知识产权由加拿大自然科学与工程研究理事会资助（NSERC＃418233-2012）资助;魁北克省魁北克省圣诞老人（FRQS），魁北克省乳腺癌基金会职业生涯奖，以及加拿大创新基金会授予的领导者资助。 ED获得了Fondation大学生Armand-Frappier奖学金。

本研究中使用的所有动物方案均由大学动物护理委员会（INRS-Institut Armand-Frappier，Laval，Canada）批准。 识别蛋白质共定位<ol><li> 从组织到显微镜片 注意:组织和部分应在干冰上处理。 <ol><li>从动物上清除乳腺（有关此程序的完整描述，请参阅Plante 等人 ）。 </li><li>将切除的组织嵌入冷冻/安装介质中的干冰上。添加足够的培养基覆盖腺体。当培养基固化时，将组织转移到-80℃的冷冻箱中供以后使用9 。 </li><li>使用设置在-35°C的冷冻切片机，将组织切成7-10μm厚的切片并将其放置在显微镜载玻片上。 注意:尽可能在每张幻灯片上放置两个部分;左侧部分将被用作特异性对照以验证抗体的特异性和组织的自发荧光，而右侧将用抗体标记。 </li><li>将部分保持在-80°C以备后用。 </li></ol></li><li> Co-IF染色 <ol><li>从冷冻箱中取出适当的微观载玻片，并在室温（RT）下将其浸入4％甲醛中15分钟立即固定切片。 </li><li>然后在室温下将载玻片浸入磷酸盐缓冲盐水（PBS）中。将幻灯片放在PBS中，直到进入下一步。 </li><li>使用市售的疏水屏障或防水实验笔（参见"材料表" ）圈住滑块的每个部分。小心不要接触组织。立即向组织中加入一滴PBS，并将载玻片置于潮湿的组织学室中，以进行剩余的操作。 注意:组织切片必须保持保湿。替代请使用带盖的盒子，并将湿纸巾放在底部。 </li><li>使用100-200μL3％牛血清白蛋白（BSA）-Tris缓冲盐水（TBS）-0.1％聚山梨醇酯20（参见材料表 ）将每个组织切片封闭 30分钟。当样品阻塞时，通过在TBS-0.1％聚山梨醇酯20中稀释抗体来制备一抗和二次抗体溶液。 注意:抗体所需的浓度由制造商提供;参见材料表和图1和图2 ，以及Dianati 等人 9 。尽管在使用大多数荧光团缀合的抗体时不需要在黑暗中工作，但避免将抗体溶液或染色的组织暴露于强烈的明亮的光线下。 </li><li>通过抽吸去除封闭溶液，并在室温下将100-200μL稀释的一抗孵育切片60分钟。 Alternatively，在4℃下与第一抗体孵育过夜。 </li><li>通过抽吸去除一级抗体溶液，并用250-500μLTBS-0.1％聚山梨醇酯20洗涤切片5分钟。通过抽吸去除洗涤液，重复洗涤两次。 </li><li>通过抽吸去除洗涤溶液，并在室温下用100-200μL适当的荧光团缀合的二抗孵育切片60分钟。 </li><li>通过抽吸去除第二抗体溶液，并用250-500μLTBS-0.1％聚山梨醇酯20洗涤切片5分钟。取出洗液并重复两次。 </li><li>重复步骤2.5-2.8，使用适当的初级和次级抗体组合，用于感兴趣的后续蛋白质。 </li><li>通过抽吸去除洗涤溶液并通过将部分与100-200μL的1mg / mL 4&#39;，6-二脒基-2-苯基吲哚（DAPI）在TBS-0.1％聚山梨醇酯20中孵育5分钟进行核染色，并进行细胞核染色RT。 </li><li>通过抽吸去除DAPI溶液，并使用水溶性，非荧光的安装介质（参见材料表 ）和盖玻片安装载玻片。一次进行一张幻灯片。 注意:孵育核染色超过5分钟不会改变染色强度。或者，移除所有载玻片上的DAPI溶液，并在安装载玻片的同时孵育PBS中的组织。 </li><li>将幻灯片平放在4°C冰箱中至少8小时。继续进行荧光显微镜成像（参见图1和图2 ）。 </li></ol></li><li> 显微成像 <ol><li>使用配备有在其特定波长处激发荧光团所需的各种激光器的共聚焦显微镜来观察荧光团缀合的二次抗体。 注意:为了能够可视化管道和肺泡，建议使用数值孔径为0.95的40X物镜。例如e的具体设置如图1所示 。 </li><li>通过在当时扫描一幅波长的图像来单独验证每种蛋白质的定位。 注意:在这个阶段，重要的是严格分析连接蛋白的定位。为了能够形成连接核酸，这些蛋白质必须位于质膜上。 </li><li>通过合并在不同波长的激光扫描的图像来确定蛋白质的共定位。 注意:蛋白质共定位可以通过在相同位置发射两个或更多个荧光团而产生的颜色变化来显现，并且可以使用适当的软件测量（ 图1和2 ;也参见参考文献9）。 </li></ol></li></ol> 2.学习PPI 注意:腹部乳腺应用于研究PPI，因为胸腺与胸部紧密相关肌肉。消毒乳腺（有关此程序的完整说明，请参阅Plante 等人 ） 14并将其保持在-80°C以备后用。 <ol><li> 裂解液制备 <ol><li>将称重纸和2 mL微量离心管放在干冰上预先冷却，然后再进行下一步骤。 </li><li>从-80°C取乳腺组织，并将其保存在干冰上。 </li><li>称重预冷计量纸上的组织，然后将组织转移到2 mL微量离心管（干冰处理）上。每个样品使用50至100 mg的组织。将组织保持在干冰上，直到步骤2.1.5。 </li><li>使用下列公式，制备所需量的补充有NaF，NaVO 3和蛋白酶/磷酸酶抑制剂的三重洗涤剂溶解缓冲液，如材料表所示。小鼠:所需缓冲液（μL）=小鼠组织重量（mg）×3;老鼠:需要缓冲液（μL）=大鼠组织重量（mg）×5。 </li><li>将所需量的冰冷裂解缓冲液（在步骤2.1.4中计算）加入到含有组织的2mL管中。 注意:在步骤2.1.5-2.1.6中，一次进行一根单管。 </li><li>使用组织研磨机上的连续匀浆将组织匀化30-40秒;始终将管保持在冰上。将组织匀浆器调整至中等速度，并轻轻地将研磨机上下移动到管内。 </li><li>与其他管重复步骤1.6和1.7。 </li><li>将溶胞产物在冰上孵育10-30分钟。 </li><li>在4℃下以170×g离心管10分钟。 </li><li>同时，为每个样品确定6-10个微量离心管（0.6 mL），并将其保存在冰上。 </li><li>离心完成后，检查管子。确保它们含有顶层脂肪，透明，黄色至粉红色的裂解物（取决于显影阶段）和颗粒。 </li><li>在脂质层中创建一个孔使用200μL移液管吸头进入液相。改变提示并收集裂解物，而不会干扰沉淀或吸入脂质层。将裂解物在冰上预先标记的管中等分（步骤2.1.11），并将其储存在-80℃。 </li><li>使用等分试样使用适当的市售试剂盒来定量蛋白质浓度（见材料表 ）。 </li></ol></li><li> 间接免疫沉淀 <ol><li>在冰上，解冻之前制备的全部乳腺裂解物的两个等分试样。 注意:一个等分试样将用于目标蛋白质的IP，而另一个将用作阴性对照。 </li><li>收集500-1,000μg裂解物，并在PBS中稀释至每个1.5 mL管中达到最终体积200μL。 注意:使用的裂解物的量取决于感兴趣的蛋白质的丰度和抗体的效率（参见图3的例如，以及材料表 ）。为了优化每个靶，应使用不同量的裂解物（ 即 500,750和1,000μg）和抗体（ 即 5,10和20μg）。继续执行以下步骤（2.2.3-2.3.7.4）。 </li><li>将针对感兴趣的抗原的抗体添加到第一个裂解物管中并保持在冰上。 注意:所需金额通常由每家公司提供的说明书中提出（见材料表 ）。 </li><li>在第二管中，通过加入与步骤2.2.3中使用的抗体相同的同种型IgG对照浓度来制备阴性对照。 </li><li>在管式辊式混合器中以4℃低速孵育管过夜。 </li><li>第二天，将50μL磁珠加入新的1.5 mL管中进行预洗。 <ol><li>基于对抗体的相对亲和力，选择蛋白A或蛋白G磁珠。 </l我&gt; <li>避免使用聚集的珠子是很重要的;轻轻混合珠悬浮液，直至将其均匀地重新悬浮，然后再加入管中。 </li></ol></li><li>将含有珠粒的管放在磁性支架上，使珠子迁移到磁体上。使用200μL移液管从珠中取出储存缓冲液。 </li><li>通过加入500μLPBS-0.1％聚山梨醇酯20洗涤珠子，并将管子剧烈旋转10秒。 </li><li>将管子放回到磁性支架上，让珠子移动到磁铁上。 </li><li>用200μL移液管移液多余的洗涤缓冲液。 </li><li>将步骤2.2.5中的反应络合物（裂解物抗体）加入到珠中，并在辊式混合器中在室温下孵育90分钟。 </li><li>将管放在磁性支架上，使珠子迁移到磁铁上。使用200μL移液管，吸出并丢弃裂解物，并将管置于冰上。 </li><li>清洗珠子通过加入500μLPBS，将管置于磁性架上，并用200μL移液管除去液体。重复这个洗涤步骤。在洗涤步骤中，避免涡旋并将样品保持在冰上。 </li><li>用PBS-0.1％聚山梨醇酯20洗涤珠子一次，不涡旋，并使用200μL移液管吸头丢弃最后的洗涤缓冲液。 </li><li>为了洗脱，向管中加入20μL的0.2M酸性甘氨酸（pH = 2.5），并在辊式混合机上摇动7分钟。 </li><li>以高速离心几秒钟（快速旋转），并将上清液收集在新鲜的冰冷管中。 </li><li>对每个管重复步骤2.2.14和2.2.15。 注意:最终体积为40μL。 </li><li>将10μL4x Laemmli缓冲液加入到步骤2.2.16的40μL洗脱样品中。 注意:由于酸性pH，颜色会变黄。 </li><li>立即将1 M Tris（pH = 8）一次一滴加入从步骤2.2.18洗脱的样品至其颜色变蓝继续下一个管。 </li><li>将样品从步骤2.2.18在70-90℃下煮沸10分钟。立即进行凝胶电泳。或者，将样品转移至-80°C的冷冻箱中直至加载。 </li></ol></li><li> 下游应用:凝胶电泳，然后进行Western印迹 <ol><li>按照标准程序准备分离和堆叠SDS-PAGE丙烯酰胺凝胶（1.5 mm厚） 15 。 注意:凝胶的选择（8-15％丙烯酰胺，梯度:参见材料表 ）应根据要沉淀的蛋白质的分子大小和待分析的潜在的结合配偶体来确定。这些蛋白质必须彼此分离，以便进行适当的免疫检测。 </li><li>在冰上解冻免疫沉淀（IP） - 样品（步骤2.2.20）。 </li><li>从相同的样品制备蛋白质裂解物（用于上述IP程序）。使用50的总裂解物并加入4X Laemmli样品缓冲液。将样品在70-90℃下煮沸5分钟，置于冰上直至加载。 注意:这些样品将在洗脱的IP样品旁边加载，以证明在总裂解物中存在沉淀的蛋白质。 </li><li>将来自步骤2.3.3的制备的裂解物和来自步骤2.2.20的沉淀的样品并排放在丙烯酰胺凝胶中，并将其运行在运行缓冲液（10×运行缓冲液:30.3g Tris，144.1g甘氨酸和10在1L蒸馏水中的SDS）在100V下进行近似95分钟，或者直到迁移蛋白的边缘到达凝胶的底部。 </li><li>使用标准方案9,15将凝胶转移到硝酸纤维素或PVDF膜上。 </li><li>在5％干牛奶-TBSBS（20mM Tris，500mM NaCl，和0.05％聚山梨醇酯20）中，在低速摇瓶上将膜封闭1小时。 </li><li>确定降水是否成功cessful。 <ol><li>探测使用针对沉淀蛋白的第一抗体的膜，以5％干奶牛TTBS以制造商推荐的浓度稀释，在4℃下在缓慢搅动的摇摆平台上过夜。 注:有关建议，请参见材料表 。 </li><li>第二天，用高速搅拌的摇摆平台上的TTBS洗涤膜3次，每次5分钟。 </li><li>在慢慢搅拌的摇摆平台上，将RTT上缀合有辣根过氧化物酶（HRP）的适当的二抗体在TTBS上孵育1小时。 注意:或者，如果检测到信号的适当装置可用，则可以使用与荧光染料缀合的二抗。 </li><li>在高搅拌的摇摆平台上进行3至6次洗涤，每次5分钟，用TTBS洗涤。通过将膜与商业化孵育来分析二抗的信号可用的鲁米诺溶液（见材料表 ），并遵循制造商说明。使用化学发光成像系统检测信号（参见材料表 ）。 注意:有关Western印迹分析的详细方案，请参见参考文献16。 </li></ol></li><li>要确定相互作用的蛋白质，请执行步骤2.3.7.1-2.3.7.4在相同印迹上使用适当的抗体。 注意:如果蛋白质相互作用，结合配偶体将与靶蛋白共同免疫沉淀，因此可通过Western印迹法检测。可以用更多的抗体重复步骤2.3.8，以确定其他蛋白质是否存在于相同的蛋白质复合物中，只要蛋白质的分子量不同就足以在凝胶和膜上分离得很好。 </li><li>要确认所识别的绑定伙伴不是工件，应执行互惠IP。 注意:这是通过重复执行的步骤2.2.1-2.2.20，其具有相同的裂解物，但沉淀步骤3.8中鉴定的结合伴侣之一。然后，使用针对目的蛋白的第一抗体重复步骤3.1-3.8。 </li></ol></li></ol>

