فإن الكتاب أود أن أشكر الدكتور ريك بادجيت (اكسمان معهد، جامعة روتجرز بولاية نيو جيرسي) لهدية من [كدنا] DBL-1، والدكتور كريستوفر Rongo (اكسمان معهد، جامعة روتجرز بولاية نيو جيرسي) للحصول على علامة حقن. يقوم مختبر الدكتور بارث غرانت قصف مدفع الجينات لانخفاض نسخة دمج عدد من التركيبة GFP الموسومة-1 DBL. قدمت رينيه غارسيا مختبر المساعدة التقنية أثناء إنشاء texIs100. قدمت رينيه غارسيا، Lints روبين، وHongmin المختبرات تشين نصيحة الإنتاجية. وقد تم تمويل هذا العمل من قبل بدء أموال من وزارة TAMHSC الطب الجزيئي والخلوي. تم شراؤها في نطاق المجمع والغزل مبائر القرص مع الأموال التي تقدمها الإدارة، وكلية الطب TAMHSC من مكتب عميد.

<ol>
	<li>Giacomotto, J., Segalat, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-throughput+screening+and+small+animal+models,+where+are+we.">High-throughput screening and small animal models, where are we.</a> Br. J. Pharmacol. 160, 204-216 (2010).</li><li>Lamitina, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functional+genomic+approaches+in+C.+elegans.">Functional genomic approaches in C. elegans.</a> Methods in Molecular Biology. 351, 127-138 (2006).</li><li>Boutros, M., Ahringer, 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+art+and+design+of+genetic+screens:+RNA+interference.">The art and design of genetic screens: RNA interference.</a> Nat. Rev. Genet. 9, 554-566 (2008).</li><li>Praitis, V., Casey, E., Collar, D., Austin, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Creation+of+low-copy+integrated+transgenic+lines+in+Caenorhabditis+elegans.">Creation of low-copy integrated transgenic lines in Caenorhabditis elegans.</a> Genetics. 157, 1217-1226 (2001).</li><li>Yandell, M. D., Edgar, L. G., Wood, W. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Trimethylpsoralen+induces+small+deletion+mutations+in+Caenorhabditis+elegans.">Trimethylpsoralen induces small deletion mutations in Caenorhabditis elegans.</a> Proceedings of the National Academy of Sciences of the United States of America. 91, 1381-1385 (1994).</li><li>Frokjaer-Jensen, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single-copy+insertion+of+transgenes+in+Caenorhabditis+elegans.">Single-copy insertion of transgenes in Caenorhabditis elegans.</a> Nature Genetics. 40, 1375-1383 (2008).</li><li>Giordano-Santini, R., Dupuy, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Selectable+genetic+markers+for+nematode+transgenesis.">Selectable genetic markers for nematode transgenesis.</a> Cell. Mol. Life. Sci. , (2011).</li><li>Berkowitz, L. A., Knight, A. L., Caldwell, G. A., Caldwell, K. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Generation+of+Stable+Transgenic+C.+elegans+Using+Microinjection.">Generation of Stable Transgenic C. elegans Using Microinjection.</a> J. Vis. Exp. (18), e833 (2008).</li><li>Mello, C., Fire, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=DNA+transformation.">DNA transformation.</a> Methods in Cell Biology. 48, 451-482 (1995).</li><li>Simmer, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Loss+of+the+putative+RNA-directed+RNA+polymerase+RRF-3+makes+C.+elegans+hypersensitive+to+RNAi.">Loss of the putative RNA-directed RNA polymerase RRF-3 makes C. elegans hypersensitive to RNAi.</a> Curr. Biol. 12, 1317-1319 (2002).</li><li>Zhuang, J. J., Hunter, C. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tissue-specificity+of+Caenorhabditis+elegans+enhanced+RNAi+mutants.">Tissue-specificity of Caenorhabditis elegans enhanced RNAi mutants.</a> Genetics. , (2011).</li><li>Samuelson, A. V., Klimczak, R. R., Thompson, D. B., Carr, C. E., Ruvkun, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+of+Caenorhabditis+elegans+genes+regulating+longevity+using+enhanced+RNAi-sensitive+strains.">Identification of Caenorhabditis elegans genes regulating longevity using enhanced RNAi-sensitive strains.</a> Cold Spring Harbor Symposia on Quantitative Biology. 72, 489-497 (2007).