نشكر اندرو كارول ، Chaibang برايت ، Purbasha ساركار (الطاقة الحيوية للعلوم معهد بيركلي) ، بهرام بارفين (مختبر لورانس بيركلي الوطني) وتشيانغ فنسنت لام (ولاية كارولينا الشمالية جامعة) للتعاون المثمر ومناقشات مفيدة. وأيد هذا العمل من قبل معهد العلوم البيولوجية الطاقة. وأيد العمل في مسبك الجزيئية من مكتب العلوم ومكتب للعلوم الأساسية للطاقة ، وزارة الطاقة في الولايات المتحدة بموجب العقد رقم DE - AC02 - 05CH1123.

1. تحضير العينة <ol style=";text-align:right;direction:rtl"><li style=";text-align:right;direction:rtl"> جبل العينة النباتية المائية ، مثل الخشب أو جذع شجرة الحور Arabidopsis thaliana الجذعية ، في مشراح. </li><li style=";text-align:right;direction:rtl"> خفض الشرائح الرقيقة (عادة 20 ميكرون سميكة) من النسيج الأصلي. </li><li style=";text-align:right;direction:rtl"> نقل قسم النبات على شريحة ميكروسكوب زجاجية. </li><li style=";text-align:right;direction:rtl"> نقع قسم النبات في D 2 O ، وتغطي مع كوب زلة تغطية ، وهي مختومة على الشريحة مجهر لمنع تبخر D 2 O. قسم النبات هو الآن جاهز للتصوير أو يمكن تخزينها لاستخدامها في المستقبل. </li></ol> 2. نموذج القياس <ol style=";text-align:right;direction:rtl"><li style=";text-align:right;direction:rtl"> تطبيق زيت الغمر في تحقيق الهدف المجهر و / أو زلة غطاء. </li><li style=";text-align:right;direction:rtl"> مكان وتأمين شريحة مجهر المسح على المسرح كهرضغطية من المجهر ، مع انزلاق الغطاء تواجه الهدف المجهر. </li><li style=";text-align:right;direction:rtl"> عرض عينة من خلال زلة تغطية عالية باستخدام الغمر الفتحة العددية الهدف المجهر (100X ، NA = 1.40) ، وتحديد منطقة عينة من الفائدة. </li><li style=";text-align:right;direction:rtl"> يتم إجراء قياسات microspectroscopic بعد إيقاف جميع ضوء المختبرية وغيرها من مصادر المجهر ، والموقف ، من خلال التركيز حل ممر الموجة مفلتر الضوء الاخضر أحادي اللون (λ = 532 نانومتر) من CW - بالليزر على عينة نموذجية مع قوة من 10 إلى 30 ميغاواط ( انظر الشكل رقم 1 لالتخطيطي من الإعداد). تألق ذاتي يمكن أن يحدث في بعض العينات ، والتي قد تمنع قياسات مفيدة ، والذي يعد إثارة القضية مع ضوء الليزر الطول الموجي قد يكون من المستحسن. </li><li style=";text-align:right;direction:rtl"> يتم جمع متناثرة الضوء الخلفي رامان ستوكس التي تحول الهدف المجهر ، يمر من خلال مرآة مزدوج اللون ، وذات الثقب ، والتي هي بمثابة تصفية المكانية في الإعداد مبائر ، وتصفية longpass ، ويركز في الشق من صريف مطياف ، حيث فرقت طيفيا الضوء والكشف عنها بواسطة كاميرا CCD تبريده ، وإعطاء الطيف رامان. ويرد الطيف رامان من خشب الحور في الشكل 2 ، مع العصابات اللجنين مميزة في المنطقة الطيفية بين 1600 و 1700 سم -1. </li><li style=";text-align:right;direction:rtl"> التصوير الكيميائية والتصور للتوزيع المكاني اللجنين ، وحصلت على خريطة ثنائية الأبعاد الطيفي بواسطة النقطية مسح العينة من خلال التركيز الليزر مع مرحلة فحص وتسجيل كهرضغطية طائفة رامان لكل موقف العينة. قد يكون إنشاء خرائط ثلاثية الأبعاد الطيفي بواسطة التراص ثنائي الأبعاد لخرائط التي كانت كثفت التركيز على التوالي ليزر على طول ض