المؤلفون ممتنون جدا لسومر RJ وانغ X للحصول على مساعدة microinjection ، فضلا عن التعليقات الثاقبة من المراجعين المجهولين. ويؤيد هذا العمل من قبل المعاهد الوطنية للصحة منح SC2GM089602.

<ol>
	<li>Fire, A., Xu, S., Montgomery, M. K., Kostas, S. A., Driver, S. E., Mello, C. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Potent+and+specific+genetic+interference+by+double-stranded+RNA+in+Caenorhabditis+elegans.">Potent and specific genetic interference by double-stranded RNA in Caenorhabditis elegans.</a> Nature. 391, 806-811 (1998).</li><li>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=Reverse+Genetics.">Reverse Genetics.</a> Wormbook. , (2006).</li><li>Mello, C. C., Kramer, J. M., Stinchcomb, D., Ambros, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficient+gene+transfer+in+C.+elegans:+extrachromosomal+maintenance+and+integration+of+transforming+sequences.">Efficient gene transfer in C. elegans: extrachromosomal maintenance and integration of transforming sequences.</a> EMBO J. 10, 3959-3970 (1991).</li><li>Junio, A. J., Li, X., Massery, H. C., Nolan, T. J., Lamitina, S. T., Sundaram, M. V., Lok, J. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Strongyloides+stercoralis:+cell-+and+tissue-specific+transgene+expression+and+co-transformation+with+vector+constructs+incorporating+a+common+multifunctional+3'+UTR.">Strongyloides stercoralis: cell- and tissue-specific transgene expression and co-transformation with vector constructs incorporating a common multifunctional 3' UTR.</a> Exp. Parasitology. 118, 253-265 (2008).</li><li>Schlager, B., Wang, X., Braach, G., Sommer, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+cloning+of+a+dominant+roller+mutant+and+establishment+of+DNA-mediated+transformation+in+the+nematode+Pristionchus+pacificus.">Molecular cloning of a dominant roller mutant and establishment of DNA-mediated transformation in the nematode Pristionchus pacificus.</a> Genesis. 47, 300-304 (2009).</li><li>Hong, R. L., Sommer, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pristionchus+pacificus:+a+well-rounded+nematode.">Pristionchus pacificus: a well-rounded nematode.</a> Bioessays. 28, 651-659 (2006).</li><li>Hong, R. L., Sommer, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemoattraction+in+Pristionchus+nematodes+and+implications+for+insect+recognition.">Chemoattraction in Pristionchus nematodes and implications for insect recognition.</a> Curr. Biol. 16, 2359-2365 (2006).</li><li>Rudel, D., Riebesell, M., Sommer, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gonadogenesis+in+Pristionchus+pacificus+and+organ+evolution:+development,+adult+morphology+and+cell-cell+interactions+in+the+hermaphrodite+gonad.">Gonadogenesis in Pristionchus pacificus and organ evolution: development, adult morphology and cell-cell interactions in the hermaphrodite gonad.</a> Dev. Biol. 277, 200-221 (2005).</li><li>Chalfie, M., Tu, Y., Euskirchen, G., Ward, W. W., Prasher, D. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Green+fluorescent+protein+as+a+marker+for+gene+expression.">Green fluorescent protein as a marker for gene expression.</a> Science. 11, 802-805 (1994).</li><li>Chaudhuri, J., Parihar, M., Pires-daSilva, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+Introduction+to+Worm+Lab:+from+Culturing+Worms+to+Mutagenesis.">An Introduction to Worm Lab: from Culturing Worms to Mutagenesis.</a> J. Vis. Exp. (47), e2293-e2293 (2011).</li><li>Evans, T. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transformation+and+Microinjection.">Transformation and Microinjection.</a> Wormbook. , (2006).</li></ol>

الإعلان عن أي تضارب في المصالح.

تم العثور على P. السكان pacificus بالتعاون الوثيق مع مختلف أنواع خنفساء الجعران في جميع أنحاء العالم ، وهو نموذج الخيطية وسيطة بين الذين يعيشون بحرية والديدان الطفيلية. قوة P. pacificus باعتبارها النموذج الحي الناشئة يكمن في دمج خرائط وراثية والمادية التي تشجع ع...