</li><li>Wang, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Somatic+misexpression+of+germline+P+granules+and+enhanced+RNA+interference+in+retinoblastoma+pathway+mutants.">Somatic misexpression of germline P granules and enhanced RNA interference in retinoblastoma pathway mutants.</a> Nature. 436, 593-597 (2005).</li><li>Fraser, A. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functional+genomic+analysis+of+C.+elegans+chromosome+I+by+systematic+RNA+interference.">Functional genomic analysis of C. elegans chromosome I by systematic RNA interference.</a> Nature. 408, 325-330 (2000).</li><li>Kamath, 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=Systematic+functional+analysis+of+the+Caenorhabditis+elegans+genome+using+RNAi.">Systematic functional analysis of the Caenorhabditis elegans genome using RNAi.</a> Nature. 421, 231-237 (2003).</li><li>Peters, K., McDowall, J., Rose, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mutations+in+the+bli-4+(I)+locus+of+Caenorhabditis+elegans+disrupt+both+adult+cuticle+and+early+larval+development.">Mutations in the bli-4 (I) locus of Caenorhabditis elegans disrupt both adult cuticle and early larval development.</a> Genetics. , 129-195 (1991).</li><li>Thacker, C., Peters, K., Srayko, M., Rose, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+bli-4+locus+of+Caenorhabditis+elegans+encodes+structurally+distinct+kex2/subtilisin-like+endoproteases+essential+for+early+development+and+adult+morphology.">The bli-4 locus of Caenorhabditis elegans encodes structurally distinct kex2/subtilisin-like endoproteases essential for early development and adult morphology.</a> Genes &#38; Development. 9, 956-971 (1995).</li><li>Byerly, L., Cassada, R. C., Russell, R. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+life+cycle+of+the+nematode+Caenorhabditis+elegans.+I.+Wild-type+growth+and+reproduction.">The life cycle of the nematode Caenorhabditis elegans. I. Wild-type growth and reproduction.</a> Dev. Biol. 51, 23-33 (1976).</li><li>Stiernagle, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Maintenance+of+C.+elegans.">Maintenance of C. elegans.</a> WormBook. , 1-11 (2006).</li><li>Savage-Dunn, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetic+screen+for+small+body+size+mutants+in+C.+elegans+reveals+many+TGFbeta+pathway+components.">Genetic screen for small body size mutants in C. elegans reveals many TGFbeta pathway components.</a> Genesis. 35, 239-247 (2003).</li><li>Qu, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reliability+analysis+of+the+Ahringer+Caenorhabditis+elegans+RNAi+feeding+library:+a+guide+for+genome-wide+screens.">Reliability analysis of the Ahringer Caenorhabditis elegans RNAi feeding library: a guide for genome-wide screens.</a> BMC Genomics. 12, 1471-2164 (2011).</li><li>Nelson, 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=A+Bow-Tie+Genetic+Architecture+for+Morphogenesis+Suggested+by+a+Genome-Wide+RNAi+Screen+in+Caenorhabditis+elegans.">A Bow-Tie Genetic Architecture for Morphogenesis Suggested by a Genome-Wide RNAi Screen in Caenorhabditis elegans.</a> PLoS Genetics. 7, e1002010 (2011).</li><li>Timmons, L., Fire, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Specific+interference+by+ingested+dsRNA.">Specific interference by ingested dsRNA.</a> Nature. 395, 854 (1998).</li><li>Sarin, S., Prabhu, S., O'Meara, M. M., Pe'er, I., Hobert, O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Caenorhabditis+elegans+mutant+allele+identification+by+whole-genome+sequencing.">Caenorhabditis elegans mutant allele identification by whole-genome sequencing.</a> Nature Methods. 5, 865-867 (2008).</li><li>Lewis, J. A., Fleming, J. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Basic+culture+methods.">Basic culture methods.</a> Methods in Cell Biology. 48, 3-29 (1995).</li><li>Brenner, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+genetics+of+Caenorhabditis+elegans.">The genetics of Caenorhabditis elegans.</a> Genetics. 77, 71-94 (1974).</li></ol>