الاتجاه. </li></ol> 3. تحليل البيانات <ol style=";text-align:right;direction:rtl"><li style=";text-align:right;direction:rtl"> التصوير الكيميائية والتصور اللجنين ، ويتم تحليل البيانات التي تم جمعها باستخدام MATLAB (MathWorks ، الإصدار 7.7). يتم ترتيب البيانات في مكعب ثلاثي الأبعاد الفائقة الطيفية ، التي تتألف من البعدين المكاني والبعد الثالث للإشارات الطيفية. </li><li style=";text-align:right;direction:rtl"> لتحليل اللجنين ، تعتبر المنطقة الطيفية بين 1550 و 1700 سم -1 (انظر الشكل 2). التوزيع المكاني للاللجنين هو تصور من خلال دمج كثافة من 1550 إلى 1700 سم -1 من الأطياف الأساس لتصحيح (انظر الشكل 3). كبديل للتصويب خط الأساس ، يمكن حسابها الثاني مشتق الأطياف والقمم الثاني مشتق تستخدم للتحليل. </li><li style=";text-align:right;direction:rtl"> قد تكون اللجنين التعريب والكيمياء ، وخاصة فيما يتعلق coniferaldehyde والأنصاف coniferyl الكحول ، لمزيد من التحليل من خلال تقييم المنطقة تحت قمم غاوسي تركيبها من المجموعات الثلاث وجدت بين 1600 و 1700 سم -1 (انظر الشكل رقم 2 من أقحم والحكام 15 -- 17). </li><li style=";text-align:right;direction:rtl"> يتم تنفيذ التطبيع بين الكثافة الطيفية المختلفة باستخدام الخرائط كمرجع ذروة الذروة من الفرقة OD خارجي يمتد حوالي 2500 سم -1 في أطياف التجويف المتوسط ​​، والتي حصلت عليها ك يعني تصنيف المجموعات. هذا أمر بالغ الأهمية ، ويسمح احد لشدة مقارنة إشارة اللجنين بين القياسات المختلفة والأنسجة ، وعينات والأنواع. </li></ol> 4. ممثل النتائج ويرد ممثل الطيف رامان من خشب الحور الجذعية (حور angustifolia) في الشكل رقم 2. تم العثور على نطاقات اللجنين مميزة في المنطقة الطيفية بين 1600 و 1700 سم -1. كمثال على ذلك ، يتم تقديم التوزيع المكاني للاللجنين في شريحة خشب الحور في الشكل 3. مقارنة لصورة مرئية ، شكليا مناطق متميزة جدار الخلية تصبح تمييزها بوضوح بسبب كثافة مختلفة اللجنين الإشارة. ويلاحظ ارتفاع الكثافة إشارة اللجنين في زوايا الخلية (CC) ، وإلى حد ما أقل ، في مجمع صفاحات المتوسطة (CML). ولوحظت كميات أقل ، ولكن لا يستهان بها ، من اللجنين داخل الجدار S2 طبقة من الألياف. تم العثور على تباين كثافة اللجنين إشارة إلى حد ما داخل CC ، CML وS2 ، وخاصة من الألياف إلى الألياف. القرار المكانية الوحشي في القياسات لدينا ~ 300 نانومتر. جودة البيانات يفسح المجال بشكل جيد للمقارنة بين lignificationعينات وكذلك تشريح اللجنين الكيمياء 15. <img src="/files/ftp_upload/2064/2064fig1.jpg" alt="الشكل 1" /> الشكل 1 : والتخطيطي للإعداد أداة BP : ممر الموجة مرشح ؛ DM : مرآة مزدوج اللون ، ودرجة الحموضة : الثقب ؛ ليرة لبنانية : longpass التصفية. <img src="/files/ftp_upload/2064/2064fig2.jpg" alt="الشكل 2" /> الرقم 2 : طيف ممثل من خشب الحور رامان الجذعية (حور angustifolia) التي سجلت في D 2 O. منطقة الضوء الطيفي (انظر أيضا أقحم) علامات المنطقة الطيفية وجود ثلاث قمم تعزى على وجه التحديد إلى اللجنين. <img src="/files/ftp_upload/2064/2064fig3.jpg" alt="الشكل 3" /> الشكل 3 : رامان اللجنين الصورة (أسفل) من شريحة خشب الحور (أعلى : صورة مرئية) ، التي تم الحصول عليها من خلال دمج كثافة إشارة رامان من 1550 إلى 1700 سم -1.