<ol>
	<li>Sternlicht, M. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Key+stages+in+mammary+gland+development:+the+cues+that+regulate+ductal+branching+morphogenesis.">Key stages in mammary gland development: the cues that regulate ductal branching morphogenesis.</a> Breast Cancer Res. 8 (1), 201 (2006).</li><li>Oakes, S. R., Hilton, H. N., Ormandy, C. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+alveolar+switch:+coordinating+the+proliferative+cues+and+cell+fate+decisions+that+drive+the+formation+of+lobuloalveoli+from+ductal+epithelium.">The alveolar switch: coordinating the proliferative cues and cell fate decisions that drive the formation of lobuloalveoli from ductal epithelium.</a> Breast Cancer Res. 8 (2), 207 (2006).</li><li>Stein, T., Hilton, H. N., Ormandy, C. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+alveolar+switch:+coordinating+the+proliferative+cues+and+cell+fate+decisions+that+drive+the+formation+of+lobuloalveoli+from+ductal+epithelium.">The alveolar switch: coordinating the proliferative cues and cell fate decisions that drive the formation of lobuloalveoli from ductal epithelium.</a> Breast Cancer Res. 8 (2), 207 (2006).</li><li>El-Sabban, M. E., Abi-Mosleh, L. F., Talhouk, R. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Developmental+regulation+of+gap+junctions+and+their+role+in+mammary+epithelial+cell+differentiation.">Developmental regulation of gap junctions and their role in mammary epithelial cell differentiation.</a> J Mammary Gland Biol Neoplasia. 8 (4), 463-473 (2003).</li><li>Hennighausen, L., Robinson, G. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Information+networks+in+the+mammary+gland.">Information networks in the mammary gland.</a> Nat Rev Mol Cell Biol. 6 (9), 715-725 (2005).</li><li>Gudjonsson, T., Adriance, M. C., Sternlicht, M. D., Petersen, O. W., Bissell, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Myoepithelial+cells:+their+origin+and+function+in+breast+morphogenesis+and+neoplasia.">Myoepithelial cells: their origin and function in breast morphogenesis and neoplasia.</a> J Mammary Gland Biol Neoplasia. 10 (3), 261-272 (2005).</li><li>Nguyen, D. A., Neville, M. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tight+junction+regulation+in+the+mammary+gland.">Tight junction regulation in the mammary gland.</a> J Mammary Gland Biol Neoplasia. 3 (3), 233-246 (1998).</li><li>Stewart, M. K., Simek, J., Laird, D. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Insights+into+the+role+of+connexins+in+mammary+gland+morphogenesis+and+function.">Insights into the role of connexins in mammary gland morphogenesis and function.</a> Reproduction. 149 (6), R279-R290 (2015).</li><li>Dianati, E., Poiraud, J., Weber-Ouellette, A., Connexins Plante, I., E-cadherin, <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Claudin-7+and+beta-catenin+transiently+form+junctional+nexuses+during+the+post-natal+mammary+gland+development.">Claudin-7 and beta-catenin transiently form junctional nexuses during the post-natal mammary gland development.</a> Dev Biol. 416 (1), 52-68 (2016).</li><li>Derangeon, M., Spray, D. C., Bourmeyster, N., Sarrouilhe, D., Herve, 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=Reciprocal+influence+of+connexins+and+apical+junction+proteins+on+their+expressions+and+functions.">Reciprocal influence of connexins and apical junction proteins on their expressions and functions.</a> Biochim Biophys Acta. 1788 (4), 768-778 (2009).</li><li>Hernandez-Blazquez, F. J., Joazeiro, P. P., Omori, Y., Yamasaki, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Control+of+intracellular+movement+of+connexins+by+E-cadherin+in+murine+skin+papilloma+cells.">Control of intracellular movement of connexins by E-cadherin in murine skin papilloma cells.</a> Exp Cell Res. 270 (2), 235-247 (2001).</li><li>Kiyokawa, E., Hara, S., Nakamura, T., Matsuda, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fluorescence+(Forster)+resonance+energy+transfer+imaging+of+oncogene+activity+in+living+cells.">Fluorescence (Forster) resonance energy transfer imaging of oncogene activity in living cells.</a> Cancer Sci. 97 (1), 8-15 (2006).</li><li>Gustafsdottir, S. 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=Proximity+ligation+assays+for+sensitive+and+specific+protein+analyses.">Proximity ligation assays for sensitive and specific protein analyses.</a> Anal Biochem. 345 (1), 2-9 (2005).</li><li>Plante, I., Stewart, M. K., Laird, D. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluation+of+mammary+gland+development+and+function+in+mouse+models.">Evaluation of mammary gland development and function in mouse models.</a> J Vis Exp. (53), (2011).</li><li>Green, M. R., Sambrook, J., Sambrook, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Molecular cloning: a laboratory manual. , (2012).</li><li>Taylor, S. C., Berkelman, T., Yadav, G., Hammond, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+defined+methodology+for+reliable+quantification+of+Western+blot+data.">A defined methodology for reliable quantification of Western blot data.</a> Mol Biotechnol. 55 (3), 217-226 (2013).</li><li>Oxford, E. 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=Molecular+composition+of+the+intercalated+disc+in+a+spontaneous+canine+animal+model+of+arrhythmogenic+right+ventricular+dysplasia/cardiomyopathy.">Molecular composition of the intercalated disc in a spontaneous canine animal model of arrhythmogenic right ventricular dysplasia/cardiomyopathy.</a> Heart Rhythm. 4 (9), 1196-1205 (2007).</li><li>Wang, X., Li, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Protein+mislocalization:+mechanisms,+functions+and+clinical+applications+in+cancer.">Protein mislocalization: mechanisms, functions and clinical applications in cancer.</a> Biochim Biophys Acta. 1846 (1), 13-25 (2014).</li><li>Bertocchi, C., 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=Nanoscale+architecture+of+cadherin-based+cell+adhesions.">Nanoscale architecture of cadherin-based cell adhesions.</a> Nat Cell Biol. 19 (1), 28-37 (2017).</li><li>Bajar, B. T., Wang, E. S., Zhang, S., Lin, M. Z., Chu, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Guide+to+Fluorescent+Protein+FRET+Pairs.">A Guide to Fluorescent Protein FRET Pairs.</a> Sensors (Basel). 16 (9), (2016).</li><li>Fredriksson, K., 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=Proteomic+analysis+of+proteins+surrounding+occludin+and+claudin-4+reveals+their+proximity+to+signaling+and+trafficking+networks.">Proteomic analysis of proteins surrounding occludin and claudin-4 reveals their proximity to signaling and trafficking networks.</a> PLoS One. 10 (3), e0117074 (2015).</li><li>Weibrecht, I., 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=Proximity+ligation+assays:+a+recent+addition+to+the+proteomics+toolbox.">Proximity ligation assays: a recent addition to the proteomics toolbox.</a> Expert Rev Proteomics. 7 (3), 401-409 (2010).</li><li>Malovannaya, 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=Streamlined+analysis+schema+for+high-throughput+identification+of+endogenous+protein+complexes.">Streamlined analysis schema for high-throughput identification of endogenous protein complexes.</a> Proc Natl Acad Sci U S A. 107 (6), 2431-2436 (2010).</li></ol>