ليس لدينا ما يكشف.

طريقة فحص رني المقدمة هنا يمكن تحليل حساسة وسريعة من المنتجات الجينات المطلوبة لالنمط الظاهري (أو المعدلة وراثيا) طبيعي تال للمرحلة الجنينية. المثال المعروض هو الشاشة عن الجينات المسؤولة عن توطين التحت خلوية من البروتين الموسومة fluorescently. ومع ذلك، يمكن تعديل هذا البروتوكول لتحديد الجينات التي تؤثر على الظواهر تال للمرحلة الجنينية الأخرى ذات الاهتمام. هذا الأسلوب يستفيد من مرشح نهج الجينات باستخدام مكتبة رني. شاشات الوراثية إلى الأمام باستخدام تقنيات تحديد الطفرات المستحثة الأليلات رواية عشوائيا، ولكن تلك الأليلات تتطلب وقتا كبيرا وجهدا، و / أو أموال لتحديد 24. مع مكتبة [كدنا]، من ناحية أخرى، تتابع إدراج [كدنا] الذي تسبب في النمط الظاهري رني من مصلحة يؤكد بسرعة الجين مرشح. أيضا، والاستنساخ جاهزة للإدراج [كدنا] تسهيل التحليلات النهائية للمرشحين التي تم تحديدها. وعلاوة على ذلك، الجينات التي تكون قاتلة عندما تحورويمكن تحديد وتحليلها باستخدام رني. عن طريق وضع الحيوانات التي تحاك على البكتيريا التي يسببها، وهذه الطريقة تسمح للمراقبة من العيوب تال للمرحلة الجنينية للجينات التي لها أيضا دور حيوي الجنينية. العناية للتأكد من أن لا يتم تجويع الحيوانات المرصودة. يمكن أن تؤثر على النمط الظاهري التجويع للحيوان. إذا تم تحديد الظواهر رواية [رني في الجياع والحيوانات، وتكرار للتأكيد على أن النمط الظاهري هو نتيجة للرني وعدم الموت جوعا. لمنع المجاعة، واستخدام البكتيريا الجديدة التي قد نمت إلى مرحلة ثابتة (وسيط النمو للغاية &quot;غائم&quot;)، واستخدم فقط ~ 30 الحيوانات لكل بئر.

<table border="1" style=";text-align:right;direction:rtl"><tbody><tr><td> اسم كاشف </td><td> شركة </td><td> فهرس العدد </td><td> تعليقات </td></tr><tr><td> NGM آجار </td><td> الديدان الخيطية النمو المتوسطة </td><td> المكافحة المتكاملة للآفات والعلم، وشركة </td><td> ويمكن أن تكون مستعدة بعد بروتوكول أجار NGM 25 </td></tr><tr><td> M9 متوسطة </td><td> 22mm و KH 2 PO 4، 42mM نا 2 هبو 4، 86mM كلوريد الصوديوم، 1 مم MgSO 4 </td><td></td><td> 26 </td></tr><tr><td> أجار أجار </td><td> EMD شركة الكيماويات </td><td> 1.01614.1000 </td><td> 2٪ في الماء لوحات NGM. 4٪ في الماء لمنصات شريحة المجهر (الأوتوكلاف في البداية، والميكروويف لتذوب بعد ذلك). </td></tr><tr><td> Bacto البيبتون </td><td> بيكتون ديكنسون - Difco CP </td><td> 211677 </td><td> 0.25٪ </TD&gt; </tr><tr><td> IPTG </td><td> بحث منتجات شركة الدولية </td><td> I56000-5.0 </td><td> 1 تركيز نهائي ملي </td></tr><tr><td> كربنيسيلين </td><td> بحث منتجات شركة الدولية </td><td> C46000-5.0 </td><td> 50 ميكروغرام / مل تخفيف العمل </td></tr><tr><td> LB حساء لينوكس </td><td> بيكتون ديكنسون - Difco CP </td><td> 240230 </td><td> 20 جم / لتر </td></tr><tr><td> التتراسيكلين </td><td> سيغما </td><td> 268054 </td><td> 12.5 ميكروغرام / مل تخفيف العمل </td></tr><tr><td> هيبوكلوريت الصوديوم </td><td> أي علامة تجارية </td><td> 5٪ التبييض المنزلي </td><td> استخدام التبييض الطازجة. </td></tr><tr><td> هيدروكسيد الصوديوم </td><td> أي علامة تجارية </td><td> CAS 1310-73-2 </td><td> 5 N الأوراق المالية </td></tr><tr><td> M9 المتوسطة </td><td> Wormlab وصفة كتاب </td><td> <a href="http://130.15.90.245/wormlab_recipe_book.htm#Commonlab">http://1</a>30.15.90.245/wormlab_recipe_book.htm # Commonlab </td><td> 26 </td></tr><tr><td> levamisol </td><td> سيغما </td><td> 31742 </td><td> 100 ميكرون - 1 ملم تخفيف العمل </td></tr><tr><td> أزيد الصوديوم </td><td> فيشر العلمية </td><td> S227 </td><td> 10 مليمتر في تخفيف العمل M9 </td></tr><tr><td> 24 لوحة جيد </td><td> غرينر بيو واحد </td><td> 662160 </td><td> VWR موزع </td></tr><tr><td> مجهر الشرائح </td><td> أي علامة تجارية </td><td> 75 × 25 × 1 ملم </td><td></td></tr><tr><td> زلات مجهر الغطاء </td><td> أي علامة تجارية </td><td> 22 × 22 مم No.1.5 </td><td> استخدام سماكة موصى بها من قبل الشركة المصنعة للمجهر. </td></tr><tr><td> مجمع المجهر </td><td> كارل زايس، وشركة </td><td> A1m </td><td> استخدام الأهداف والمرشحات لتلبية احتياجات التجربة. </td></tr><tr><td> وسائل الاعلام مضخة</td><td> Manostat Varistaltic مضخة </td><td> كيت نموذج # 72-620-000 </td><td> استخدام أنابيب والضبط المناسب للجهاز </td></tr></tbody></table>