<ol>
	<li>Herrera, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bonkers+about+biofuels.">Bonkers about biofuels.</a> Nat Biotechnol. 24, 755-760 (2006).</li><li>Himmel, M. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biomass+recalcitrance:+Engineering+plants+and+enzymes+for+biofuels+production.">Biomass recalcitrance: Engineering plants and enzymes for biofuels production.</a> Science. 315, 804-807 (2007).</li><li>Pauly, M., Keegstra, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell-wall+carbohydrates+and+their+modification+as+a+resource+for+biofuels.">Cell-wall carbohydrates and their modification as a resource for biofuels.</a> Plant J. 54, 559-568 (2008).</li><li>Pauly, M., Keegstra, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Physiology+and+metabolism+'Tear+down+this+wall.">Physiology and metabolism 'Tear down this wall.</a> Curr Opin Plant Biol. 11, 233-235 (2008).</li><li>Ragauskas, A. 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+path+forward+for+biofuels+and+biomaterials.">The path forward for biofuels and biomaterials.</a> Science. 311, 484-489 (2006).</li><li>Somerville, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biofuels.">Biofuels.</a> Curr Biol. 17, R115-R119 (2007).</li><li>Ralph, J., Brunow, G., Boerjan, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Lignins in Encyclopedia of Life Sciences. , (2007).</li><li>Chiang, V. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=From+rags+to+riches.">From rags to riches.</a> Nat Biotechnol. 20, 557-558 (2002).</li><li>Atalla, R. 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P., Argyropoulos, D. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+Overview+of+Raman+Spectroscopy+as+Applied+to+Lignocellulosic+Materials.">An Overview of Raman Spectroscopy as Applied to Lignocellulosic Materials.</a> Advances in Lignocellulosics Characterization. , 201-225 (1999).</li><li>Agarwal, U. P., Ralph, S. 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الإعلان عن أي تضارب في المصالح.

هي مواد Lignocellulosic الهرمي وغير متجانسة فيما يتعلق بكل من هيكلها وتكوينها. لتوصيف الأدوات التحليلية المتعمقة التي الحساسية الكيميائية ، القرار المكانية ، والتي تعطي نظرة ثاقبة هذه المواد في سياق الأم ومرغوب فيه. وصف الأسلوب يتيح للتصور اللجنين ومقارنة lignification من الكتل?...

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label-free in situ imaging of lignification in plant cell walls