作者没有任何声明。

通过连接的细胞 - 细胞相互作用是许多器官（如乳腺）的正常功能和发育所必需的。研究表明，连接蛋白可以调节彼此的功能和稳定性，并通过在细胞膜10处彼此束缚来激活信号转导。目前手稿中提出的方案提供了有关连接蛋白差异表达，定位和正常鼠腺发育相互作用的有趣发现9 。鉴于连接蛋白定位对于蛋白质的功能至关重要，并且由于已知其与支架蛋白和许...

乳腺生长发育主要发生于出生后。这种器官在整个哺乳动物的生殖生活中不断地改造自己1 。成年乳腺上皮由腔内上皮细胞的内层和由基底膜2包围的主要由肌上皮细胞组成的基底细胞外层组成。为了对乳腺结构和发育的良好综述，读者可以参考Sternlicht 1 。通过间隙（GJ），紧密（TJ）和粘附（AJ）结的细胞 - 细胞相互作用对于腺体1,3,4,5,6的正常发育和功能是必需的。这些小鼠乳腺结节的主要成分是Cx26，Cx30，Cx32和Cx43（GJ）;紧密连接-1，-3，-4和-7和ZO-1（TJ）;和E-钙粘蛋白，P-钙粘蛋白和β-连环蛋白（AJ） 7,8 。这些不同连接蛋白的表达水平在乳腺发育过程中以阶段依赖的方式变化，这表明差异细胞 - 细胞相互作用的要求9 。 GJ，TJ和AJ在结构和功能上相互连接并将其他结构或调节蛋白连接到相邻细胞的相邻位点，从而产生连接性连接10 。连接关系的组成可以影响与下面的细胞骨架的桥接，以及连接通透性和稳定性，因此可以影响腺体8,9,10,11的功能。细胞间连接的组成部分存在于连接核酸中，或者彼此相互作用最近使用共免疫荧光（co-IF）和共免疫沉淀（co-IP） 9分析了乳腺发育的不同发育阶段。虽然其他技术允许评估蛋白质之间的功能关联，但这些方法在本手稿中没有提出。 由于蛋白质仅仅单独起作用，研究蛋白质 - 蛋白质相互作用（PPI），如信号转导和生物化学级联，对许多研究人员来说是必不可少的，可以提供关于蛋白质功能的重要信息。 Co-IF和微观分析有助于评估一些共享相同亚细胞空间的蛋白质。然而，目标的数量受到必须在不同动物中提高的抗体以及通过使用配备有不同波长激光器的共聚焦显微镜和用于复用的光谱检测器的抗体的限制。 Co-IP确认或揭示高亲和力的物理相互作用een两个或更多的蛋白质位于蛋白质复合物内。尽管开发了诸如荧光共振能量转移（FRET） 12和邻近连接测定（PLA） 13等新技术 ，其可以同时检测蛋白质的定位和相互作用，但共有IP仍然是一种适当和可负担的技术来研究内源蛋白。 本手册中描述的逐步方法将有助于蛋白质定位和PPI的研究，并指出在研究乳腺中的内源PPI时应避免的缺陷。该方法从对每种技术所需组织的不同保存程序的介绍开始。第1部分介绍了如何在三个步骤中研究蛋白质共定位:i）乳腺切片，ii）使用co-IF技术对不同蛋白质的双重或三重标记，以及iii）成像蛋白质定位。第2部分显示如何沉淀内源性蛋白质并以三个步骤鉴定其相互作用的蛋白质:i）裂解物制备，ii）间接蛋白质免疫沉淀，以及iii）通过SDS-PAGE和Western印迹结合配偶体鉴定。该方案的每一步都针对啮齿动物乳腺组织进行了优化，并产生了高质量，特异性和可重复的结果。该方案也可用作其他组织或细胞系中PPI研究的起点。