<table border="1" style=";text-align:right;direction:rtl"><tbody><tr><th> المنتج : </th><th> كتالوج # : </th><th> المورد : </th></tr><tr><td> DMI3000 حقن المجهر </td><td> DMI3000 </td><td> لايكا </td></tr><tr><td> Microinjector مناور (محرك مباشر) </td><td> Narashige مشتركة BC - 3 الكرة </td><td> Tritech بحوث </td></tr><tr><td> إبرة بولير </td><td> Narashige PC - 10 </td><td> Tritech بحوث </td></tr><tr><td> MicroInjector ™ كل الرقمية المتعددة ضغط النظام </td><td> Narashige MINJ - D </td><td> Tritech بحوث </td></tr><tr><td> GeneElute ™ الحمض النووي الجينوم الثدييات Miniprep كيت </td><td> G1N70 </td><td> سيغما </td></tr><tr><td> pJet استنساخ عدة جت </td><td> K1231 </td><td> Fermentas </td></tr><tr><td> GeneJET البلازميد Miniprep طقم </td><td> K0502 </td><td> Fermentas </td></tr><tr><td> الحمض النووي النظافة والمكثف ™ </td><td> D4005 </td><td> الإنزيم بحوث </td></tr><tr><td> BLOCK - IT ™ رني النسخ ® TOPO طقم </td><td> K3500 K3650 - 01 و 0 -1 </td><td> Invitrogen </td></tr><tr><td> Difco ™ آجار نوبل </td><td> DF0142 - 15-2 </td><td> فيشر Scientifi </td></tr><tr><td> ميكروسكوب تغطية (1.5 -- 0.16 و 0.19mm سميكة ؛ الحجم : 50 × 45mm) </td><td> 12-554 - F </td><td> فيشر العلمية </td></tr><tr><td> الزجاج الشعيرات الدموية (خيوط) </td><td> 615000 </td><td> نظم AM </td></tr><tr><td> زيت البارافين (الثقيلة) </td><td> O122 - 1 </td><td> فيشر العلمية </td></tr><tr><td> KH 2 PO 4 </td><td> P386 - 500 </td><td> فيشر العلمية </td></tr><tr><td> غ هبو 2 4 </td><td> AC20651 - 5000 </td><td> فيشر العلمية </td></tr><tr><td> كلوريد الصوديوم </td><td> BP3581 </td><td> فيشر العلمية </td></tr><tr><td> MgSO 4 </td><td> M80 - 500 </td><td> فيشر العلمية </td></tr></tbody></table>

rnai mediated gene knockdown and transgenesis by microinjection in the necromenic nematode pristionchus pacificus