Meeting growing energy demands safely and efficiently is a pressing global challenge. Therefore, research into biofuels production that seeks to find cost-effective and sustainable solutions has become a topical and critical task. Lignocellulosic biomass is poised to become the primary source of biomass for the conversion to liquid biofuels1-6. However, the recalcitrance of these plant cell wall materials to cost-effective and efficient degradation presents a major impediment for their use in the production of biofuels and chemicals4. In particular, lignin, a complex and irregular poly-phenylpropanoid heteropolymer, becomes problematic to the postharvest deconstruction of lignocellulosic biomass. For example in biomass conversion for biofuels, it inhibits saccharification in processes aimed at producing simple sugars for fermentation7. The effective use of plant biomass for industrial purposes is in fact largely dependent on the extent to which the plant cell wall is lignified. The removal of lignin is a costly and limiting factor8 and lignin has therefore become a key plant breeding and genetic engineering target in order to improve cell wall conversion.
Analytical tools that permit the accurate rapid characterization of lignification of plant cell walls become increasingly important for evaluating a large number of breeding populations. Extractive procedures for the isolation of native components such as lignin are inevitably destructive, bringing about significant chemical and structural modifications9-11. Analytical chemical in situ methods are thus invaluable tools for the compositional and structural characterization of lignocellulosic materials. Raman microscopy is a technique that relies on inelastic or Raman scattering of monochromatic light, like that from a laser, where the shift in energy of the laser photons is related to molecular vibrations and presents an intrinsic label-free molecular "fingerprint" of the sample. Raman microscopy can afford non-destructive and comparatively inexpensive measurements with minimal sample preparation, giving insights into chemical composition and molecular structure in a close to native state. Chemical imaging by confocal Raman microscopy has been previously used for the visualization of the spatial distribution of cellulose and lignin in wood cell walls12-14. Based on these earlier results, we have recently adopted this method to compare lignification in wild type and lignin-deficient transgenic Populus trichocarpa (black cottonwood) stem wood15. Analyzing the lignin Raman bands16,17 in the spectral region between 1,600 and 1,700 cm-1, lignin signal intensity and localization were mapped in situ. Our approach visualized differences in lignin content, localization, and chemical composition. Most recently, we demonstrated Raman imaging of cell wall polymers in Arabidopsis thaliana with lateral resolution that is sub-&mu;m18. Here, this method is presented affording visualization of lignin in plant cell walls and comparison of lignification in different tissues, samples or species without staining or labeling of the tissues.

Watch this Scientific Journal Video about Label-free in situ Imaging of Lignification in Plant Cell Walls at JoVE.com

Label-free in situ Imaging of Lignification in Plant Cell Walls

ويرد على أساس أسلوب رامان المجهري متحد البؤر التي تتيح تسمية خالية من التصور اللجنين في جدران الخلايا النباتية ومقارنة lignification في الأنسجة المختلفة ، وعينات أو الأنواع.

التسمية خالية في الموقع تصوير Lignification في جدران الخلايا النباتية

Meeting growing energy demands safely and efficiently is a pressing global challenge. Therefore, research into biofuels production that seeks to find ...

label-free-in-situ-imaging-of-lignification-in-plant-cell-walls

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JoVE Journal

Biology

Label-free in situ Imaging of Lignification in Plant Cell Walls

12.3K Views.  University of California, Berkeley. ويرد على أساس أسلوب رامان المجهري متحد البؤر التي تتيح تسمية خالية من التصور اللجنين في جدران الخلايا النباتية ومقارنة lignification في الأنسجة المختلفة ، وعينات أو الأنواع.

Video: Label-free in situ Imaging of Lignification in Plant Cell Walls

In situ Imaging of the Mouse Thymus Using 2-Photon Microscopy

Two-photon Microscopy (TPM) enables us to image deep into the thymus and document the events that are important for thymocyte development. To follow the migration of individuals in a crowd of thymocytes , we generate neonatal chimeras where less than one percent of the thymocytes are derived from a donor that is transgenic for a ubiquitously express fluorescent protein. To generate these partial hematopoetic chimeras, neonatal recipients are injected with bone marrow between 3-7 days of age. After 4-6 weeks, the mouse is sacrificed and the thymus is carefully dissected and bissected preserving the architecture of the tissue that will be imaged. The thymus is glued onto a coverslip in preparation for ex vivo imaging by TPM. During imaging the thymus is kept in DMEM without phenol red that is perfused with 95% oxygen and 5% carbon dioxide and warmed to 37&deg;C. Using this approach, we can study the events required for the generation of a diverse T cell repertoire.

We present step-by-step instructions for the generation of neonatal chimeras as well as the dissection and preparation of the thymus for ex vivo imaging by 2-Photon Microscopy.

التصوير في الموقع من الغدة الصعترية ماوس باستخدام الميكروسكوب 2 فوتون

Two-photon Microscopy (TPM) enables us to image deep into the thymus and document the events that are important for thymocyte development.  To follow the ...