<table>
	<tbody>
		<tr>
			<td>Mice strain and stage&#160;</td>
			<td>St. Constant, Quebec, Canada</td>
			<td></td>
			<td>C57BL/6 Femals; pregnancy day 18 (P18) and lactation day 14 (L14), Charles River Canada&#160;</td>
		</tr>
		<tr>
			<td>PBS 10X (stock)</td>
			<td></td>
			<td></td>
			<td>1)&#160;&#160;&#160;&#160;&#160; Dissolve 80g NaCl (F.W.: 58.44), 2g KCl (F.W. 74.55), 26.8g Na2HPO4&#8226;7H2O (F.W. 268.07) and 2.4g KH2PO4 (F.W.:136.09) in 800ml distilled water.&#160; 
			2)&#160;&#160;&#160;&#160;&#160; Adjust the PH to 7.4&#160; 
			3)&#160;&#160;&#160;&#160;&#160; Add water to reach to the 1 litre final volume.&#160;</td>
		</tr>
		<tr>
			<td>TBS 10X (stock)</td>
			<td></td>
			<td></td>
			<td>1)&#160;&#160;&#160;&#160;&#160; Dissolve 60.5g TRIS, 87.6g NaCl in 800ml distilled water.&#160; 
			2)&#160;&#160;&#160;&#160;&#160; Adjust the PH to 7.5&#160; 
			3)&#160;&#160;&#160;&#160;&#160; Add water to reach to the 1 litre final volume.&#160;</td>
		</tr>
		<tr>
			<td>Name</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td>Comments</td>
		</tr>
		<tr>
			<td colspan="4">Part 1-Immunofluorescence</td>
		</tr>
		<tr>
			<td>Freezing media</td>
			<td>VWR International, Ville Mont-Royal, QC, Canada</td>
			<td>95067-840</td>
			<td>VMR frozen sections compound&#160;</td>
		</tr>
		<tr>
			<td>Microtome</td>
			<td>Mississauga, ON, Canada</td>
			<td>956640</td>
			<td>Microm HM525, Thermo fisher scientific HM525 NX Cryostat 115V 60Hz</td>
		</tr>
		<tr>
			<td>Blades</td>
			<td>C.L. Sturkey, Inc. Les Produits&#160;Scientifiques&#160;ESBE&#160;St-Laurent, QC, Canada</td>
			<td>&#160;BLM1001C</td>
			<td>High profile gold coated blades</td>
		</tr>
		<tr>
			<td>Pap pen</td>
			<td>Cedarlane, Burlington, ON, Canada</td>
			<td>8899</td>
			<td>Super PAP Pen, Thermo fisher scientific</td>
		</tr>
		<tr>
			<td>Microscopic slides</td>
			<td>Fisher Scientific, Burlington, ON, Canada</td>
			<td>12-550-15</td>
			<td>Fisherbrand&#160;Superfrost Plus Microscope Slides</td>
		</tr>
		<tr>
			<td>Formaldehyde</td>
			<td>BioShop Canada Inc, Burlington, ON, Canada</td>
			<td>FOR201.1</td>
			<td>Forlmadehyde</td>
		</tr>
		<tr>
			<td>Bovine Serum Albumin (BSA)</td>
			<td></td>
			<td></td>
			<td>Santa Cruz Biotechnology, Inc, California, USA</td>
		</tr>
		<tr>
			<td>Blocking solution</td>
			<td></td>
			<td></td>
			<td>3% BSA in TBS</td>
		</tr>
		<tr>
			<td>Wash solution</td>
			<td></td>
			<td></td>
			<td>TBS-Tween 20 0.1%</td>
		</tr>
		<tr>
			<td>Polysorbate 20</td>
			<td>Oakville, ON, Canada</td>
			<td>P 9416</td>
			<td>Tween 20, Sigma-Aldrich</td>
		</tr>
		<tr>
			<td>Mounting media</td>
			<td>Cedarlane, Burlington, ON</td>
			<td>17984-25(EM)</td>
			<td>Fluoromount-G</td>
		</tr>
		<tr>
			<td>First &#38; secondary antibodies&#160;</td>
			<td>Cell Signaling, Beverly, MA, USA</td>
			<td>Mentioned in Column D</td>
			<td>E-Cadherin (4A2) Mouse mAb (#14472s) 1/50 (Cell Signaling) with anti-mouse IgG Fab2 Alexa Fluor 555 (#4409s), Cell Signaling&#160;</td>
		</tr>
		<tr>
			<td>First &#38; secondary antibodies&#160;</td>
			<td>Life technologies, Waltham, MA, USA &#38; Cell Signaling, Beverly, MA, USA</td>
			<td>Mentioned in Column D</td>
			<td>Claudin-7 (#34-9100) 1/100 (Life Technologies) with anti-rabbit IgG Fab2 Alexa Fluor 488 (#4412s) (Cell Signaling)&#160;</td>
		</tr>
		<tr>
			<td>First &#38; secondary antibodies&#160;</td>
			<td>Santa Cruz Biotechnology, Inc, California, USA; Fischer Scientific, Burlington, ON, Canada&#160;</td>
			<td>Mentioned in Column D</td>
			<td>&#946;-Catenin Antibody (C-18): sc-1496 (SANTA CRUZ) with anti-Goat IgG (H+L) Alexa Fluor 568 (#A11057), Molecular Probe (Fisher Scientific)</td>
		</tr>
		<tr>
			<td>First &#38; secondary antibodies&#160;</td>
			<td>Life technologies, Waltham, MA, USA &#38; Cell Signaling, Beverly, MA, USA</td>
			<td>Mentioned in Column D</td>
			<td>Connexin26&#160; (#33-5800) 1/75 (Life Technologies) with anti-mouse IgG Fab2 Alexa Fluor 647 (#4410s)&#160;</td>
		</tr>
		<tr>
			<td>Nuclei stain</td>
			<td>Fisher Scientific, Burlington, ON, Canada</td>
			<td>D1306</td>
			<td>DAPI (4&#39;,6-Diamidino-2-Phenylindole, Dihydrochloride) 1/1000 in PBS</td>
		</tr>
		<tr>
			<td>Fluorescent microscope</td>
			<td>Nikon Canada, Mississauga, On, Canada</td>
			<td></td>
			<td>Nikon A1R+ confocal microscopic laser equipped with a spectral detector&#160;</td>
		</tr>
		<tr>
			<td>Software of IF images analysis</td>
			<td>Nikon Canada, Mississauga, On, Canada</td>
			<td></td>
			<td>NIS-elements software (version 4)</td>
		</tr>
		<tr>
			<td>Name</td>
			<td>Company</td>
			<td>Catalog Number</td>
			<td>Comments</td>
		</tr>
		<tr>
			<td colspan="4">Part 2-Immunoprecipitation</td>
		</tr>
		<tr>
			<td>Triple-detergent Lysis buffer (100ml) pH=8.0&#160;</td>
			<td></td>
			<td></td>
			<td>1) Mix 50mM TRIS (F.W.&#160;:121.14), 150mM NaCl (F.W.&#160;:58.44), 0.02% Sodium Azide, 0.1% SDS, 1% NONIdET P40, 0.5% Sodium Deoxycholate in 80ml distilled H2O.&#160; 
			2) Adjust the PH to 8.0 with HCl 6N (~0.5ml). 
			3) Adjust the volume to 100ml. Keep it in fridge.&#160; 
			At the day of protein extraction, use 1/100 NaVo3, 1/100 protease/phosphatase inhibitor and 1/25 NAF in calculated amount of Triple detergent lysis buffer: 
			Sodium Fluorid (stock) solution 1.25M (F.W. 41.98), Sodium Orthovanadate (stock) Solution 1M (F.W.: 183.9)</td>