rnai screening to identify postembryonic phenotypes in c. elegans

وقد ثبت جيم ايليجانس أن يكون نظام نموذجا قيما للاكتشاف وتوصيف وظيفي للجينات كثيرة ومسارات الجينات 1. أدوات أكثر تطورا وموارد لإجراء دراسات في هذا النظام وتسهيل اكتشاف الجينات مع استمرار الظواهر أكثر دهاء أو الأدوار. هنا نقدم لبروتوكول المعمم نحن تكييفها لتحديد C. ايليجانس الجينات مع الظواهر تال للمرحلة الجنينية من الاهتمام باستخدام رني 2. يتم تعديل بسهولة هذا الإجراء لفحص النمط الظاهري في الاختيار، سواء من قبل بصريات ضوء أو مضان على مجهر تشريح أو مركب. هذا البروتوكول فحص تستفيد من الأصول المادية للكائن الحي والأدوات الجزيئية وجيم وقد أنتجت الأبحاث ايليجانس المجتمع. كمثال على ذلك، ونحن لشرح استخدام من التحوير المتكاملة التي تعبر عن منتج فلوري في شاشة رني لتحديد الجينات اللازمة لتوطين طبيعية من هذامنتج في مرحلة متأخرة اليرقات والكبار. أولا، استخدمنا المتاحة تجاريا مكتبة رني الجينومية مع كامل طول إدراج [كدنا]. هذه المكتبة يسهل التعرف السريع على تعدد المرشحين من قبل تخفيض رني المرشح منتج الجين. الثانية، ولدت لدينا خبير التحوير المتكاملة التي تعبر عن البروتين لدينا الموسومة fluorecently من اهتمام في خلفية رني حساسة. الثالثة، من خلال تعريض الحيوانات التي تحاك لرني، هذه الشاشة يسمح تحديد المنتجات الجينات التي لها دور حيوي الجنينية التي من شأنها أن تخفي ذلك دورا في مرحلة ما بعد الجنينية في تنظيم بروتين من الفائدة. أخيرا، هذه الشاشة يستخدم مجهر مركب مجهزة لقرار خلية واحدة.

Watch this Scientific Journal Video about RNAi Screening to Identify Postembryonic Phenotypes in C. elegans at JoVE.com

RNAi Screening to Identify Postembryonic Phenotypes in C. elegans

نحن وصفا لطريقة توعية لتعريف المنظمين تال للمرحلة الجنينية من بروتين تعبير والتوطين في<em&gt; C. ايليجانس</em&gt; باستخدام شاشة الجينومية رني المستندة إلى والتحوير المتكاملة التي تعبر عن وظيفية، والبروتين الموسومة fluorescently.

[رني الفرز لتحديد الظواهر تال للمرحلة الجنينية في C. ايليجانس</em

C. elegans has proven to be a valuable model system for the discovery and functional characterization of many genes and gene pathways1. More sophisticated ...

rnai-screening-to-identify-postembryonic-phenotypes-in-c-elegans

Nanyang Technological University

Research

JoVE Journal

Biology

RNAi Screening to Identify Postembryonic Phenotypes in C. elegans

17.0K Views.  Texas A&M University System Health Science Center. نحن وصفا لطريقة توعية لتعريف المنظمين تال للمرحلة الجنينية من بروتين تعبير والتوطين في C. ايليجانس باستخدام شاشة الجينومية رني المستندة إلى والتحوير المتكاملة التي تعبر عن وظيفية، والبروتين الموسومة fluorescently.

Video: RNAi Screening to Identify Postembryonic Phenotypes in C. elegans

Generation of Stable Transgenic C. elegans Using Microinjection

Transgenic Caenorhabditis elegans can be readily created via microinjection of a DNA plasmid solution into the gonad 1. The plasmid DNA rearranges to form extrachromosomal concatamers that are stably inherited, though not with the same efficiency as actual chromosomes 2. A gene of interest is co-injected with an obvious phenotypic marker, such as rol-6 or GFP, to allow selection of transgenic animals under a dissecting microscope. The exogenous gene may be expressed from its native promoter for cellular localization studies. Alternatively, the transgene can be driven by a different tissue-specific promoter to assess the role of the gene product in that particular cell or tissue. This technique efficiently drives gene expression in all tissues of C. elegans except for the germline or early embryo 3. Creation of transgenic animals is widely utilized for a range of experimental paradigms. This video demonstrates the microinjection procedure to generate transgenic worms. Furthermore, selection and maintenance of stable transgenic C. elegans lines is described.

This video demonstrates the technique of microinjection into the gonad of C. elegans to create transgenic animals.