Comprehensive Compositional Analysis of Plant Cell Walls (Lignocellulosic biomass) Part I: Lignin

The need for renewable, carbon neutral, and sustainable raw materials for industry and society has become one of the most pressing issues for the 21st century. This has rekindled interest in the use of plant products as industrial raw materials for the production of liquid fuels for transportation1 and other products such as biocomposite materials7. Plant biomass remains one of the greatest untapped reserves on the planet4. It is mostly comprised of cell walls that are composed of energy rich polymers including cellulose, various hemicelluloses (matrix polysaccharides, and the polyphenol lignin6 and thus sometimes termed lignocellulosics. However, plant cell walls have evolved to be recalcitrant to degradation as walls provide tensile strength to cells and the entire plants, ward off pathogens, and allow water to be transported throughout the plant; in the case of trees up to more the 100 m above ground level. Due to the various functions of walls, there is an immense structural diversity within the walls of different plant species and cell types within a single plant4. Hence, depending of what crop species, crop variety, or plant tissue is used for a biorefinery, the processing steps for depolymerization by chemical/enzymatic processes and subsequent fermentation of the various sugars to liquid biofuels need to be adjusted and optimized. This fact underpins the need for a thorough characterization of plant biomass feedstocks. Here we describe a comprehensive analytical methodology that enables the determination of the composition of lignocellulosics and is amenable to a medium to high-throughput analysis. In this first part we focus on the analysis of the polyphenol lignin (Figure 1). The method starts of with preparing destarched cell wall material. The resulting lignocellulosics are then split up to determine its lignin content by acetylbromide solubilization3, and its lignin composition in terms of its syringyl, guaiacyl- and p-hydroxyphenyl units5. The protocol for analyzing the carbohydrates in lignocellulosic biomass including cellulose content and matrix polysaccharide composition is discussed in Part II2.

Comprehensive Compositional Analysis of Plant Cell Walls Lignocellulosic biomass Part I: Lignin

Plant biomass is a major carbon-neutral renewable resource that could be used for the production of biofuels. Plant biomass consists mainly of cell walls, a structurally complex composite material termed lignocellulosics. Here we describe a protocol for a comprehensive analysis of the content and composition of the polyphenolic lignin.

تحليل شامل للالتركيبية جدران الخلايا النباتية (الكتلة الحيوية Lignocellulosic) الجزء الأول : اللجنين

The need for renewable, carbon neutral, and sustainable raw materials for industry and society has become one of the most pressing issues for the 21st ...

Comprehensive Compositional Analysis of Plant Cell Walls (Lignocellulosic biomass) Part II: Carbohydrates

The need for renewable, carbon neutral, and sustainable raw materials for industry and society has become one of the most pressing issues for the 21st century. This has rekindled interest in the use of plant products as industrial raw materials for the production of liquid fuels for transportation2 and other products such as biocomposite materials6. Plant biomass remains one of the greatest untapped reserves on the planet4. It is mostly comprised of cell walls that are composed of energy rich polymers including cellulose, various hemicelluloses, and the polyphenol lignin5 and thus sometimes termed lignocellulosics. However, plant cell walls have evolved to be recalcitrant to degradation as walls contribute extensively to the strength and structural integrity of the entire plant. Despite its necessary rigidity, the cell wall is a highly dynamic entity that is metabolically active and plays crucial roles in numerous cell activities such as plant growth and differentiation5. Due to the various functions of walls, there is an immense structural diversity within the walls of different plant species and cell types within a single plant4. Hence, depending of what crop species, crop variety, or plant tissue is used for a biorefinery, the processing steps for depolymerisation by chemical/enzymatic processes and subsequent fermentation of the various sugars to liquid biofuels need to be adjusted and optimized. This fact underpins the need for a thorough characterization of plant biomass feedstocks. Here we describe a comprehensive analytical methodology that enables the determination of the composition of lignocellulosics and is amenable to a medium to high-throughput analysis (Figure 1). The method starts of with preparing destarched cell wall material. The resulting lignocellulosics are then split up to determine its monosaccharide composition of the hemicelluloses and other matrix polysaccharides1, and its content of crystalline cellulose7. The protocol for analyzing the lignin components in lignocellulosic biomass is discussed in Part I3.

