بدعم جزئي من وR01NS064593 R21ES016636 (KV). تم إجراء الفحص المجهري في جامعة فرجينيا كومنولث - قسم البيولوجيا العصبية ومرفق المجهر تشريح، بدعم، في جزء منه، وذلك بتمويل من المعاهد الوطنية للصحة، مركز NINDS 5P30NS047463 منحة الأساسية. تم شراء القرص الغزل مبائر المجهر مع جائزة NIH-NCRR (1S10RR027957).

<ol>
	<li>Botuyan, M. V., Lee, J., Ward, I. M., Kim, J. E., Thompson, J. R., Chen, J., Mer, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structural+basis+for+the+methylation+state-specific+recognition+of+histone+H4-K20+by+53BP1+and+Crb2+in+DNA+repair.">Structural basis for the methylation state-specific recognition of histone H4-K20 by 53BP1 and Crb2 in DNA repair.</a> Cell. 127, 1361-1373 (2006).</li><li>Dimitrova, N., Chen, Y. C., Spector, D. L., de Lange, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=53BP1+promotes+non-homologous+end+joining+of+telomeres+by+increasing+chromatin+mobility.">53BP1 promotes non-homologous end joining of telomeres by increasing chromatin mobility.</a> Nature. 456, 524-528 (2008).</li><li>Feuerhahn, S., Egly, 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=Tools+to+study+DNA+repair:+what's+in+the+box.">Tools to study DNA repair: what's in the box.</a> Trends Genet. 24, 467-474 (2008).</li><li>Giunta, S., Belotserkovskaya, R., Jackson, S. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=DNA+damage+signaling+in+response+to+double-strand+breaks+during+mitosis.">DNA damage signaling in response to double-strand breaks during mitosis.</a> J. Cell Biol. 190, 197-207 (2010).</li><li>Giunta, S., Jackson, S. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Give+me+a+break,+but+not+in+mitosis:+the+mitotic+DNA+damage+response+marks+DNA+double-strand+breaks+with+early+signaling+events.">Give me a break, but not in mitosis: the mitotic DNA damage response marks DNA double-strand breaks with early signaling events.</a> Cell Cycle. 10, 1215-1221 (2011).</li><li>Golding, S. E., Morgan, R. N., Adams, B. R., Hawkins, A. J., Povirk, L. F., Valerie, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pro-survival+AKT+and+ERK+signaling+from+EGFR+and+mutant+EGFRvIII+enhances+DNA+double-strand+break+repair+in+human+glioma+cells.">Pro-survival AKT and ERK signaling from EGFR and mutant EGFRvIII enhances DNA double-strand break repair in human glioma cells.</a> Cancer Biol. Ther. 8, 730-738 (2009).</li><li>Huyen, Y., Zgheib, O., Ditullio, R. A., Gorgoulis, V. G., Zacharatos, P., Petty, T. J., Sheston, E. A., Mellert, H. S., Stavridi, E. S., Halazonetis, T. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Methylated+lysine+79+of+histone+H3+targets+53BP1+to+DNA+double-strand+breaks.">Methylated lysine 79 of histone H3 targets 53BP1 to DNA double-strand breaks.</a> Nature. 432, 406-411 (2004).</li><li>Jackson, S. P., Bartek, 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+DNA-damage+response+in+human+biology+and+disease.">The DNA-damage response in human biology and disease.</a> Nature. 461, 1071-1078 (2009).</li><li>Kanda, T., Sullivan, K. F., Wahl, G. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Histone-GFP+fusion+protein+enables+sensitive+analysis+of+chromosome+dynamics+in+living+mammalian+cells.">Histone-GFP fusion protein enables sensitive analysis of chromosome dynamics in living mammalian cells.</a> Curr. Biol. 8, 377-385 (1998).</li><li>Massignani, M., Canton, I., Sun, T., Hearnden, V., Macneil, S., Blanazs, A., Armes, S. P., Lewis, A., Battaglia, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enhanced+fluorescence+imaging+of+live+cells+by+effective+cytosolic+delivery+of+probes.">Enhanced fluorescence imaging of live cells by effective cytosolic delivery of probes.</a> PLoS One. 5, e10459 (2010).</li><li>Nakamura, K., Sakai, W., Kawamoto, T., Bree, R. T., Lowndes, N. F., Takeda, S., Taniguchi, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetic+dissection+of+vertebrate+53BP1:+a+major+role+in+non-homologous+end+joining+of+DNA+double+strand+breaks.">Genetic dissection of vertebrate 53BP1: a major role in non-homologous end joining of DNA double strand breaks.</a> DNA Repair (Amst). 5, 741-749 (2006).</li><li>Schultz, L. B., Chehab, N. H., Malikzay, A., Halazonetis, T. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=p53+binding+protein+1+(53BP1)+is+an+early+participant+in+the+cellular+response+to+DNA+double-strand+breaks.">p53 binding protein 1 (53BP1) is an early participant in the cellular response to DNA double-strand breaks.</a> J. Cell. Biol. 151, 1381-1390 (2000).</li><li>Valerie, K., Povirk, L. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regulation+and+mechanisms+of+mammalian+double-strand+break+repair.">Regulation and mechanisms of mammalian double-strand break repair.</a> Oncogene. 22, 5792-5812 (2003).</li><li>Wang, B., Matsuoka, S., Carpenter, P. B., Elledge, S. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=53BP1,+a+mediator+of+the+DNA+damage+checkpoint.">53BP1, a mediator of the DNA damage checkpoint.</a> Science. 298, 1435-1438 (2002).</li><li>Ward, I. M., Minn, K., Jorda, K. G., Chen, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Accumulation+of+checkpoint+protein+53BP1+at+DNA+breaks+involves+its+binding+to+phosphorylated+histone+H2AX.">Accumulation of checkpoint protein 53BP1 at DNA breaks involves its binding to phosphorylated histone H2AX.</a> J. Biol. Chem. 278, 19579-19582 (2003).</li></ol>