توليد مستقرة ايليجانس جيم المعدلة وراثيا عن طريق Microinjection

Transgenic Caenorhabditis elegans can be readily created via microinjection of a DNA plasmid solution into the gonad 1.  The plasmid DNA rearranges to ...

MISSION esiRNA for RNAi Screening in Mammalian Cells

RNA interference (RNAi) is a basic cellular mechanism for the control of gene expression. RNAi is induced by short double-stranded RNAs also known as small interfering RNAs (siRNAs). The short double-stranded RNAs originate from longer double stranded precursors by the activity of Dicer, a protein of the RNase III family of endonucleases. The resulting fragments are components of the RNA-induced silencing complex (RISC), directing it to the cognate target mRNA. RISC cleaves the target mRNA thereby reducing the expression of the encoded protein1,2,3. RNAi has become a powerful and widely used experimental method for loss of gene function studies in mammalian cells utilizing small interfering RNAs.
Currently two main methods are available for the production of small interfering RNAs. One method involves chemical synthesis, whereas an alternative method employs endonucleolytic cleavage of target specific long double-stranded RNAs by RNase III in vitro. Thereby, a diverse pool of siRNA-like oligonucleotides is produced which is also known as endoribonuclease-prepared siRNA or esiRNA. A comparison of efficacy of chemically derived siRNAs and esiRNAs shows that both triggers are potent in target-gene silencing. Differences can, however, be seen when comparing specificity. Many single chemically synthesized siRNAs produce prominent off-target effects, whereas the complex mixture inherent in esiRNAs leads to a more specific knockdown10.
In this study, we present the design of genome-scale MISSION esiRNA libraries and its utilization for RNAi screening exemplified by a DNA-content screen for the identification of genes involved in cell cycle progression. We show how to optimize the transfection protocol and the assay for screening in high throughput. We also demonstrate how large data-sets can be evaluated statistically and present methods to validate primary hits. Finally, we give potential starting points for further functional characterizations of validated hits.

Here we use a human esiRNA library in a high-throughput screen for genes involved in cell division. We demonstrate how to set up and conduct an esiRNA screens, as well as how to analyze and validate the results.

esiRNA بعثة لفحص رني في خلايا الثدييات

RNA interference (RNAi) is a basic cellular mechanism for the control of gene expression. RNAi is induced by short double-stranded RNAs also known as ...

High-throughput Screening and Biosensing with Fluorescent C. elegans Strains

High-throughput screening (HTS) is a powerful approach for identifying chemical modulators of biological processes. However, many compounds identified in screens using cell culture models are often found to be toxic or pharmacologically inactive in vivo1-2. Screening in whole animal models can help avoid these pitfalls and streamline the path to drug development.
C. elegans is a multicellular model organism well suited for HTS. It is small (&lt;1 mm) and can be economically cultured and dispensed in liquids. C. elegans is also one of the most experimentally tractable animal models permitting rapid and detailed identification of drug mode-of-action3.
We describe a protocol for culturing and dispensing fluorescent strains of C. elegans for high-throughput screening of chemical libraries or detection of environmental contaminants that alter the expression of a specific gene. Large numbers of developmentally synchronized worms are grown in liquid culture, harvested, washed, and suspended at a defined density. Worms are then added to black, flat-bottomed 384-well plates using a peristaltic liquid dispenser. Small molecules from a chemical library or test samples (e.g., water, food, or soil) can be added to wells with worms. In vivo, real-time fluorescence intensity is measured with a fluorescence microplate reader. This method can be adapted to any inducible gene in C. elegans for which a suitable reporter is available. Many inducible stress and developmental transcriptional pathways are well defined in C. elegans and GFP transgenic reporter strains already exist for many of them4. When combined with the appropriate transgenic reporters, our method can be used to screen for pathway modulators or to develop robust biosensor assays for environmental contaminants. 
We demonstrate our C. elegans culture and dispensing protocol with an HTS assay we developed to monitor the C. elegans cap &#x2018;n&#x2019; collar transcription factor SKN-1. SKN-1 and its mammalian homologue Nrf2 activate cytoprotective genes during oxidative and xenobiotic stress5-10. Nrf2 protects mammals from numerous age-related disorders such as cancer, neurodegeneration, and chronic inflammation and has become a major chemotherapeutic target11-13.Our assay is based on a GFP transgenic reporter for the SKN-1 target gene gst-414, which encodes a glutathione-s transferase6. The gst-4 reporter is also a biosensor for xenobiotic and oxidative chemicals that activate SKN-1 and can be used to detect low levels of contaminants such as acrylamide and methyl-mercury15-16.

High-throughput Screening and Biosensing with Fluorescent C. elegans Strains

A procedure for liquid-based culturing and dispensing of C. elegans strains expressing fluorescent reporter proteins is described that does not require expensive sorting equipment. This approach can be applied to numerous inducible C. elegans genes for drug discovery or biosensing of contaminants.