على الرغم من أنها غير معقولة على نحو متزايد بالنسبة للكائنات نموذج الناشئة للحصول على تسلسل الجينوم تماما ، وكذلك في العمق وظائف الجينات والتحليلات التعبير تدخل الحمض النووي الريبي وtransgenesis مستقرة. تظل محدودة في كثير من الأنواع بسبب التشريح والبيولوجيا الخلوية خاصة الجزيئية للكائن على سبيل المثال ، خارج من انواع معينة المجموعة التي تضم تاج ايليجانس انواع معينة 3 ، تنتقل ستابلي خطوط المعدلة وراثيا في انواع معينة من غير الأنواع لم يتم الإبلاغ عنها في هذه العائلة خادع (النيماتودا) ، مع استثناء من الأسطوانيات البرازية 4 و 5 Pristionchus pacificus. لتسهيل توسيع دور P. pacificus في دراسة التنمية والتطور ، والسلوك 6-7 ، ونحن هنا تصف الأساليب الحالية لاستخدام microinjection الحيوانات المعدلة وراثيا لجعل والجينات التي نهدم رني. مثل الغدد التناسلية لل <em&gt; C. ايليجانس ومعظم الديدان الأخرى ، والغدد التناسلية من P. pacificus هو syncitial وقادرة على دمج الحمض النووي والحمض النووي الريبي في البويضات عند نقلها بواسطة microinjection المباشر. خلافا جيم ايليجانس لكن مستقرة الميراث التحوير والتعبير الجسدي في P. pacificus يتطلب إضافة الحمض النووي الجيني النفس يتفاعل مع endonucleases مكملة لينتهي من الجينات المحورة المستهدفة وعلامات coinjection 5. إضافة الحمض النووي الجيني الناقل مماثل من شرط للتعبير عن التحوير في 4 و الأسطوانيات البرازية في الخلايا الجرثومية من C. ايليجانس. ومع ذلك ، فإنه ليس من الواضح ما اذا كان شرط محدد الحمض النووي للحيوانات &quot;الجينوم الخاصة لأن P. pacificus سوما فعالة جدا في إسكات غير معقدة متعددة الجينات أو أن نسخة خارج الصبغي صفائف في P. pacificus تتطلب متواليات الجينوم لتجميع kinetochore السليم أثناء الانقسام. الهجرة البطنية من (اثنين المسلحةمزدوجة الرحم) المناسل في المخنثين يزيد من تعقيد القدرة على ضخ كل من الغدد التناسلية في الديدان الفردية 8. علينا أن نظهر أيضا استخدام microinjection ضربة قاضية لمتحولة المهيمنة (الدوارة ، tu92) عن طريق حقن المزدوج تقطعت بهم السبل الحمض النووي الريبي (الرنا المزدوج الجديلة) في الحصول على الغدد التناسلية غير المتداول F 1 النسل. خلافا جيم ايليجانس ، ولكن مثل الديدان الخيطية معظم الدول الأخرى ، P. pacificus PS312 ليس تقبلا لرني النظامية عن طريق التغذية وتمرغ وبالتالي يجب أن تدار من قبل الرنا المزدوج الجديلة microinjection في المناسل syncitial. في هذه الدراسة الحالية ، ونأمل أن تصف العملية microinjection اللازمة لتحويل المؤسسة العامة للتقاعد ، المروج EGL - 4 : : GFP مراسل الانصهار وضربة قاضية الأسطوانة المهيمنة PRL - 1 (tu92) متحولة في بروتوكول بالمعلومات بصريا.

Watch this Scientific Journal Video about RNAi Mediated Gene Knockdown and Transgenesis by Microinjection in the Necromenic Nematode Pristionchus pacificus at JoVE.com

RNAi Mediated Gene Knockdown and Transgenesis by Microinjection in the Necromenic Nematode Pristionchus pacificus

في الكائنات النموذج ، ويمكن التلاعب transgenesis ظائف الجينات في حين يمكن رني ضربة قاضية نصوص محددة مرنا 1-2. هذا البروتوكول يهدف لتوضيح التقنيات اللازمة لإدخال الحمض النووي التي تنتقل ستابلي وعابرة RNA المزدوج تقطعت بهم السبل في الخيطية necromenic<em&gt; Pristionchus pacificus</em&gt; للدراسات في البيولوجيا التطورية والإنمائية ، والسلوكية.

وساطة رني ضربة قاضية بواسطة الجينات وTransgenesis Microinjection في نيماتودا Necromenic Pristionchus pacificus</em

Although it is increasingly affordable for emerging model organisms to obtain completely sequenced genomes, further in-depth gene function and expression ...

rnai-mediated-gene-knockdown-transgenesis-microinjection-necromenic

Research

JoVE Journal

Biology

RNAi Mediated Gene Knockdown and Transgenesis by Microinjection in the Necromenic Nematode Pristionchus pacificus

16.4K Views.  California State University. في الكائنات النموذج ، ويمكن التلاعب transgenesis ظائف الجينات في حين يمكن رني ضربة قاضية نصوص محددة مرنا 1-2. هذا البروتوكول يهدف لتوضيح التقنيات اللازمة لإدخال الحمض النووي التي تنتقل ستابلي وعابرة RNA المزدوج تقطعت بهم السبل في الخيطية necromenic Pristionchus pacificus للدر?...