الإعلان عن أي تضارب في المصالح.

الحفاظ على سلامة الجينوم هو أمر حاسم لبقاء الخلية. الفشل في الحفاظ على نتائج الجينوم في الشيخوخة المبكرة، التسرطن أو الموت، 8. هناك اهتمام كبير في كيفية عمل المميزين DDR، النابعة من أهميته للبحوث الأساسية والسريرية على حد سواء. وقد تم تطوير العديد من التقنيات على...

<table border="1" style=";text-align:right;direction:rtl"><tbody><tr><td> نتاج </td><td> شركة </td></tr><tr><td> أطباق CellStar الثقافة </td><td> غرينر بيو واحد </td></tr><tr><td> FluroDish الأطباق الزجاجية القاع </td><td> العالم آلات دقيقة، وشركة </td></tr><tr><td> MEM وسائل الإعلام </td><td> GIBCO </td></tr><tr><td> غير الأحماض الأمينية الأساسية </td><td> GIBCO </td></tr><tr><td> الأحماض الأمينية </td><td> GIBCO </td></tr><tr><td> الفيتامينات </td><td> GIBCO </td></tr><tr><td> البيروفات الصوديوم </td><td> إينفيتروجن </td></tr><tr><td> البنسلين / الستربتوميسين </td><td> HyClone </td></tr><tr><td> المصل البقري الجنين </td><td> GIBCO </td></tr><tr><td> N-Myc على WT-53BP1 pLPC-بورو؛ بلازميد 19836 </td><td> Addgene </td></tr><tr><td> pCLNR-H2BG؛ البلازميد 17735 </td><td> Addgene </td></tr><tr><td> SuperFect </td><td> QIAGEN </td></tr><tr><td> زايس خلية المراقب SD نظام التصوير </td><td> زايس </td></tr><tr><td> AxioVision (الإصدار 4.8.2) </td><td> زايس </td></tr><tr><td> زايس Immersol W النفط </td><td> زايس </td></tr><tr><td> برنامج Volocity (الإصدار 6.0) </td><td> PerkinElmer </td></tr></tbody></table>