Comprehensive Compositional Analysis of Plant Cell Walls Lignocellulosic biomass Part II: Carbohydrates

Plant biomass is a major carbon-neutral renewable resource that could be used for the production of biofuels. Plant biomass consists mainly of cell walls, a structurally complex composite material termed lignocellulosics. Here we describe a protocol for a comprehensive analysis of the content and composition of wall derived carbohydrates.

التركيبية تحليل شامل لجدران الخلايا النباتية (الكتلة الحيوية Lignocellulosic) الجزء الثاني : الكربوهيدرات

In situ Quantification of Pancreatic Beta-cell Mass in Mice

Tracing changes of specific cell populations in health and disease is an important goal of biomedical research. The process of monitoring pancreatic beta-cell proliferation and islet growth is particularly challenging. We have developed a method to capture the distribution of beta-cells in the intact pancreas of transgenic mice with fluorescence-tagged beta-cells with a macro written for ImageJ (rsb.info.nih.gov/ij/). Following pancreatic dissection and tissue clearing, the entire pancreas is captured as a virtual slice, after which the GFP-tagged beta-cells are examined. The analysis includes the quantification of total beta-cell area, islet number and size distribution with reference to specific parameters and locations for each islet and for small clusters of beta-cells. The entire distribution of islets can be plotted in three dimensions, and the information from the distribution on the size and shape of each islet allows a quantitative and qualitative comparison of changes in overall beta-cell area at a glance.

In situ Quantification of Pancreatic Beta-cell Mass in Mice

The following protocol outlines the process of pancreatic dissection for virtual slice imaging, and the subsequent quantification of all GFP-tagged beta-cells in the entire pancreas.

في الوضع الطبيعي للقداس الكمي بيتا في البنكرياس خلايا الفئران

Tracing changes of specific cell populations in health and disease is an important goal of biomedical research. The process of monitoring pancreatic ...

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 ...

Glycan Profiling of Plant Cell Wall Polymers using Microarrays

Plant cell walls are complex matrixes of heterogeneous glycans which play an important role in the physiology and development of plants and provide the raw materials for human societies (e.g. wood, paper, textile and biofuel industries)1,2. However, understanding the biosynthesis and function of these components remains challenging.
Cell wall glycans are chemically and conformationally diverse due to the complexity of their building blocks, the glycosyl residues. These form linkages at multiple positions and differ in ring structure, isomeric or anomeric configuration, and in addition, are substituted with an array of non-sugar residues. Glycan composition varies in different cell and/or tissue types or even sub-domains of a single cell wall3. Furthermore, their composition is also modified during development1, or in response to environmental cues4.
In excess of 2,000 genes have Plant cell walls are complex matrixes of heterogeneous glycans been predicted to be involved in cell wall glycan biosynthesis and modification in Arabidopsis5. However, relatively few of the biosynthetic genes have been functionally characterized 4,5. Reverse genetics approaches are difficult because the genes are often differentially expressed, often at low levels, between cell types6. Also, mutant studies are often hindered by gene redundancy or compensatory mechanisms to ensure appropriate cell wall function is maintained7. Thus novel approaches are needed to rapidly characterise the diverse range of glycan structures and to facilitate functional genomics approaches to understanding cell wall biosynthesis and modification.
Monoclonal antibodies (mAbs)8,9 have emerged as an important tool for determining glycan structure and distribution in plants. These recognise distinct epitopes present within major classes of plant cell wall glycans, including pectins, xyloglucans, xylans, mannans, glucans and arabinogalactans. Recently their use has been extended to large-scale screening experiments to determine the relative abundance of glycans in a broad range of plant and tissue types simultaneously9,10,11.
Here we present a microarray-based glycan screening method called Comprehensive Microarray Polymer Profiling (CoMPP) (Figures 1 &amp; 2)10,11 that enables multiple samples (100 sec) to be screened using a miniaturised microarray platform with reduced reagent and sample volumes. The spot signals on the microarray can be formally quantified to give semi-quantitative data about glycan epitope occurrence. This approach is well suited to tracking glycan changes in complex biological systems12 and providing a global overview of cell wall composition particularly when prior knowledge of this is unavailable.