Video: RNAi Mediated Gene Knockdown and Transgenesis by Microinjection in the Necromenic Nematode Pristionchus pacificus

Localized RNAi and Ectopic Gene Expression in the Medicinal Leech

In this video, we show the use of a pneumatic capillary gun for the accurate biolistic delivery of reagents into live tissue. We use the procedure to perturb gene expression patterns in selected segments of leech embryos, leaving the untreated segments as internal controls.
The pneumatic capillary gun can be used to reach internal layers of cells at early stages of development without opening the specimen. As a method for localized introduction of substances into living tissues, the biolistic delivery with the gun has several advantages: it is fast, contact-free and non-destructive. In addition, a single capillary gun can be used for independent delivery of different substances. The delivery region can have lateral dimensions of ~50-150 &#181;m and extends over ~15 &#181;m around the mean penetration depth, which is adjustable between 0 and 50 &#181;m. This delivery has the advantage of being able to target a limited number of cells in a selected location intermediate between single cell knock down by microinjection and systemic knockdown through extracellular injections or by means of genetic approaches.
For knocking down or knocking in the expression of the axon guidance molecule Netrin, which is naturally expressed by some central neurons and in the ventral body wall, but not the dorsal domain, we deliver molecules of dsRNA or plasmid-DNA into the body wall and central ganglia. This procedure includes the following steps: (i) preparation of the experimental setup for a specific assay (adjusting the accelerating pressure), (ii) coating the particles with molecules of dsRNA or DNA, (iii) loading the coated particles into the gun, up to two reagents in one assay, (iv) preparing the animals for the particle delivery, (v) delivery of coated particles into the target tissue (body wall or ganglia), and (vi) processing the embryos (immunostaining, immunohistochemistry and neuronal labeling) to visualize the results, usually 2 to 3 days after the delivery.
When the particles were coated with netrin dsRNA, they caused clearly visible knock-down of netrin expression that only occurred in cells containing particles (usually, 1-2 particles per cell). Particles coated with a plasmid encoding EGFP induced fluorescence in neuronal cells when they stopped in their nuclei.

In this video, we show a procedure for an accurate biolistic delivery of reagents into live tissue with a novel miniature gene gun. We are knocking down the expression of the axon guidance molecule Netrin in leech embryos by delivering molecules of dsRNA into the ventral body wall and ganglia of single segments.

رني المترجمة خارج الرحم والتعبير الجيني في المستنزف الطبية

In this video, we show the use of a pneumatic capillary gun for the accurate biolistic delivery of reagents into live tissue. We use the procedure to ...

Microinjection of Zebrafish Embryos to Analyze Gene Function

One of the advantages of studying zebrafish is the ease and speed of manipulating protein levels in the embryo.  Morpholinos, which are synthetic oligonucleotides with antisense complementarity to target RNAs, can be added to the embryo to reduce the expression of a particular gene product.  Conversely, processed mRNA can be added to the embryo to increase levels of a gene product.  The vehicle for adding either mRNA or morpholino to an embryo is microinjection.  Microinjection is efficient and rapid, allowing for the injection of hundreds of embryos per hour.  This video shows all the steps involved in microinjection.  Briefly, eggs are collected immediately after being laid and lined up against a microscope slide in a Petri dish.  Next, a fine-tipped needle loaded with injection material is connected to a microinjector and an air source, and the microinjector controls are adjusted to produce a desirable injection volume.  Finally, the needle is plunged into the embryo's yolk and the morpholino or mRNA is expelled.

This video shows how morpholino or mRNA can be injected into zebrafish embryos at the one-cell stage to decrease or increase the level of specific gene products during subsequent development.

Microinjection الجنين اسماك الزرد إلى تحليل وظائف الجينات

One of the advantages of studying zebrafish is the ease and speed of manipulating protein levels in the embryo.  Morpholinos, which are synthetic ...

Using an Automated Cell Counter to Simplify Gene Expression Studies: siRNA Knockdown of IL-4 Dependent Gene Expression in Namalwa Cells