two- and three-dimensional live cell imaging of dna damage response proteins

انقر نقرا مزدوجا حبلا فواصل (DSBs) هي الأكثر ضررا آفات الحمض النووي خلية يمكن أن تواجهها. إذا تركت دون اصلاح، DSBs الميناء إمكانيات كبيرة لتوليد الطفرات والتشوهات الكروموسومية 1. لمنع هذه الصدمة من عدم الاستقرار الجيني تحفيز، لا بد للخلايا للكشف عن DSBs، تنشيط استجابة الحمض النووي من التلف (DDR)، وإصلاح الحمض النووي. عندما حفز، وDDR تعمل على الحفاظ على سلامة الجينوم عن طريق إحداث خلية للسماح اعتقال دورة للإصلاح أن يتم إجبار الخلية أو الخضوع لموت الخلايا المبرمج. الآليات السائدة لإصلاح جهاز تسوية المنازعات من خلال الانضمام تحدث في نهاية امتماثلان (NHEJ) وإعادة التركيب مثلي إصلاح (HRR) (مشاركة في 2). هناك العديد من البروتينات التي يجب أن أنشطة مدبرة بدقة لDDR بشكل صحيح. هنا، نحن تصف طريقة ل2 - و 3 الأبعاد (D) من التصور واحدة من هذه البروتينات، 53BP1. البروتين P53 ملزم 1 (53BP1) يموضع إلى مناطقDSBs عن طريق الربط بين تعديل الهستونات 3،4، وتشكيل بؤر داخل 5-15 دقائق 5. ويعتقد أن التعديلات هيستون والتوظيف من البروتينات وغيرها من DDR 53BP1 إلى مواقع DSB لتسهيل إعادة ترتيب الهيكلية للونين حول مناطق الضرر والمساهمة في إصلاح الحمض النووي 6. إلى ما بعد المشاركة المباشرة في الإصلاح، وقد وصفت أدوار إضافية ل53BP1 في DDR، مثل تنظيم داخل نقطة تفتيش تابعة لل-S، G2 نقطة تفتيش / M، وتفعيل المصب البروتينات DDR 7-9. مؤخرا، تم اكتشاف أن 53BP1 لا تشكل بؤر ردا على الحمض النووي من التلف الناجم أثناء الانقسام، والانتظار بدلا من ذلك لدخول الخلايا G1 قبل إضفاء الطابع المحلي على مقربة من DSBs 6. تم العثور على البروتينات مثل DDR 53BP1 لربط مع الهياكل الإنقسامية (مثل kinetochores) خلال التقدم من خلال الانقسام 10. ونحن في هذا البروتوكول وصف استخدام 2 - 3-D والتصوير الخلية الحية لتصورتشكيل بؤر 53BP1 ردا على وكيل camptothecin DNA الضارة (CPT)، وكذلك السلوك 53BP1 خلال الانقسام. Camptothecin هو topoisomerase I المانع الذي يسبب في المقام الأول DSBs خلال تكرار الحمض النووي. لإنجاز هذا، استخدمنا الموصوفة سابقا 53BP1-mCherry انصهار بروتين فلوري بناء يتألف من مجال البروتين 53BP1 قادرة على ربط DSBs 11. وبالإضافة إلى ذلك، استخدمنا هيستون H2B-GFP البروتين الانصهار الفلورسنت بناء قادرة على رصد ديناميات ونين في جميع أنحاء دورة الخلية ولكن بشكل خاص خلال الانقسام 12. الحية التصوير خلية في أبعاد متعددة هو أداة ممتازة لتعميق فهمنا لوظيفة البروتينات في الخلايا حقيقية النواة DDR.

Watch this Scientific Journal Video about Two- and Three-Dimensional Live Cell Imaging of DNA Damage Response Proteins at JoVE.com

Two- and Three-Dimensional Live Cell Imaging of DNA Damage Response Proteins

يصف هذا البروتوكول طريقة لتصور على الحمض النووي المزدوج حبلا البروتين كسر إشارة تنشيط ردا على الحمض النووي من التلف وكذلك التوطين خلال الانقسام.

عامين والتصوير الثلاثي الابعاد لايف خلية من البروتينات DNA الاستجابة الأضرار

Double-strand breaks (DSBs) are the most deleterious DNA lesions a cell can encounter. If left unrepaired, DSBs harbor great potential to generate ...

two-three-dimensional-live-cell-imaging-dna-damage-response

Research

JoVE Journal

Biology

14.0K Views.  Virginia Commonwealth University. يصف هذا البروتوكول طريقة لتصور على الحمض النووي المزدوج حبلا البروتين كسر إشارة تنشيط ردا على الحمض النووي من التلف وكذلك التوطين خلال الانقسام.

