluorescent protein (GFP) as a marker is directly delivered into the chick embryonic subretinal space and followed by electric pulses to facilitate DNA uptake by retinal stem/progenitor cells. The new method of retinal injection and electroporation at E4 allows the visualization of all retinal cell types, including the late-born neurons1, which has been difficult with the conventional method of injection and electroporation at E1.52.

In Ovo Electroporation in Embryonic Chick Retina

The overall goal of this video is to show how to perform targeted retinal injection and in ovo electroporation of DNA/RNA constructs into the chick embryonic retina at the Hamburger and Hamilton stage 22-23, which is about embryonic day 4 (E4). This technique is very useful to study gene expression, gene regulation, and morphological change in developing chick retina.

في Electroporation OVO في شبكية العين الفرخ الجنينية

Chicken embryonic retina is an excellent tool to study retinal development in higher vertebrates. Because of large size and external development, it is ...

Gene Transfer into Older Chicken Embryos by ex ovo Electroporation

The chicken embryo provides an excellent model system for studying gene function and regulation during embryonic development. In ovo electroporation is a powerful method to over-express exogenous genes or down-regulate endogenous genes in vivo in chicken embryos1. Different structures such as DNA plasmids encoding genes2-4, small interfering RNA (siRNA) plasmids5, small synthetic RNA oligos6, and morpholino antisense oligonucleotides7 can be easily transfected into chicken embryos by electroporation. However, the application of in ovo electroporation is limited to embryos at early incubation stages (younger than stage HH20 - according to Hamburg and Hamilton)8 and there are some disadvantages for its application in embryos at later stages (older than stage HH22 - approximately 3.5 days of development). For example, the vitelline membrane at later stages is usually stuck to the shall membrane and opening a window in the shell causes rupture of the vessels, resulting in death of the embryos; older embryos are covered by vitelline and allantoic vessels, where it is difficult to access and manipulate the embryos; older embryos move vigorously and is difficult to control the orientation through a relatively small window in the shell.
In this protocol we demonstrate an ex ovo electroporation method for gene transfer into chicken embryos at late stages (older than stage HH22). For ex ovo electroporation, embryos are cultured in Petri dishes9 and the vitelline and allantoic vessels are widely spread. Under these conditions, the older chicken embryos are easily accessed and manipulated. Therefore, this method overcomes the disadvantages of in ovo electroporation applied to the older chicken embryos. Using this method, plasmids can be easily transfected into different parts of the older chicken embryos10-12.

Gene Transfer into Older Chicken Embryos by ex ovo Electroporation

A method of gene transfer into chicken embryos at later incubation stages (older than Hamburger and Hamilton stage (HH) 22) is described. This method overcomes disadvantages of in ovo electroporation applied to older chicken embryos and is a useful technique to study gene function and regulation at older developmental stages.

نقل الجينات في أجنة الدجاج أقدم من قبل<em&gt; OVO السابقين</em&gt; Electroporation

The chicken embryo provides an  excellent model system for studying gene function and regulation during  embryonic development. In ovo electroporation is ...