The use of siRNA mediated gene knockdown is continuing to be an important tool in studies of gene expression.  siRNA studies are being conducted not only to study the effects of downregulating single genes, but also to interrogate signaling pathways and other complex interaction networks.  These pathway analyses require both the use of relevant cellular models and methods that cause less perturbation to the cellular physiology.  Electroporation is increasingly being used as an effective way to introduce siRNA and other nucleic acids into difficult to transfect cell lines and primary cells without altering the signaling pathway under investigation. There are multiple critical steps to a successful siRNA experiment, and there are ways to simplify the work while improving the data quality at several experimental stages.  To help you get started with your siRNA mediated gene knockdown project, we will demonstrate how to perform a pathway study complete from collecting and counting the cells prior to electroporation through post transfection real-time PCR gene expression analysis.  The following study investigates the role of the transcriptional activator STAT6 in IL-4 dependent gene expression of CCL17 in a Burkitt lymphoma cell line (Namalwa).  The techniques demonstrated are useful for a wide range of siRNA-based experiments on both adherent and suspension cells.  We will also show how to streamline cell counting with the TC10 automated cell counter, how to electroporate multiple samples simultaneously using the MXcell electroporation system, and how to simultaneously assess RNA quality and quantity with the Experion automated electrophoresis system.

This procedure describes a quick and easy workflow to introduce siRNA into difficult to transfect cell lines and follow gene expression by real-time PCR. Use of an automated cell counter, multi-well electroporation plate, and automated electrophoresis station provide quick and reliable results without the need for expensive robotic handling.

باستخدام خلية مكافحة الآلي لتبسيط دراسات التعبير الجيني : ضربة قاضية سيرنا من IL - 4 التعبير الجيني في الخلايا التابعة Namalwa

The use of siRNA mediated gene knockdown is continuing to be an important tool in studies of gene expression.  siRNA studies are being conducted not only ...

Bacterial Delivery of RNAi Effectors: Transkingdom RNAi

RNA interference (RNAi) represents a high effective mechanism for specific inhibition of mRNA expression. Besides its potential as a powerful laboratory tool, the RNAi pathway appears to be promising for therapeutic utilization. For development of RNA interference (RNAi)-based therapies, delivery of RNAi-mediating agents to target cells is one of the major obstacles. A novel strategy to overcome this hurdle is transkingdom RNAi (tkRNAi). This technology uses non-pathogenic bacteria, e.g. Escherichia coli, to produce and deliver therapeutic short hairpin RNA (shRNA) into target cells to induce RNAi. A first-generation tkRNAi-mediating vector, TRIP, contains the bacteriophage T7 promoter for expression regulation of a therapeutic shRNA of interest. Furthermore, TRIP has the Inv locus from Yersinia pseudotuberculosis that encodes invasin, which permits natural noninvasive bacteria to enter &beta;1-integrin-positive mammalian cells and the HlyA gene from Listeria monocytogenes, which produces listeriolysin O. This enzyme allows the therapeutic shRNA to escape from entry vesicles within the cytoplasm of the target cell. TRIP constructs are introduced into a competent non-pathogenic Escherichia coli strain, which encodes T7 RNA polymerase necessary for the T7 promoter-driven synthesis of shRNAs. A well-characterized cancer-associated target molecule for different RNAi strategies is ABCB1 (MDR1/P-glycoprotein, MDR1/P-gp). This ABC-transporter acts as a drug extrusion pump and mediates the "classical" ABCB1-mediated multidrug resistance (MDR) phenotype of human cancer cells which is characterized by a specific cross resistance pattern. Different ABCB1-expressing MDR cancer cells were treated with anti-ABCB1 shRNA expression vector bearing E. coli. This procedure resulted in activation of the RNAi pathways within the cancer cells and a considerable down regulation of the ABCB1 encoding mRNA as well as the corresponding drug extrusion pump. Accordingly, drug accumulation was enhanced in the pristine drug-resistant cancer cells and the MDR phenotype was reversed. By means of this model the data provide the proof-of-concept that tkRNAi is suitable for modulation of cancer-associated factors, e.g. ABCB1, in human cancer cells.

For development of RNA interference (RNAi)-based therapies, a novel strategy was developed, transkingdom RNAi (tkRNAi). This technology uses non-pathogenic bacteria to produce and deliver therapeutic short hairpin RNA (shRNA) into target cells. Here, tkRNAi was successfully applied for reversal of classical ABCB1-mediated multidrug resistance (MDR) of cancer cells.

البكتيرية تسليم المستجيبات رني : Transkingdom رني

RNA interference (RNAi) represents a high effective mechanism for specific inhibition of mRNA expression. Besides its potential as a powerful laboratory ...