Video: Two- and Three-Dimensional Live Cell Imaging of DNA Damage Response Proteins

Microfabrication of Chip-sized Scaffolds for Three-dimensional Cell cultivation

Using microfabrication technologies is a prerequisite to create scaffolds of reproducible geometry and constant quality for three-dimensional cell cultivation. These technologies offer a wide spectrum of advantages not only for manufacturing but also for different applications. The size and shape of formed cell clusters can be influenced by the exact and reproducible architecture of the microfabricated scaffold and, therefore, the diffusion path length of nutrients and gases can be controlled.1 This is unquestionably a useful tool to prevent apoptosis and necrosis of cells due to an insufficient nutrient and gas supply or removal of cellular metabolites.
Our polymer chip, called CellChip, has the outer dimensions of 2 x 2 cm with a central microstructured area. This area is subdivided into an array of up to 1156 microcontainers with a typical dimension of 300 m edge length for the cubic design (cp- or cf-chip) or of 300 m diameter and depth for the round design (r-chip).2
So far, hot embossing or micro injection moulding (in combination with subsequent laborious machining of the parts) was used for the fabrication of the microstructured chips. Basically, micro injection moulding is one of the only polymer based replication techniques that, up to now, is capable for mass production of polymer microstructures.3 However, both techniques have certain unwanted limitations due to the processing of a viscous polymer melt with the generation of very thin walls or integrated through holes. In case of the CellChip, thin bottom layers are necessary to perforate the polymer and provide small pores of defined size to supply cells with culture medium e.g. by microfluidic perfusion of the containers.
In order to overcome these limitations and to reduce the manufacturing costs we have developed a new microtechnical approach on the basis of a down-scaled thermoforming process. For the manufacturing of highly porous and thin walled polymer chips, we use a combination of heavy ion irradiation, microthermoforming and track etching. In this so called "SMART" process (Substrate Modification And Replication by Thermoforming) thin polymer films are irradiated with energetic heavy projectiles of several hundred MeV introducing so-called "latent tracks" Subsequently, the film in a rubber elastic state is formed into three dimensional parts without modifying or annealing the tracks. After the forming process, selective chemical etching finally converts the tracks into cylindrical pores of adjustable diameter.

We present two processes for the microfabrication of porous polymer chips for three-dimensional cell cultivation. The first one is hot embossing combined with a solvent vapour welding process. The second one uses a recently developed microthermoforming process combined with ion track technology leading to a significant simplification of manufacture.

التصنيع الدقيق للرقاقة الحجم السقالات لزراعة الخلايا ثلاثي الأبعاد

Using microfabrication technologies is a prerequisite to create scaffolds of reproducible geometry and constant quality for three-dimensional cell ...

Two-photon axotomy and time-lapse confocal imaging in live zebrafish embryos

Zebrafish have long been utilized to study the cellular and molecular mechanisms of development by time-lapse imaging of the living transparent embryo. Here we describe a method to mount zebrafish embryos for long-term imaging and demonstrate how to automate the capture of time-lapse images using a confocal microscope. We also describe a method to create controlled, precise damage to individual branches of peripheral sensory axons in zebrafish using the focused power of a femtosecond laser mounted on a two-photon microscope. The parameters for successful two-photon axotomy must be optimized for each microscope. We will demonstrate two-photon axotomy on both a custom built two-photon microscope and a Zeiss 510 confocal/two-photon to provide two examples.

Zebrafish trigeminal sensory neurons can be visualized in a transgenic line expressing GFP driven by a sensory neuron specific promoter 1. We have adapted this zebrafish trigeminal model to directly observe sensory axon regeneration in living zebrafish embryos. Embryos are anesthetized with tricaine and positioned within a drop of agarose as it solidifies. Immobilized embryos are sealed within an imaging chamber filled with phenylthiourea (PTU) Ringers. We have found that embryos can be continuously imaged in these chambers for 12-48 hours. A single confocal image is then captured to determine the desired site of axotomy. The region of interest is located on the two-photon microscope by imaging the sensory axons under low, non-damaging power. After zooming in on the desired site of axotomy, the power is increased and a single scan of that defined region is sufficient to sever the axon. Multiple location time-lapse imaging is then set up on a confocal microscope to directly observe axonal recovery from injury.

Here we describe a method for mounting zebrafish embryos for long-term imaging, two-photon imaging and tissue-damage techniques, and time-lapse confocal imaging.

ثنائي الفوتون axotomy والوقت الفاصل بين التصوير مبائر يعيش في الأجنة الزرد

Zebrafish have long been utilized to study the cellular and molecular mechanisms of development by time-lapse imaging of the living transparent embryo.  ...