		</tr>
		<tr>
			<td>Protease/phosphatase inhibitor</td>
			<td>Fisher Scientific, Burlington, ON</td>
			<td>78441</td>
			<td>Halt Protease and Phosphatase Inhibitor Cocktail, EDTA-free (100X)</td>
		</tr>
		<tr>
			<td>Protein dosage</td>
			<td>Thermo Scientific, Rockford, Illinois, USA</td>
			<td>23225</td>
			<td>Pierce BCA protein assay kit&#160;</td>
		</tr>
		<tr>
			<td>Tissue grinder</td>
			<td>Fisher Scientific, Burlington, ON</td>
			<td>FTH-115</td>
			<td>Power 125, Model FTH-115</td>
		</tr>
		<tr>
			<td>Magnetic beads and stand</td>
			<td>Millipore, Etobicoke, ON, Canada</td>
			<td></td>
			<td>PureProteome Protein G Magnetic Bead System (LSKMAGG02)</td>
		</tr>
		<tr>
			<td>Wash solution for IP</td>
			<td></td>
			<td></td>
			<td>PBS or PBS-Tween20 0.1% depending to the step</td>
		</tr>
		<tr>
			<td>Primary antibodies for immunoprecipitation</td>
			<td>Cell Signaling, Beverly, MA, USA</td>
			<td>Mentioned in coulmn D</td>
			<td>IgG Rabbit (rabbit (DA1E) mAb IgG Isotype control (#3900s) (Cell Signaling) 0.5 &#181;l/200 &#181;l</td>
		</tr>
		<tr>
			<td>Primary antibodies for immunoprecipitation</td>
			<td>Cell Signaling, Beverly, MA, USA</td>
			<td>Mentioned in coulmn D</td>
			<td>IgG Mouse mouse (G3A1) mAb IgG Isotype control (#5415s) (Cell Signaling) 0.5 &#181;l/200 &#181;l&#160;</td>
		</tr>
		<tr>
			<td>Primary antibodies for immunoprecipitation</td>
			<td>Sigma-Aldrich, Oakville, ON, Canada</td>
			<td>Mentioned in coulmn D</td>
			<td>Connexin43 (#C6219) (Sigma-Aldrich) 4 &#181;l/200 &#181;l&#160;</td>
		</tr>
		<tr>
			<td>Primary antibodies for immunoprecipitation</td>
			<td>Cell Signaling, Beverly, MA, USA</td>
			<td>Mentioned in coulmn D</td>
			<td>E-cadherin (4A2) Mouse mAb (#14472s) (Cell Signaling) 1 &#181;l/200 &#181;l&#160;</td>
		</tr>
		<tr>
			<td>Laemmli buffer&#160;</td>
			<td>BIO-RAD, Mississauga, Ontario, Canada</td>
			<td>1610747</td>
			<td>4x Laemmli Sample Buffer (Add &#946;-mercaptoethanol following manufacturer recommendation)</td>
		</tr>
		<tr>
			<td>Acidic glycine&#160;</td>
			<td>Fisher Scientific, Burlington, ON</td>
			<td>PB381-5</td>
			<td>0.2 M glycine; adjust pH=2.5 with HCl&#160;</td>
		</tr>
		<tr>
			<td>Tris&#160;</td>
			<td>Fisher Scientific, Burlington, ON</td>
			<td>BP152-1</td>
			<td>1 M (pH=8)&#160;</td>
		</tr>
		<tr>
			<td>SDS-PAGE acrylamide gels&#160;</td>
			<td>BIO-RAD, Mississauga, ON, Canada</td>
			<td>1610180 -5</td>
			<td>TGX Stain-Free FastCast Acrylamide Solutionss (7.8%, 10%, 12%)</td>
		</tr>
		<tr>
			<td>Running buffer 10x&#160;</td>
			<td>BIO-RAD, Mississauga, ON, Canada</td>
			<td>1704272</td>
			<td>Tris 30.3g/glycine 144.1g /SDS 10g in 1 litre distilled water</td>
		</tr>
		<tr>
			<td>Membranes</td>
			<td>BIO-RAD, Mississauga, ON, Canada</td>
			<td>1704272</td>
			<td>PVDF membranes, Trans-Blot Turbo RTA Mini PVDF Transfer Kit</td>
		</tr>
		<tr>
			<td>Transfer method</td>
			<td>BIO-RAD, Mississauga, ON, Canada</td>
			<td>1704155</td>
			<td>Trans-Blot Turbo Transfer System</td>
		</tr>
		<tr>
			<td>Dry Milk</td>
			<td>Smucker Food of Canada Co, Markham, ON, Canada</td>
			<td></td>
			<td>Fat Free Instant Skim Milk Powder, Carnation</td>
		</tr>
		<tr>
			<td>Blocking solution for blots</td>
			<td></td>
			<td></td>
			<td>5% dry milk in TBS-Tween 20 0.1%</td>
		</tr>
		<tr>
			<td>Washing solutions for blots</td>
			<td></td>
			<td></td>
			<td>TBS-Tween 20 0.1%</td>
		</tr>
		<tr>
			<td>Primary and secondary antibodies for blots (10ml)</td>
			<td>Sigma-Aldrich, Oakville, Ontario &#38; Abcam, Toronto, ON, Canada</td>
			<td>Mentioned in column D</td>
			<td>Connexin43 (#C6219) (Sigma-Aldrich) 1/2500 with HRP-conjugated Veriblot for IP secondary antibody (ab131366) 1/5000 (Abcam, Toronto, ON, Canada)</td>
		</tr>
		<tr>
			<td>Primary and secondary antibodies for blots (10ml)</td>
			<td>Cell Signaling, Beverly, MA, USA &#38; Abcam, Toronto, ON, Canada</td>
			<td>Mentioned in column D</td>
			<td>E-cadherin (24E10) rabbit mAb 1/1000 (#3195s) (Cell Signaling) 1/1000 with HRP-conjugated Veriblot for IP secondary antibody&#160; (ab131366) 1/5000 (Abcam, Toronto, ON, Canada)</td>
		</tr>
		<tr>
			<td>Primary and secondary antibodies for blots (10ml)</td>
			<td>Life technologies, Waltham, MA, USA &#38; Abcam, Toronto, ON, Canada</td>
			<td>Mentioned in column D</td>
			<td>Claudin-7 (#34-9100) (Life technologies) 1/1000 with HRP-conjugated Veriblot for IP secondary antibody (ab131366)&#160; 1/5000 (Abcam, Toronto, ON, Canada)</td>
		</tr>
		<tr>
			<td>Primary and secondary antibodies for blots (10ml)</td>
			<td>Life technologies, Waltham, MA, USA &#38; Abcam, Toronto, ON, Canada</td>
			<td>Mentioned in column D</td>
			<td>Claudin3&#160; (#34-1700) (Life technologies) 1/1000 with HRP-conjugated Veriblot for IP secondary antibody&#160; (ab131366) 1/5000 (Abcam, Toronto, ON, Canada)</td>
		</tr>
		<tr>
			<td>Luminol solution for signal detection on blots</td>
			<td>BIO-RAD, Mississauga, ON, Canada</td>
			<td>1705061&#160;</td>
			<td>Clarity Western ECL Blotting Substrate&#160;</td>
		</tr>
		<tr>
			<td>Imaging blots</td>
			<td>BIO-RAD, Mississauga, ON, Canada</td>
			<td>1708280</td>
			<td>ChemiDoc MP imaging system</td>
		</tr>
		<tr>
			<td>Analayzing blots</td>
			<td>BIO-RAD, Mississauga, ON, Canada</td>
			<td></td>
			<td>ImageLab 5.2 software&#160;</td>
		</tr>
	</tbody>
</table>