Activation of Apoptosis by Cytoplasmic Microinjection of Cytochrome c

Apoptosis, or programmed cell death, is a conserved and highly regulated pathway by which cells die1. Apoptosis can be triggered when cells encounter a wide range of cytotoxic stresses. These insults initiate signaling cascades that ultimately cause the release of cytochrome c from the mitochondrial intermembrane space to the cytoplasm2. The release of cytochrome c from mitochondria is a key event that triggers the rapid activation of caspases, the key cellular proteases which ultimately execute cell death3-4.
The pathway of apoptosis is regulated at points upstream and downstream of cytochrome c release from mitochondria5. In order to study the post-mitochondrial regulation of caspase activation, many investigators have turned to direct cytoplasmic microinjection of holocytochrome c (heme-attached) protein into cells6-9. Cytochrome c is normally localized to the mitochondria where attachment of a heme group is necessary to enable it to activate apoptosis10-11. Therefore, to directly activate caspases, it is necessary to inject the holocytochrome c protein instead of its cDNA, because while the expression of cytochrome c from cDNA constructs will result in mitochondrial targeting and heme attachment, it will be sequestered from cytosolic caspases. Thus, the direct cytosolic microinjection of purified heme-attached cytochrome c protein is a useful tool to mimic mitochondrial cytochrome c release and apoptosis without the use of toxic insults which cause cellular and mitochondrial damage.
In this article, we describe a method for the microinjection of cytochrome c protein into cells, using mouse embryonic fibroblasts (MEFs) and primary sympathetic neurons as examples. While this protocol focuses on the injection of cytochrome c for investigations of apoptosis, the techniques shown here can also be easily adapted for microinjection of other proteins of interest.

Activation of Apoptosis by Cytoplasmic Microinjection of Cytochrome c

In this protocol, we describe the direct cytoplasmic microinjection of cytochrome c protein into fibroblasts and primary sympathetic neurons. This technique allows for the introduction of cytochrome c protein into the cytoplasm of cells and mimics the release of cytochrome c from mitochondria, which occurs during apoptosis.

تفعيل موت الخلايا المبرمج من قبل Microinjection هيولي من السيتوكروم ج</em

Apoptosis, or programmed cell death, is a conserved and highly regulated pathway by which cells die1.  Apoptosis can be triggered when cells encounter a ...

In vitro Reconstitution of the Active T. castaneum Telomerase

Efforts to isolate the catalytic subunit of telomerase, TERT, in sufficient quantities for structural studies, have been met with limited success for more than a decade. Here, we present methods for the isolation of the recombinant Tribolium castaneum TERT (TcTERT) and the reconstitution of the active T. castaneum telomerase ribonucleoprotein (RNP) complex in vitro.
Telomerase is a specialized reverse transcriptase1 that adds short DNA repeats, called telomeres, to the 3' end of linear chromosomes2 that serve to protect them from end-to-end fusion and degradation. Following DNA replication, a short segment is lost at the end of the chromosome3 and without telomerase, cells continue dividing until eventually reaching their Hayflick Limit4. Additionally, telomerase is dormant in most somatic cells5 in adults, but is active in cancer cells6 where it promotes cell immortality7.
The minimal telomerase enzyme consists of two core components: the protein subunit (TERT), which comprises the catalytic subunit of the enzyme and an integral RNA component (TER), which contains the template TERT uses to synthesize telomeres8,9. Prior to 2008, only structures for individual telomerase domains had been solved10,11. A major breakthrough in this field came from the determination of the crystal structure of the active12, catalytic subunit of T. castaneum telomerase, TcTERT1.
Here, we present methods for producing large quantities of the active, soluble TcTERT for structural and biochemical studies, and the reconstitution of the telomerase RNP complex in vitro for telomerase activity assays. An overview of the experimental methods used is shown in Figure 1.

In vitro Reconstitution of the Active T. castaneum Telomerase

Efforts to isolate the catalytic subunit of telomerase, TERT, in sufficient quantities for structural studies, have been met with limited success for more than a decade. Here, we present methods for the isolation of the recombinant Tribolium castaneum TERT (TcTERT) and the reconstitution of the active T. castaneum telomerase ribonucleoprotein (RNP) complex in vitro.

إعادة إعماره في المختبر من أحدث T. castaneum تيلوميراز

Efforts to isolate the catalytic subunit of telomerase, TERT, in sufficient quantities for structural studies, have been met with limited success for more ...