Fluorescent Labeling of COS-7 Expressing SNAP-tag Fusion Proteins for Live Cell Imaging

SNAP-tag and CLIP-tag protein labeling systems enable the specific, covalent attachment of molecules, including fluorescent dyes, to a protein of interest in live cells. These systems offer a broad selection of fluorescent substrates optimized for a range of imaging instrumentation. Once cloned and expressed, the tagged protein can be used with a variety of substrates for numerous downstream applications without having to clone again. There are two steps to using this system: cloning and expression of the protein of interest as a SNAP-tag fusion, and labeling of the fusion with the SNAP-tag substrate of choice. The SNAP-tag is a small protein based on human O6-alkylguanine-DNA-alkyltransferase (hAGT), a DNA repair protein. SNAP-tag labels are dyes conjugated to guanine or chloropyrimidine leaving groups via a benzyl linker. In the labeling reaction, the substituted benzyl group of the substrate is covalently attached to the SNAP-tag. CLIP-tag is a modified version of SNAP-tag, engineered to react with benzylcytosine rather than benzylguanine derivatives. When used in conjunction with SNAP-tag, CLIP-tag enables the orthogonal and complementary labeling of two proteins simultaneously in the same cells.

SNAP-tag and CLIP-tag protein labeling systems enable the specific, covalent attachment of molecules, including fluorescent dyes, to a protein of interest in live cells. Once cloned and expressed, the tagged protein can be used with a variety of substrates for numerous downstream applications without having to clone again.

الفلورسنت وصفها من COS - 7 تعرب عن البروتينات الانصهار SNAP - شعارا لتصوير الخلايا الحية

SNAP-tag and CLIP-tag protein labeling systems enable the specific, covalent attachment of molecules, including fluorescent dyes, to a protein of interest ...

Two-Photon-Based Photoactivation in Live Zebrafish Embryos

Photoactivation of target compounds in a living organism has proven a valuable approach to investigate various biological processes such as embryonic development, cellular signaling and adult physiology. In this respect, the use of multi-photon microscopy enables quantitative photoactivation of a given light responsive agent in deep tissues at a single cell resolution. As zebrafish embryos are optically transparent, their development can be monitored in vivo. These traits make the zebrafish a perfect model organism for controlling the activity of a variety of chemical agents and proteins by focused light. Here we describe the use of two-photon microscopy to induce the activation of chemically caged fluorescein, which in turn allows us to follow cell's destiny in live zebrafish embryos. We use embryos expressing a live genetic landmark (GFP) to locate and precisely target any cells of interest. This procedure can be similarly used for precise light induced activation of proteins, hormones, small molecules and other caged compounds.

Multiphoton microscopy allows control of low energy photons with deep optical penetration and reduced phototoxicity. We describe the use of this technology for live cell labeling in zebrafish embryos. This protocol can be readily adapted for photo-induction of various light-responsive molecules.

ثنائي الفوتون المستندة إلى تنشيط ضوئي في الأجنة الحية اسماك الزرد

Photoactivation of target compounds in a living organism has proven a valuable approach to investigate various biological processes such as embryonic ...

Live Imaging of GFP-labeled Proteins in Drosophila Oocytes

The Drosophila oocyte has been established as a versatile system for investigating fundamental questions such as cytoskeletal function, cell organization, and organelle structure and function. The availability of various GFP-tagged proteins means that many cellular processes can be monitored in living cells over the course of minutes or hours, and using this technique, processes such as RNP transport, epithelial morphogenesis, and tissue remodeling have been described in great detail in Drosophila oocytes1,2.
The ability to perform video imaging combined with a rich repertoire of mutants allows an enormous variety of genes and processes to be examined in incredible detail. One such example is the process of ooplasmic streaming, which initiates at mid-oogenesis3,4. This vigorous movement of cytoplasmic vesicles is microtubule and kinesin-dependent5 and provides a useful system for investigating cytoskeleton function at these stages.
Here I present a protocol for time lapse imaging of living oocytes using virtually any confocal microscopy setup.

Live Imaging of GFP-labeled Proteins in Drosophila Oocytes

A protocol for live imaging of GFP-tagged proteins or autofluorescent structures in individual Drosophila oocytes is described.

يعيش التصوير من البروتينات التي تحمل علامات GFP في<em&gt; ذبابة الفاكهة</em&gt; البويضات

The  Drosophila oocyte has been established as a versatile system for investigating  fundamental questions such as cytoskeletal function, cell ...