analysis of protein-protein interactions and co-localization between components of gap, tight, and adherens junctions in murine mammary glands

细胞间的相互作用在保持组织完整性和乳腺不同隔室之间的屏障方面发挥关键作用。这些相互作用由在相邻细胞之间形成核酸的连接蛋白提供。功能蛋白质错位和与其结合配偶体的物理缔合减少可导致功能丧失，从而导致器官功能障碍。因此，在正常和疾病相关组织中鉴定蛋白质定位和蛋白质 - 蛋白质相互作用（PPI）对于找到导致疾病发展或发育状态改变的新证据和机制是至关重要的。该手稿提供了两步法评估鼠乳腺中的PPI。在方案1中，描述了使用针对感兴趣的蛋白质产生的抗体，随后用荧光染料标记的二抗进行共免疫荧光（co-IF）的方法。虽然共同所有为了证明蛋白质的接近程度，它确实有可能研究其物理相互作用。因此，在协议第2节中提供了共免疫沉淀（co-IP）的详细方案。该方法用于确定蛋白质之间的物理相互作用，而不确认这些相互作用是直接还是间接的。在过去几年中，共同中心和共同IP技术已经证明，细胞间连接的某些组成部分共同定位并相互作用，从而在乳腺发育过程中产生不同阶段依赖的连接性核酸。

为了确定GJ，AJ和TJ组分是否可以在乳腺中相互作用，首先进行共IF测定。分别用特异性抗体探测Cx26，GJ蛋白和β-Catenin，一种AJ蛋白，分别用荧光团缀合的小鼠-647（绿色，假色）和山羊-568（红色）抗体（ 图1B和C ） 。数据显示，在哺乳期第7天（L7），它们在小鼠乳腺的上皮细胞的细胞膜上共同定位，如黄色所反映的（ 图1D ）。其次，?...

Watch this Scientific Journal Video about Analysis of Protein-protein Interactions and Co-localization Between Components of Gap, Tight, and Adherens Junctions in Murine Mammary Glands at JoVE.com

Analysis of Protein-protein Interactions and Co-localization Between Components of Gap, Tight, and Adherens Junctions in Murine Mammary Glands

细胞间连接是乳腺阶段特异性功能和发育的必需条件。该手稿提供了一个详细的方法，用于研究蛋白质 - 蛋白质相互作用（PPI）和使用鼠乳腺的共定位。这些技术允许调查不同发育阶段的细胞间连接之间的物理联系的动力学。

蛋白质 - 蛋白质相互作用的分析和鼠乳腺中间隙，紧密和粘附连接部位之间的共定位

Cell-cell interactions play a pivotal role in preserving tissue integrity and the barrier between the different compartments of the mammary gland. These ...

analysis-protein-protein-interactions-co-localization-between

Research

JoVE Journal

Developmental Biology

10.0K 次观看.  INRS, Institut Armand-Frappier. 细胞间连接是乳腺阶段特异性功能和发育的必需条件。该手稿提供了一个详细的方法，用于研究蛋白质 - 蛋白质相互作用（PPI）和使用鼠乳腺的共定位。这些技术允许调查不同发育阶段的细胞间连接之间的物理联系的动力学。 

视频: Analysis of Protein-protein Interactions and Co-localization Between Components of Gap, Tight, and Adherens Junctions in Murine Mammary Glands

Analysis of Zebrafish Larvae Skeletal Muscle Integrity with Evans Blue Dye

The zebrafish model is an emerging system for the study of neuromuscular disorders. In the study of neuromuscular diseases, the integrity of the muscle membrane is a critical disease determinant. To date, numerous neuromuscular conditions display degenerating muscle fibers with abnormal membrane integrity; this is most commonly observed in muscular dystrophies. Evans Blue Dye (EBD) is a vital, cell permeable dye that is rapidly taken into degenerating, damaged, or apoptotic cells; in contrast, it is not taken up by cells with an intact membrane. EBD injection is commonly employed to ascertain muscle integrity in mouse models of neuromuscular diseases. However, such EBD experiments require muscle dissection and/or sectioning prior to analysis. In contrast, EBD uptake in zebrafish is visualized in live, intact preparations. Here, we demonstrate a simple and straightforward methodology for performing EBD injections and analysis in live zebrafish. In addition, we demonstrate a co-injection strategy to increase efficacy of EBD analysis. Overall, this video article provides an outline to perform EBD injection and characterization in zebrafish models of neuromuscular disease.

In this study, we describe a straightforward method to perform Evans Blue Dye (EBD) analysis on zebrafish larvae. This technique is a powerful tool for the characterization of skeletal muscle integrity and delineation of zebrafish models of muscular dystrophy, and is a valuable method for the development of novel therapeutics.

斑马鱼幼虫骨骼肌诚信与伊文思蓝分析

The zebrafish model is an emerging system for the study of neuromuscular disorders.  In the study of neuromuscular diseases, the integrity of the muscle ...

科研

发育生物学

Spatial and Temporal Analysis of Active ERK in the C. elegans Germline

The evolutionarily conserved&#160;extracellular signal transducing RTK-RAS-ERK pathway is an important kinase-signaling cascade that controls multiple cellular and developmental processes principally via activation of ERK, the terminal kinase of the pathway. Tight regulation of ERK activity is essential for normal development and homeostasis; overly active ERK results in excessive cellular proliferation, while underactive ERK causes cell death. C. elegans is a powerful model system that has helped characterize the function and regulation of RTK-RAS-ERK signaling pathway during development. In particular, the RTK-RAS-ERK pathway is essential for C. elegans germline development, which is the focus of this method. Using antibodies specific to the active, diphosphorylated form of ERK (dpERK), the stereotypical localization pattern can be visualized within the germline. Because this pattern is both spatially and temporally controlled, the ability to reproducibly assay dpERK is useful to identify regulators of the pathway that affect dpERK signal duration and amplitude and thus germline development. Here we demonstrate how to successfully dissect, stain, and image dpERK within the C. elegans gonad. This method can be adapted for spatial localization of any signaling or structural protein in the C. elegans gonad, provided an antibody compatible with immunofluorescence is available.