الفرز الفائق الإنتاجية وBiosensing مع نيون C. ايليجانس سلالات

High-throughput screening (HTS) is a powerful approach for identifying chemical modulators of biological processes.  However, many compounds identified in ...

Quantitative and Automated High-throughput Genome-wide RNAi Screens in C. elegans

RNA interference is a powerful method to understand gene function, especially when conducted at a whole-genome scale and in a quantitative context. In C. elegans, gene function can be knocked down simply and efficiently by feeding worms with bacteria expressing a dsRNA corresponding to a specific gene 1. While the creation of libraries of RNAi clones covering most of the C. elegans genome 2,3 opened the way for true functional genomic studies (see for example 4-7), most established methods are laborious. Moy and colleagues have developed semi-automated protocols that facilitate genome-wide screens 8. The approach relies on microscopic imaging and image analysis. 
	Here we describe an alternative protocol for a high-throughput genome-wide screen, based on robotic handling of bacterial RNAi clones, quantitative analysis using the COPAS Biosort (Union Biometrica (UBI)), and an integrated software: the MBioLIMS (Laboratory Information Management System from Modul-Bio) a technology that provides increased throughput for data management and sample tracking. The method allows screens to be conducted on solid medium plates. This is particularly important for some studies, such as those addressing host-pathogen interactions in C. elegans, since certain microbes do not efficiently infect worms in liquid culture.
	We show how the method can be used to quantify the importance of genes in anti-fungal innate immunity in C. elegans. In this case, the approach relies on the use of a transgenic strain carrying an epidermal infection-inducible fluorescent reporter gene, with GFP under the control of the promoter of the antimicrobial peptide gene nlp 29 and a red fluorescent reporter that is expressed constitutively in the epidermis. The latter provides an internal control for the functional integrity of the epidermis and nonspecific transgene silencing9. When control worms are infected by the fungus they fluoresce green. Knocking down by RNAi a gene required for nlp 29 expression results in diminished fluorescence after infection. Currently, this protocol allows more than 3,000 RNAi clones to be tested and analyzed per week, opening the possibility of screening the entire genome in less than 2 months.

Quantitative and Automated High-throughput Genome-wide RNAi Screens in C. elegans

We describe a protocol using C. elegans and RNAi feeding libraries that allows automated measurement of multiple parameters such as fluorescence, size and opacity of individual worms in a population. We give one example of a screen to identify genes involved in anti-fungal innate immunity in C. elegans.

الكمية والآلي عالية الإنتاجية الجينوم على نطاق شاشات رني في C. ايليجانس</em

RNA interference is a powerful method to understand gene function, especially when conducted at a whole-genome scale and in a quantitative context. In C. ...

Creating Defined Gaseous Environments to Study the Effects of Hypoxia on C. elegans

Oxygen is essential for all metazoans to survive, with one known exception1. Decreased O2 availability (hypoxia) can arise during states of disease, normal development or changes in environmental conditions2-5. Understanding the cellular signaling pathways that are involved in the response to hypoxia could provide new insight into treatment strategies for diverse human pathologies, from stroke to cancer. This goal has been impeded, at least in part, by technical difficulties associated with controlled hypoxic exposure in genetically amenable model organisms.
The nematode Caenorhabditis elegans is ideally suited as a model organism for the study of hypoxic response, as it is easy to culture and genetically manipulate. Moreover, it is possible to study cellular responses to specific hypoxic O2 concentrations without confounding effects since C. elegans obtain O2 (and other gasses) by diffusion, as opposed to a facilitated respiratory system6. Factors known to be involved in the response to hypoxia are conserved in C. elegans. The actual response to hypoxia depends on the specific concentration of O2 that is available. In C. elegans, exposure to moderate hypoxia elicits a transcriptional response mediated largely by hif-1, the highly-conserved hypoxia-inducible transcription factor6-9. C .elegans embryos require hif-1 to survive in 5,000-20,000 ppm O27,10. Hypoxia is a general term for "less than normal O2". Normoxia (normal O2) can also be difficult to define. We generally consider room air, which is 210,000 ppm O2 to be normoxia. However, it has been shown that C. elegans has a behavioral preference for O2 concentrations from 5-12% (50,000-120,000 ppm O2)11. In larvae and adults, hif-1 acts to prevent hypoxia-induced diapause in 5,000 ppm O212. However, hif-1 does not play a role in the response to lower concentrations of O2 (anoxia, operational definition &lt;10 ppm O2)13. In anoxia, C. elegans enters into a reversible state of suspended animation in which all microscopically observable activity ceases10. The fact that different physiological responses occur in different conditions highlights the importance of having experimental control over the hypoxic concentration of O2.
Here, we present a method for the construction and implementation of environmental chambers that produce reliable and reproducible hypoxic conditions with defined concentrations of O2. The continual flow method ensures rapid equilibration of the chamber and increases the stability of the system. Additionally, the transparency and accessibility of the chambers allow for direct visualization of animals being exposed to hypoxia. We further demonstrate an effective method of harvesting C. elegans samples rapidly after exposure to hypoxia, which is necessary to observe many of the rapidly-reversed changes that occur in hypoxia10,14. This method provides a basic foundation that can be easily modified for individual laboratory needs, including different model systems and a variety of gasses.