A technique called Comprehensive Microarray Polymer Profiling (CoMPP) for the characterisation of plant cell wall glycans is described. This method combines the specificity of monoclonal antibodies directed to defined glycan-epitopes with a miniature microarray analytical platform allowing screening of glycan occurrence in a broad range of biological contexts.

غليكان التنميط من البوليمرات جدار الخلية النباتية باستخدام [ميكروأرس]

Plant cell walls are complex matrixes of heterogeneous glycans which play an important role in the physiology and development of plants and provide the ...

Live Imaging of Apoptotic Cell Clearance during Drosophila Embryogenesis

The proper elimination of unwanted or aberrant cells through apoptosis and subsequent phagocytosis (apoptotic cell clearance) is crucial for normal development in all metazoan organisms. Apoptotic cell clearance is a highly dynamic process intimately associated with cell death; unengulfed apoptotic cells are barely seen in vivo under normal conditions. In order to understand the different steps of apoptotic cell clearance and to compare 'professional' phagocytes - macrophages and dendritic cells to 'non-professional' - tissue-resident neighboring cells, in vivo live imaging of the process is extremely valuable. Here we describe a protocol for studying apoptotic cell clearance in live Drosophila embryos. To follow the dynamics of different steps in phagocytosis we use specific markers for apoptotic cells and phagocytes. In addition, we can monitor two phagocyte systems in parallel: 'professional' macrophages and 'semi-professional' glia in the developing central nervous system (CNS). The method described here employs the Drosophila embryo as an excellent model for real time studies of apoptotic cell clearance.

Live Imaging of Apoptotic Cell Clearance during Drosophila Embryogenesis

Here we describe an effective method for studying dynamics of apoptotic cell clearance in vivo. This method employs live Drosophila embryos as a powerful model for monitoring phagocytosis of apoptotic cells using specific labeling of apoptotic cells and phagocytes.

يعيش التصوير من تخليص الخلية أفكارك أثناء<em&gt; ذبابة الفاكهة</em&gt; مرحلة التطور الجنيني

The  proper elimination of unwanted or aberrant cells through apoptosis and  subsequent phagocytosis (apoptotic cell clearance) is crucial for normal  ...

High Resolution Quantification of Crystalline Cellulose Accumulation in Arabidopsis Roots to Monitor Tissue-specific Cell Wall Modifications

Plant cells are surrounded by a cell wall, the composition of which determines their final size and shape. The cell wall is composed of a complex matrix containing polysaccharides that include cellulose microfibrils that form both crystalline structures and cellulose chains of amorphous organization. The orientation of the cellulose fibers and their concentrations dictate the mechanical properties of the cell. Several methods are used to determine the levels of crystalline cellulose, each bringing both advantages and limitations. Some can distinguish the proportion of crystalline regions within the total cellulose. However, they are limited to whole-organ analyses that are deficient in spatiotemporal information. Others relying on live imaging, are limited by the use of imprecise dyes. Here, we report a sensitive polarized light-based system for specific quantification of relative light retardance, representing crystalline cellulose accumulation in cross sections of Arabidopsis thaliana roots. In this method, the cellular resolution and anatomical data are maintained, enabling direct comparisons between the different tissues composing the growing root. This approach opens a new analytical dimension, shedding light on the link between cell wall composition, cellular behavior and whole-organ growth.

High Resolution Quantification of Crystalline Cellulose Accumulation in Arabidopsis Roots to Monitor Tissue-specific Cell Wall Modifications

Crystalline cellulose is an important constituent of the plant cell wall. However, its quantification at a cellular resolution is technically challenging. Here, we report the use of polarized light technology and root cross sections to obtain information of cell wall composition at a spatiotemporal resolution.

قرار الكمي عال من بلوري السليلوز تراكم في<em&gt; نبات الأرابيدوبسيس</em&gt; جذور لرصد الأنسجة محددة جدار الخلية تعديلات

Plant cells are surrounded by a cell wall, the composition of which determines their final size and shape. The cell wall is composed of a complex matrix ...