Spatial and Temporal Analysis of Active ERK in the C. elegans Germline

We present an immunofluorescence&#160;imaging-based method for spatial and temporal localization of active ERK in the dissected C. elegans gonad. The protocol described here can be adapted for visualization of any signaling or structural protein in the C. elegans gonad, provided a suitable antibody reagent is available.

在Active ERK的时空分析<em&gt;℃。线虫</em&gt;生殖系

The evolutionarily conserved&#160;extracellular signal transducing RTK-RAS-ERK pathway is an important kinase-signaling cascade that controls multiple ...

Co-localization of Cell Lineage Markers and the Tomato Signal

The cell lineage tracing system has been used predominantly in developmental biology studies. The use of Cre recombinase allows for the activation of the reporter in a specific cell line and all progeny. Here, we used the cell lineage tracing technique to demonstrate that chondrocytes directly transform into osteoblasts and osteocytes during long bone and mandibular condyle development using two kinds of Cre, Col10a1-Cre and Aggrecan-CreERT2 (Agg-CreERT2), crossed with Rosa26tdTomato. Both Col10 and aggrecan are well-recognized markers for chondrocytes.
On this basis, we developed a new method-cell lineage tracing in conjunction with fluorescent immunohistochemistry-to define cell fate by analyzing the expression of specific cell markers. Runx2 (a marker for early-stage osteogenic cells) and Dentin matrix protein1 (DMP1; a marker for late-stage osteogenic cells) were used to identify chondrocyte-derived bone cells and their differentiation status. This combination not only broadens the application of cell lineage tracing, but also simplifies the generation of compound mice. More importantly, the number, location, and differentiation statuses of parent cell progeny are displayed simultaneously, providing more information than cell lineage tracing alone. In conclusion, the co-application of cell lineage tracing techniques and immunofluorescence is a powerful tool for investigating cell biology in vivo.

We developed two sets of tracing combinations in Rosa26tdtomato (ubiquitously expressed in all cells)/Cre (specifically expressed in chondrocytes) mice: one with 2.3Col1a1-GFP (specific to osteoblasts) and one with immunofluorescence (specific to bone cells). The data demonstrate the direct transformation of chondrocytes into bone cells.

细胞系标记的共定位和番茄信号

The cell lineage tracing system has been used predominantly in developmental biology studies. The use of Cre recombinase allows for the activation of the ...

Visualization and Quantitative Analysis of Embryonic Angiogenesis in Xenopus tropicalis

Blood vessels supply oxygen and nutrients throughout the body, and the formation of the vascular network is under tight developmental control. The efficient in vivo visualization of blood vessels and the reliable quantification of their complexity are key to understanding the biology and disease of the vascular network. Here, we provide a detailed method to visualize blood vessels with a commercially available fluorescent dye, human plasma acetylated low density lipoprotein DiI complex (DiI-AcLDL), and to quantify their complexity in Xenopus tropicalis. Blood vessels can be labeled by a simple injection of DiI-AcLDL into the beating heart of an embryo, and blood vessels in the entire embryo can be imaged in live or fixed embryos. Combined with gene perturbation by the targeted microinjection of nucleic acids and/or the bath application of pharmacological reagents, the roles of a gene or of a signaling pathway on vascular development can be investigated within one week without resorting to sophisticated genetically engineered animals. Because of the well-defined venous system of Xenopus and its stereotypic angiogenesis, the sprouting of pre-existing vessels, vessel complexity can be quantified efficiently after perturbation experiments. This relatively simple protocol should serve as an easily accessible tool in diverse fields of cardiovascular research.

Visualization and Quantitative Analysis of Embryonic Angiogenesis in Xenopus tropicalis

This protocol demonstrates a fluorescence-based method to visualize the vasculature and to quantify its complexity in Xenopus tropicalis. Blood vessels can be imaged minutes after the injection of a fluorescent dye into the beating heart of an embryo after genetic and/or pharmacological manipulations to study cardiovascular development in vivo.

胚胎血管生成的可视化和定量分析<em&gt;热带非洲爪蟾</em

Blood vessels supply oxygen and nutrients throughout the body, and the formation of the vascular network is under tight developmental control. The ...

Transfer of Mammary Gland-forming Ability Between Mammary Basal Epithelial Cells and Mammary Luminal Cells via Extracellular Vesicles/Exosomes

Cells can communicate via exosomes, ~100-nm extracellular vesicles (EVs) that contain proteins, lipids, and nucleic acids. Non-adherent/mesenchymal mammary epithelial cell (NAMEC)-derived extracellular vesicles can be isolated from NAMEC medium via differential ultracentrifugation. Based on their density, EVs can be purified via ultracentrifugation at 110,000 x g. The EV preparation from ultracentrifugation can be further separated using a continuous density gradient to prevent contamination with soluble proteins. The purified EVs can then be further evaluated using nanoparticle-tracking analysis, which measures the size and number of vesicles in the preparation. The extracellular vesicles with a size ranging from 50 to 150 nm are exosomes. The NAMEC-derived EVs/exosomes can be ingested by mammary epithelial cells, which can be measured by flow cytometry and confocal microscopy. Some mammary stem cell properties (e.g., mammary gland-forming ability) can be transferred from the stem-like NAMECs to mammary epithelial cells via the NAMEC-derived EVs/exosomes. Isolated primary EpCAMhi/CD49flo luminal mammary epithelial cells cannot form mammary glands after being transplanted into mouse fat pads, while EpCAMlo/CD49fhi basal mammary epithelial cells form mammary glands after transplantation. Uptake of NAMEC-derived EVs/exosomes by EpCAMhi/CD49flo luminal mammary epithelial cells allows them to generate mammary glands after being transplanted into fat pads. The EVs/exosomes derived from stem-like mammary epithelial cells transfer mammary gland-forming ability to EpCAMhi/CD49flo luminal mammary epithelial cells.

This protocol describes methods for purifying, quantitating, and characterizing extracellular vesicles (EVs)/exosomes from non-adherent/mesenchymal mammary epithelial cells and for using them to transfer mammary gland-forming ability to luminal mammary epithelial cells. EVs/exosomes derived from stem-like mammary epithelial cells can transfer this cell property to cells that ingest the EVs/exosomes.

通过细胞外囊泡/外来体转移乳腺基质上皮细胞和乳腺腔细胞之间的乳腺形成能力

Cells can communicate via exosomes, ~100-nm extracellular vesicles (EVs) that contain proteins, lipids, and nucleic acids. Non-adherent/mesenchymal ...

Quantifying Branching Density in Rat Mammary Gland Whole-mounts Using the Sholl Analysis Method

An increasing number of studies are utilizing the rodent mammary gland as an endpoint for assessing the developmental toxicity of a chemical exposure. The effects these exposures have on mammary gland development are typically evaluated using either basic dimensional measurements or by scoring morphological characteristics. However, the broad range of methods for interpreting developmental changes could lead to inconsistent translations across laboratories. A common method of assessment is needed so that proper interpretations can be formed from data being compared across studies. The present study describes the application of the Sholl analysis method to quantify mammary gland branching characteristics. The Sholl method was originally developed for use in quantifying neuronal dendritic patterns. By using ImageJ, an open-source image analysis software package, and a plugin developed for this analysis, the mammary gland branching density and the complexity of a mammary gland from a peripubertal female rat were determined. The methods described here will enable the use of the Sholl analysis as an effective tool for quantifying an important characteristic of mammary gland development.

Mammary gland development in the rodent has typically been evaluated using descriptive assessments or by measuring basic physical attributes. Branching density is an indicator of mammary development that is difficult to quantify objectively. This protocol describes a reliable method for the quantitative assessment of mammary gland branching characteristics.

使用Sholl分析方法量化大鼠乳腺组织中的分支密度

An increasing number of studies are utilizing the rodent mammary gland as an endpoint for assessing the developmental toxicity of a chemical exposure. The ...