Lentiviral-mediated Knockdown During Ex Vivo Erythropoiesis of Human Hematopoietic Stem Cells

Erythropoiesis is a commonly used model system to study cell differentiation. During erythropoiesis, pluripotent adult human hematopoietic stem cells (HSCs) differentiate into oligopotent progenitors, committed precursors and mature red blood cells 1. This process is regulated for a large part at the level of gene expression, whereby specific transcription factors activate lineage-specific genes while concomitantly repressing genes that are specific to other cell types 2. Studies on transcription factors regulating erythropoiesis are often performed using human and murine cell lines that represent, to some extent, erythroid cells at given stages of differentiation 3-5. However transformed cell lines can only partially mimic erythroid cells and most importantly they do not allow one to comprehensibly study the dynamic changes that occur as cells progress through many stages towards their final erythroid fate. Therefore, a current challenge remains the development of a protocol to obtain relatively homogenous populations of primary HSCs and erythroid cells at various stages of differentiation in quantities that are sufficient to perform genomics and proteomics experiments.
Here we describe an ex vivo cell culture protocol to induce erythroid differentiation from human hematopoietic stem/progenitor cells that have been isolated from either cord blood, bone marrow, or adult peripheral blood mobilized with G-CSF (leukapheresis). This culture system, initially developed by the Douay laboratory 6, uses cytokines and co-culture on mesenchymal cells to mimic the bone marrow microenvironment. Using this ex vivo differentiation protocol, we observe a strong amplification of erythroid progenitors, an induction of differentiation exclusively towards the erythroid lineage and a complete maturation to the stage of enucleated red blood cells. Thus, this system provides an opportunity to study the molecular mechanism of transcriptional regulation as hematopoietic stem cells progress along the erythroid lineage. 
Studying erythropoiesis at the transcriptional level also requires the ability to over-express or knockdown specific factors in primary erythroid cells. For this purpose, we use a lentivirus-mediated gene delivery system that allows for the efficient infection of both dividing and non-dividing cells 7. Here we show that we are able to efficiently knockdown the transcription factor TAL1 in primary human erythroid cells. In addition, GFP expression demonstrates an efficiency of lentiviral infection close to 90%. Thus, our protocol provides a highly useful system for characterization of the regulatory network of transcription factors that control erythropoiesis.

Lentiviral-mediated Knockdown During Ex Vivo Erythropoiesis of Human Hematopoietic Stem Cells

An ex vivo protocol to generate mature human red blood cells from hematopoietic stem/progenitors is described. Additionally we describe an efficient lentiviral-delivery method to knockdown the transcription factor TAL1 in primary erythroid cells. The efficiency of lentivirus mediated gene delivery is demonstrated using GFP expressing viruses.

Lentiviral بوساطة خلال ضربة قاضية السابقين فيفو تكون الكريات الحمر في الإنسان خلايا الجذعية المكونة للدم

Erythropoiesis is a commonly used model system to study cell differentiation. During erythropoiesis, pluripotent adult human hematopoietic stem cells ...