Mouse Fetal Whole Intestine Culture System for Ex Vivo Manipulation of Signaling Pathways and Three-dimensional Live Imaging of Villus Development

Most morphogenetic processes in the fetal intestine have been inferred from thin sections of fixed tissues, providing snapshots of changes over developmental stages. Three-dimensional information from thin serial sections can be challenging to interpret because of the difficulty of reconstructing serial sections perfectly and maintaining proper orientation of the tissue over serial sections. Recent findings by Grosse et al., 2011 highlight the importance of three- dimensional information in understanding morphogenesis of the developing villi of the intestine1. Three-dimensional reconstruction of singly labeled intestinal cells demonstrated that the majority of the intestinal epithelial cells contact both the apical and basal surfaces. Furthermore, three-dimensional reconstruction of the actin cytoskeleton at the apical surface of the epithelium demonstrated that the intestinal lumen is continuous and that secondary lumens are an artifact of sectioning. Those two points, along with the demonstration of interkinetic nuclear migration in the intestinal epithelium, defined the developing intestinal epithelium as a pseudostratified epithelium and not stratified as previously thought1. The ability to observe the epithelium three-dimensionally was seminal to demonstrating this point and redefining epithelial morphogenesis in the fetal intestine. With the evolution of multi-photon imaging technology and three-dimensional reconstruction software, the ability to visualize intact, developing organs is rapidly improving. Two-photon excitation allows less damaging penetration deeper into tissues with high resolution. Two-photon imaging and 3D reconstruction of the whole fetal mouse intestines in Walton et al., 2012 helped to define the pattern of villus outgrowth2. Here we describe a whole organ culture system that allows ex vivo development of villi and extensions of that culture system to allow the intestines to be three-dimensionally imaged during their development.

Mouse Fetal Whole Intestine Culture System for Ex Vivo Manipulation of Signaling Pathways and Three-dimensional Live Imaging of Villus Development

Improved imaging technology is allowing three-dimensional imaging of organs during development. Here we describe a whole organ culture system that allows live imaging of the developing villi in the fetal mouse intestine.

نظام الثقافة الماوس الجنين الأمعاء الجامعة ل<em&gt; فيفو السابقين</em&gt; التلاعب في مسارات إشارات وتصوير لايف ثلاثي الأبعاد التنمية الزغبة

Most morphogenetic processes in the fetal intestine have been inferred from thin sections of fixed tissues, providing snapshots of changes over ...

FRET Imaging in Three-dimensional Hydrogels

Imaging of F&#246;rster resonance energy transfer (FRET)&#160;is a powerful tool for examining cell biology in real-time. Studies utilizing FRET commonly employ two-dimensional (2D) culture, which does not mimic the three-dimensional (3D) cellular microenvironment. A method to perform quenched emission FRET imaging using conventional widefield epifluorescence microscopy of cells within a 3D hydrogel environment is presented. Here an analysis method for ratiometric FRET probes that yields linear ratios over the probe activation range is described. Measurement of intracellular cyclic adenosine monophosphate (cAMP) levels is demonstrated in chondrocytes under forskolin stimulation using a probe for EPAC1 activation (ICUE1) and the ability to detect differences in cAMP signaling dependent on hydrogel material type, herein a photocrosslinking hydrogel (PC-gel, polyethylene glycol dimethacrylate) and a thermoresponsive hydrogel (TR-gel). Compared with 2D FRET methods, this method requires little additional work. Laboratories already utilizing FRET imaging in 2D can easily adopt this method to perform cellular studies in a 3D microenvironment. It can further be applied to high throughput drug screening in engineered 3D microtissues. Additionally, it is compatible with other forms of FRET imaging, such as anisotropy measurement and fluorescence lifetime imaging (FLIM), and with advanced microscopy platforms using confocal, pulsed, or modulated illumination.

F&#246;rster resonance energy transfer (FRET) imaging is a powerful tool for real-time cell biology studies. Here a method for FRET imaging cells in physiologic three-dimensional (3D) hydrogel microenvironments using conventional epifluorescence microscopy is presented. An analysis for ratiometric FRET probes that yields linear ratios over the activation range is described.

الحنق التصوير في الهلاميات المائية ثلاثية الأبعاد

Imaging of F&#246;rster resonance energy transfer (FRET)&#160;is a powerful tool for examining cell biology in real-time. Studies utilizing FRET commonly ...