A Novel Mammary Fat Pad Transplantation Technique to Visualize the Vessel Generation of Vascular Endothelial Stem Cells

Endothelial cells (ECs) are the fundamental building blocks of the vascular architecture and mediate vascular growth and remodeling to ensure proper vessel development and homeostasis. However, studies on endothelial lineage hierarchy remain elusive due to the lack of tools to gain access as well as to directly evaluate their behavior in vivo. To address this shortcoming, a new tissue model to study angiogenesis using the mammary fat pad has been developed. The mammary gland develops mostly in the postnatal stages, including puberty and pregnancy, during which robust epithelium proliferation is accompanied by extensive vascular remodeling. Mammary fat pads provide space, matrix, and rich angiogenic stimuli from the growing mammary epithelium. Furthermore, mammary fat pads are located outside the peritoneal cavity, making them an easily accessible grafting site for assessing the angiogenic potential of exogenous cells. This work also describes an efficient tracing approach using fluorescent reporter mice to specifically label the targeted population of vascular endothelial stem cells (VESCs) in vivo. This lineage tracing method, coupled with subsequent tissue whole-mount microscopy, enable the direct visualization of targeted cells and their descendants, through which the proliferation capability can be quantified and the differentiation commitment can be fate-mapped. Using these methods, a population of bipotent protein C receptor (Procr) expressing VESCs has recently been identified in multiple vascular systems. Procr+ VESCs, giving rise to both new ECs and pericytes, actively contribute to angiogenesis during development, homeostasis, and injury repair. Overall, this manuscript describes a new mammary fat pad transplantation and in vivo lineage tracing techniques that can be used to evaluate the stem cell properties of VESCs.

This work demonstrates a novel approach to assess the proliferation, differentiation, and vessel-forming potential of vascular endothelial stem cells (VESCs) through mammary fat pad transplantation followed by whole-mount tissue preparation for microscopic observation. A lineage tracing strategy to investigate the behavior of VESCs in vivo is also presented.

新型乳腺脂肪移植技术可视化血管内皮干细胞的血管生成

Endothelial cells (ECs) are the fundamental building blocks of the vascular architecture and mediate vascular growth and remodeling to ensure proper ...

Correlative Super-resolution and Electron Microscopy to Resolve Protein Localization in Zebrafish Retina

We present a method to investigate the subcellular protein localization in the larval zebrafish retina by combining super-resolution light microscopy and scanning electron microscopy. The sub-diffraction limit resolution capabilities of super-resolution light microscopes allow improving the accuracy of the correlated data. Briefly, 110 nanometer thick cryo-sections are transferred to a silicon wafer and, after immunofluorescence staining, are imaged by super-resolution light microscopy. Subsequently, the sections are preserved in methylcellulose and platinum shadowed prior to imaging in a scanning electron microscope (SEM). The images from these two microscopy modalities are easily merged using tissue landmarks with open source software. Here we describe the adapted method for the larval zebrafish retina. However, this method is also applicable to other types of tissues and organisms. We demonstrate that the complementary information obtained by this correlation is able to resolve the expression of mitochondrial proteins in relation with the membranes and cristae of mitochondria as well as to other compartments of the cell.

This protocol describes the necessary steps to obtain subcellular protein localization results on zebrafish retina by correlating super-resolution light microscopy and scanning electron microscopy images.

斑马鱼视网膜蛋白定位的相关超分辨和电镜观察

We present a method to investigate the subcellular protein localization in the larval zebrafish retina by combining super-resolution light microscopy and ...

Dissection and Immunofluorescent Staining of Mushroom Body and Photoreceptor Neurons in Adult Drosophila melanogaster Brains

Nervous system development involves a sequential series of events that are coordinated by several signaling pathways and regulatory networks. Many of the proteins involved in these pathways are evolutionarily conserved between mammals and other eukaryotes, such as the fruit fly Drosophila melanogaster, suggesting that similar organizing principles exist during the development of these organisms. Importantly, Drosophila has been used extensively to identify cellular and molecular mechanisms regulating processes that are required in mammals including neurogenesis, differentiation, axonal guidance, and synaptogenesis. Flies have also been used successfully to model a variety of human neurodevelopmental diseases. Here we describe a protocol for the step-by-step microdissection, fixation, and immunofluorescent localization of proteins within the adult Drosophila brain. This protocol focuses on two example neuronal populations, mushroom body neurons and retinal photoreceptors, and includes optional steps to trace individual mushroom body neurons using Mosaic Analysis with a Repressible Cell Marker (MARCM) technique. Example data from both wild-type and mutant brains are shown along with a brief description of a scoring criteria for axonal guidance defects. While this protocol highlights two well-established antibodies for investigating the morphology of mushroom body and photoreceptor neurons, other Drosophila brain regions and the localization of proteins within other brain regions can also be investigated using this protocol.

Dissection and Immunofluorescent Staining of Mushroom Body and Photoreceptor Neurons in Adult Drosophila melanogaster Brains

This protocol describes the dissection and immunostaining of adult Drosophila melanogaster brain tissues. Specifically, this protocol highlights the use of Drosophila mushroom body and photoreceptor neurons as example neuronal subsets that can be accurately used to uncover general principles underlying many aspects of neuronal development.

成人果蝇脑内蘑菇体和感光神经元的解剖和荧光染色

Nervous system development involves a sequential series of events that are coordinated by several signaling pathways and regulatory networks. Many of the ...

Kinetic Analysis of Vasculogenesis Quantifies Dynamics of Vasculogenesis and Angiogenesis In Vitro

Vasculogenesis is a complex process by which endothelial stem and progenitor cells undergo de novo vessel formation. Quantitative assessment of vasculogenesis has become a central readout of endothelial progenitor cell functionality, and therefore, several attempts have been made to improve both in vitro and in vivo vasculogenesis models. However, standard methods are limited in scope, with static measurements failing to capture many aspects of this highly dynamic process. Therefore, the goal of developing this novel protocol was to assess the kinetics of in vitro vasculogenesis in order to quantitate rates of network formation and stabilization, as well as provide insight into potential mechanisms underlying vascular dysfunction. Application of this protocol is demonstrated using fetal endothelial colony forming cells (ECFCs) exposed to maternal diabetes mellitus. Fetal ECFCs were derived from umbilical cord blood following birth, cultured, and plated in slides containing basement membrane matrix, where they underwent vasculogenesis. Images of the entire slide wells were acquired using time-lapse phase contrast microscopy over 15 hours. Images were analyzed for derivation of quantitative data using an analysis software called Kinetic Analysis of Vasculogenesis (KAV). KAV uses image segmentation followed by skeletonization to analyze network components from stacks of multi-time point phase contrast images to derive ten parameters (9 measured, 1 calculated) of network structure including: closed networks, network areas, nodes, branches, total branch length, average branch length, triple-branched nodes, quad-branched nodes, network structures, and the branch to node ratio. Application of this protocol identified altered rates of vasculogenesis in ECFCs obtained from pregnancies complicated by diabetes mellitus. However, this technique has broad implications beyond the scope reported here. Implementation of this approach will enhance mechanistic assessment and improve functional readouts of vasculogenesis and other biologically important branching processes in numerous cell types or disease states.

Kinetic Analysis of Vasculogenesis Quantifies Dynamics of Vasculogenesis and Angiogenesis In Vitro

Here, we present a protocol for time-lapse imaging and analysis of vasculogenesis in vitro using phase contrast microscopy coupled with the open source software, Kinetic Analysis of Vasculogenesis. This protocol can be applied to quantitatively assess the vasculogenic potential of numerous cell types or experimental conditions that model vascular disease.

蛋白质 - 蛋白质相互作用的分析和鼠乳腺中间隙，紧密和粘附连接部位之间的共定位

摘要

探索更多视频

此视频中的章节