Creating Defined Gaseous Environments to Study the Effects of Hypoxia on C. elegans

This paper details how to use continuous-flow hypoxia chambers to generate atmospheres with defined concentrations of O2 to understand biological responses to decreased O2. This system is easy to setup and maintain, and flexible enough to suit a wide range of O2 concentrations and model systems

خلق بيئات الغازية محددة لدراسة تأثير نقص الأكسجة في<em&gt; C. ايليجانس</em

Oxygen is essential for all metazoans to survive, with one known exception1. Decreased O2 availability (hypoxia) can arise during states of disease, ...

C. elegans Chemotaxis Assay

Many organisms use chemotaxis to seek out food sources, avoid noxious substances, and find mates. Caenorhabditis elegans has impressive chemotaxis behavior.
 The premise behind testing the response of the worms to an odorant is to place them in an area and observe the movement evoked in response to an odorant. Even with the many available assays, optimizing worm starting location relative to both the control and test areas, while minimizing the interaction of worms with each other, while maintaining a significant sample size remains a work in progress 1-10. The method described here aims to address these issues by modifying the assay developed by Bargmann et al.1. A Petri dish is divided into four quadrants, two opposite quadrants marked "Test" and two are designated "Control". Anesthetic is placed in all test and control sites. The worms are placed in the center of the plate with a circle marked around the origin to ensure that non-motile worms will be ignored. Utilizing a four-quadrant system rather than one 2 or two 1 eliminates bias in the movement of the worms, as they are equidistant from test and control samples, regardless of which side of the origin they began. This circumvents the problem of worms being forced to travel through a cluster of other worms to respond to an odorant, which can delay worms or force them to take a more circuitous route, yielding an incorrect interpretation of their intended path. This method also shows practical advantages by having a larger sample size and allowing the researcher to run the assay unattended and score the worms once the allotted time has expired.

C. elegans Chemotaxis Assay

A method of quantitatively evaluating the chemotactic response of Caenorhabditis elegans is described. A chemotactic index (CI) was employed as a way to precisely evaluate the response of worms to certain targets, and serve as a platform of comparison between strains and compounds of interest.

C. ايليجانس الانجذاب الكيميائي الفحص

Many organisms use chemotaxis to seek out food sources, avoid noxious substances, and find mates.  Caenorhabditis elegans has impressive chemotaxis ...

Antibody Staining in C. Elegans Using &quot;Freeze-Cracking&quot;

To stain C. elegans with antibodies, the relatively impermeable cuticle must be bypassed by chemical or mechanical methods. "Freeze-cracking" is one method used to physically pull the cuticle from nematodes by compressing nematodes between two adherent slides, freezing them, and pulling the slides apart. Freeze-cracking provides a simple and rapid way to gain access to the tissues without chemical treatment and can be used with a variety of fixatives. However, it leads to the loss of many of the specimens and the required compression mechanically distorts the sample. Practice is required to maximize recovery of samples with good morphology. Freeze-cracking can be optimized for specific fixation conditions, recovery of samples, or low non-specific staining, but not for all parameters at once. For antibodies that require very hard fixation conditions and tolerate the chemical treatments needed to chemically permeabilize the cuticle, treatment of intact nematodes in solution may be preferred. If the antibody requires a lighter fix or if the optimum fixation conditions are unknown, freeze-cracking provides a very useful way to rapidly assay the antibody and can yield specific subcellular and cellular localization information for the antigen of interest.

Antibody Staining in C. Elegans Using "Freeze-Cracking"

"Freeze-cracking," a method for exposing the inner tissues of the nematode C. elegans to antibodies for protein localization, is demonstrated.

تلوين الأجسام المضادة في<em&gt; C. ايليجانس</em&gt; عن طريق &quot;تجميد تكسير&quot;

To stain C.  elegans with antibodies, the relatively impermeable cuticle must be  bypassed by chemical or mechanical methods.  "Freeze-cracking" is one ...