Identification of Novel Regulators of Plant Transpiration by Large-Scale Thermal Imaging Screening in Helianthus Annuus

Plant adaptation to biotic and abiotic stresses is governed by a variety of factors, among which the regulation of stomatal aperture in response to water deficit or pathogens plays a crucial role. Identifying small molecules that regulate stomatal movement can therefore contribute to understanding the physiological basis by which plants adapt to their environment. Large-scale screening approaches that have been used to identify regulators of stomatal movement have potential limitations: some rely heavily on the abscisic acid (ABA) hormone signaling pathway, therefore excluding ABA-independent mechanisms, while others rely on the observation of indirect, long-term physiological effects such as plant growth and development. The screening method presented here allows the large-scale treatment of plants with a library of chemicals coupled with a direct quantification of their transpiration by thermal imaging. Since evaporation of water through transpiration results in leaf surface cooling, thermal imaging provides a non-invasive approach to investigate changes in stomatal conductance over time. In this protocol, Helianthus annuus seedlings are grown hydroponically and then treated by root feeding, in which the primary root is cut and dipped into the chemical being tested. Thermal imaging followed by statistical analysis of cotyledonary temperature changes over time allows for the identification of bioactive molecules modulating stomatal aperture. Our proof-of-concept experiments demonstrate that a chemical can be carried from the cut root to the cotyledon of the sunflower seedling within 10 minutes. In addition, when plants are treated with ABA as a positive control, an increase in leaf surface temperature can be detected within minutes. Our method thus allows the efficient and rapid identification of novel molecules regulating stomatal aperture.

Identification of Novel Regulators of Plant Transpiration by Large-Scale Thermal Imaging Screening in Helianthus Annuus

We provide a method for identifying modulators of foliar transpiration by large-scale screening of a compound library.

تحديد المنظمين رواية نتح النبات من خلال فحص التصوير الحراري على نطاق واسع في Helianthus Annuus

Plant adaptation to biotic and abiotic stresses is governed by a variety of factors, among which the regulation of stomatal aperture in response to water ...

Label-Free Imaging of Lipid Storage Dynamics in Caenorhabditis elegans using Stimulated Raman Scattering Microscopy

Lipid metabolism is a fundamental physiological process necessary for cellular and organism health. Dysregulation of lipid metabolism often elicits obesity and many associated diseases including cardiovascular disorders, type II diabetes, and cancer. To advance the current understanding of lipid metabolic regulation, quantitative methods to precisely measure in vivo lipid storage levels in time and space have become increasingly important and useful. Traditional approaches to analyze lipid storage are semi-quantitative for microscopic assessment or lacking spatio-temporal information for biochemical measurement. Stimulated Raman scattering (SRS) microscopy is a label-free chemical imaging technology that enables rapid and quantitative detection of lipids in live cells with a subcellular resolution. As the contrast is exploited from intrinsic molecular vibrations, SRS microscopy also permits four-dimensional tracking of lipids in live animals. In the last decade, SRS microscopy has been widely used for small molecule imaging in biomedical research and overcome the major limitations of conventional fluorescent staining and lipid extraction methods. In the laboratory, we have combined SRS microscopy with the genetic and biochemical tools available to the powerful model organism, Caenorhabditis elegans, to investigate the distribution and heterogeneity of lipid droplets across different cells and tissues and ultimately to discover novel conserved signaling pathways that modulate lipid metabolism. Here, we present the working principles and the detailed setup of the SRS microscope and provide methods for its use in quantifying lipid storage at distinct developmental timepoints of wild-type and insulin signaling deficient mutant C. elegans.

Label-Free Imaging of Lipid Storage Dynamics in Caenorhabditis elegans using Stimulated Raman Scattering Microscopy

Stimulated Raman scattering (SRS) microscopy allows selective, label-free imaging of specific chemical moieties and it has been effectively employed to image lipid molecules in vivo. Here, we provide a brief introduction to the principle of SRS microscopy and describe methods for its use in imaging lipid storage in Caenorhabditis elegans.

التصوير الخالي من التسميات لديناميكيات تخزين الدهون في Elegans Caenorhabditis باستخدام المجهر التشتت رامان المحفزة

Lipid metabolism is a fundamental physiological process necessary for cellular and organism health. Dysregulation of lipid metabolism often elicits ...