Single-Cell Resolution Three-Dimensional Imaging of Intact Organoids

Organoid technology, in vitro 3D culturing of miniature tissue, has opened a new experimental window for cellular processes that govern organ development and function as well as disease. Fluorescence microscopy has played a major role in characterizing their cellular composition in detail and demonstrating their similarity to the tissue they originate from. In this article, we present a comprehensive protocol for high-resolution 3D imaging of whole organoids upon immunofluorescent labeling. This method is widely applicable for imaging of organoids differing in origin, size and shape. Thus far we have applied the method to airway, colon, kidney, and liver organoids derived from healthy human tissue, as well as human breast tumor organoids and mouse mammary gland organoids. We use an optical clearing agent, FUnGI, which enables the acquisition of whole 3D organoids with the opportunity for single-cell quantification of markers. This three-day protocol from organoid harvesting to image analysis is optimized for 3D imaging using confocal microscopy.

The entire 3D structure and cellular content of organoids, as well as their phenotypic resemblance to the original tissue can be captured using the single-cell resolution 3D imaging protocol described here. This protocol can be applied to a wide range of organoids varying in origin, size and shape.

وحيد الخلية القرار التصوير ثلاثي الأبعاد من organoids سليمة

Organoid technology, in vitro 3D culturing of miniature tissue, has opened a new experimental window for cellular processes that govern organ development ...

Staining and High-Resolution Imaging of Three-Dimensional Organoid and Spheroid Models

In vitro three-dimensional (3D) cell culture models, such as organoids and spheroids, are valuable tools for many applications including development and disease modeling, drug discovery, and regenerative medicine. To fully exploit these models, it is crucial to study them at cellular and subcellular levels. However, characterizing such in vitro 3D cell culture models can be technically challenging and requires specific expertise to perform effective analyses. Here, this paper provides detailed, robust, and complementary protocols to perform staining and subcellular resolution imaging of fixed in vitro 3D cell culture models ranging from 100 &#181;m to several millimeters. These protocols are applicable to a wide variety of organoids and spheroids that differ in their cell-of-origin, morphology, and culture conditions. From 3D structure harvesting to image analysis, these protocols can be completed within 4-5 days. Briefly, 3D structures are collected, fixed, and can then be processed either through paraffin-embedding and histological/immunohistochemical staining, or directly immunolabeled and prepared for optical clearing and 3D reconstruction (200 &#181;m depth) by confocal microscopy.

Here, we provide detailed, robust, and complementary protocols to perform staining and subcellular resolution imaging of fixed three-dimensional cell culture models ranging from 100 &#181;m to several millimeters, thus enabling the visualization of their morphology, cell-type composition, and interactions.

تلطيخ وتصوير عالي الدقة لنماذج عضوية وكروية ثلاثية الأبعاد

In vitro three-dimensional (3D) cell culture models, such as organoids and spheroids, are valuable tools for many applications including development and ...

Live-Cell Imaging of Transcriptional Activity at DNA Double-Strand Breaks

DNA double-strand breaks (DSB) are the most severe type of DNA damage. Despite the catastrophic consequences on genome integrity, it remains so far elusive how DSBs affect transcription. A reason for this was the lack of suitable tools to simultaneously monitor transcription and the induction of a genic DSB with sufficient temporal and spatial resolution. This work describes a set of new reporters that directly visualize transcription in live cells immediately after the induction of a DSB in the DNA template. Bacteriophage RNA stem-loops are employed to monitor the transcription with single-molecule sensitivity. For targetting the DSB to a specific gene region, the reporter genes are engineered to contain a single recognition sequence of the homing endonuclease I-SceI, otherwise absent from the human genome. A single copy of each reporter gene was integrated into the genome of human cell lines. This experimental system allows the detection of single RNA molecules generated by the canonical gene transcription or by DNA break-induced transcription initiation. These reporters provide an unprecedented opportunity for interpreting the reciprocal interactions between transcription and DNA damage and to disclose hitherto unappreciated aspects of DNA break-induced transcription.

This protocol presents a new reporter gene system and the experimental setup to detect transcription at DNA double-strand breaks with single-molecule sensitivity.

تصوير الخلايا الحية للنشاط النسخي في فواصل الحمض النووي مزدوجة ستراند

DNA double-strand breaks (DSB) are the most severe type of DNA damage. Despite the catastrophic consequences on genome integrity, it remains so far ...