Large-scale Gene Knockdown in C. elegans Using dsRNA Feeding Libraries to Generate Robust Loss-of-function Phenotypes

RNA interference by feeding worms bacteria expressing dsRNAs has been a useful tool to assess gene function in C. elegans. While this strategy works well when a small number of genes are targeted for knockdown, large scale feeding screens show variable knockdown efficiencies, which limits their utility. We have deconstructed previously published RNAi knockdown protocols and found that the primary source of the reduced knockdown can be attributed to the loss of dsRNA-encoding plasmids from the bacteria fed to the animals. Based on these observations, we have developed a dsRNA feeding protocol that greatly reduces or eliminates plasmid loss to achieve efficient, high throughput knockdown. We demonstrate that this protocol will produce robust, reproducible knock down of C. elegans genes in multiple tissue types, including neurons, and will permit efficient knockdown in large scale screens. This protocol uses a commercially available dsRNA feeding library and describes all steps needed to duplicate the library and perform dsRNA screens. The protocol does not require the use of any sophisticated equipment, and can therefore be performed by any C. elegans lab.

Large-scale Gene Knockdown in C. elegans Using dsRNA Feeding Libraries to Generate Robust Loss-of-function Phenotypes

While dsRNA feeding in C. elegans is a powerful tool to assess gene function, current protocols for large scale feeding screens result in variable knockdown efficiencies. We describe an improved protocol for performing large scale RNAi feeding screens that results in highly efficacious and reproducible knockdown of gene expression.

ضربة قاضية الجينات على نطاق واسع في<em&gt; C. ايليجانس</em&gt; استخدام المكتبات تغذية الرنا المزدوج الجديلة لتوليد قوية لتخفيف من وظيفة الظواهر

RNA interference by feeding worms bacteria expressing dsRNAs has been a useful tool to assess gene function in C. elegans. While this strategy works well ...

An Anoxia-starvation Model for Ischemia/Reperfusion in C. elegans

Protocols for anoxia/starvation in the genetic model organism C. elegans simulate ischemia/reperfusion. Worms are separated from bacterial food and placed under anoxia for 20 hr&#160;(simulated ischemia), and subsequently moved to a normal atmosphere with food (simulated reperfusion). This experimental paradigm results in increased death and neuronal damage, and techniques are presented to assess organism viability, alterations to the morphology of touch neuron processes, as well as touch sensitivity, which represents the behavioral output of neuronal function. Finally, a method for constructing hypoxic incubators using common kitchen storage containers is described. The addition of a mass flow control unit allows for alterations to be made to the gas mixture in the custom incubators, and a circulating water bath allows for both temperature control and makes it easy to identify leaks. This method provides a low cost alternative to commercially available units.

An Anoxia-starvation Model for Ischemia/Reperfusion in C. elegans

A protocol is described that uses anoxia/starvation in C. elegans to model ischemia/reperfusion. Functional outcomes include increased mortality, visible abnormalities in GFP-labeled neuronal processes, and impaired behavioral responses that require neuronal function.

نموذج نقص الأكسجين المجاعة لنقص التروية / ضخه في<em&gt; C. ايليجانس</em

Protocols for anoxia/starvation in the genetic model organism C. elegans simulate ischemia/reperfusion. Worms are separated from bacterial food and placed ...

Methods to Assess Subcellular Compartments of Muscle in C. elegans

Muscle is a dynamic tissue that responds to changes in nutrition, exercise, and disease state. The loss of muscle mass and function with disease and age are significant public health burdens. We currently understand little about the genetic regulation of muscle health with disease or age. The nematode C. elegans is an established model for understanding the genomic regulation of biological processes of interest. This worm&#8217;s body wall muscles display a large degree of homology with the muscles of higher metazoan species. Since C. elegans is a transparent organism, the localization of GFP to mitochondria and sarcomeres allows visualization of these structures in vivo. Similarly, feeding animals cationic dyes, which accumulate based on the existence of a mitochondrial membrane potential, allows the assessment of mitochondrial function in vivo. These methods, as well as assessment of muscle protein homeostasis, are combined with assessment of whole animal muscle function, in the form of movement assays, to allow correlation of sub-cellular defects with functional measures of muscle performance. Thus, C. elegans provides a powerful platform with which to assess the impact of mutations, gene knockdown, and/or chemical compounds upon muscle structure and function. Lastly, as GFP, cationic dyes, and movement assays are assessed non-invasively, prospective studies of muscle structure and function can be conducted across the whole life course and this at present cannot be easily investigated in vivo in any other organism.

Methods to Assess Subcellular Compartments of Muscle in C. elegans

Skeletal muscle is essential for locomotion and is the bodies&#8217; main protein store. Muscle health measurements within C. elegans are described. Prospective changes to muscle structure and function are assessed using localized GFP and cationic dyes.

طرق لتقييم التحت خلوية من المقصورات في العضلات<em&gt; C. ايليجانس</em

Muscle is a dynamic tissue that responds to changes in nutrition, exercise, and disease state. The loss of muscle mass and function with disease and age ...