Agrobacterium-Mediated Virus-Induced Gene Silencing Assay In Cotton

Cotton (Gossypium hirsutum) is one of the most important crops worldwide. Considerable efforts have been made on molecular breeding of new varieties. The large-scale gene functional analysis in cotton has been lagged behind most of the modern plant species, likely due to its large size of genome, gene duplication and polyploidy, long growth cycle and recalcitrance to genetic transformation1. To facilitate high throughput functional genetic/genomic study in cotton, we attempt to develop rapid and efficient transient assays to assess cotton gene functions.
Virus-Induced Gene Silencing (VIGS) is a powerful technique that was developed based on the host Post-Transcriptional Gene Silencing (PTGS) to repress viral proliferation2,3. Agrobacterium-mediated VIGS has been successfully applied in a wide range of dicots species such as Solanaceae, Arabidopsis and legume species, and monocots species including barley, wheat and maize, for various functional genomic studies3,4. As this rapid and efficient approach avoids plant transformation and overcomes functional redundancy, it is particularly attractive and suitable for functional genomic study in crop species like cotton not amenable for transformation.
In this study, we report the detailed protocol of Agrobacterium-mediated VIGS system in cotton. Among the several viral VIGS vectors, the tobacco rattle virus (TRV) invades a wide range of hosts and is able to spread vigorously throughout the entire plant yet produce mild symptoms on the hosts5. To monitor the silencing efficiency, GrCLA1, a homolog gene of Arabidopsis Cloroplastos alterados 1 gene (AtCLA1) in cotton, has been cloned and inserted into the VIGS binary vector pYL156. CLA1 gene is involved in chloroplast development6, and previous studies have shown that loss-of-function of AtCLA1 resulted in an albino phenotype on true leaves7, providing an excellent visual marker for silencing efficiency. At approximately two weeks post Agrobacterium infiltration, the albino phenotype started to appear on the true leaves, with 100% silencing efficiency in all replicated experiments. The silencing of endogenous gene expression was also confirmed by RT-PCR analysis. Significantly, silencing could potently occur in all the cultivars we tested, including various commercially grown varieties in Texas. This rapid and efficient Agrobacterium-mediated VIGS assay provides a very powerful tool for rapid large-scale analysis of gene functions at genome-wide level in cotton.

We present the detailed protocol for Agrobacterium-mediated virus-induced gene silencing (VIGS) assay in cotton. The tobacco rattle virus (TRV)-derived VIGS vectors were deployed to induce RNA silencing of cotton GrCLA1, Cloroplastos alterados 1 gene. The albino phenotype caused by silencing GrCLA1 was observed at the seedling stage within 2 weeks after inoculation.

الأجرعية بوساطة الفيروسات إسكات الجينات المستحثة الفحص في القطن

Cotton (Gossypium hirsutum) is one of the most important crops worldwide. Considerable efforts have been made on molecular breeding of new varieties.  The ...

RNAi-mediated Gene Knockdown and In Vivo Diuresis Assay in Adult Female Aedes aegypti Mosquitoes

This video protocol demonstrates an effective technique to knockdown a particular gene in an insect and conduct a novel bioassay to measure excretion rate. This method can be used to obtain a better understanding of the process of diuresis in insects and is especially useful in the study of diuresis in blood-feeding arthropods that are able to take up huge amounts of liquid in a single blood meal. 
This RNAi-mediated gene knockdown combined with an in vivo diuresis assay was developed by the Hansen lab to study the effects of RNAi-mediated knockdown of aquaporin genes on Aedes aegypti mosquito diuresis1. 
The protocol is setup in two parts: the first demonstration illustrates how to construct a simple mosquito injection device and how to prepare and inject dsRNA into the thorax of mosquitoes for RNAi-mediated gene knockdown. The second demonstration illustrates how to determine excretion rates in mosquitoes using an in vivo bioassay.

RNAi-mediated Gene Knockdown and In Vivo Diuresis Assay in Adult Female Aedes aegypti Mosquitoes

In this protocol we combine RNAi-mediated gene silencing with an in vivo diuresis assay to study the effects knockdown of genes of interest has on mosquito fluid excretion.

رني ضربة قاضية بوساطة الجينات و<em&gt; في الجسم الحي</em&gt; فحص إدرار البول في الإناث البالغات<em&gt; الزاعجة المصرية</em&gt; البعوض

This video protocol demonstrates an effective technique to knockdown a particular gene in an insect and conduct a novel bioassay to measure excretion ...

Genome-wide Gene Deletions in Streptococcus sanguinis by High Throughput PCR

Transposon mutagenesis and single-gene deletion are two methods applied in genome-wide gene knockout in bacteria 1,2. Although transposon mutagenesis is less time consuming, less costly, and does not require completed genome information, there are two weaknesses in this method: (1) the possibility of a disparate mutants in the mixed mutant library that counter-selects mutants with decreased competition; and (2) the possibility of partial gene inactivation whereby genes do not entirely lose their function following the insertion of a transposon. Single-gene deletion analysis may compensate for the drawbacks associated with transposon mutagenesis. To improve the efficiency of genome-wide single gene deletion, we attempt to establish a high-throughput technique for genome-wide single gene deletion using Streptococcus sanguinis as a model organism. Each gene deletion construct in S. sanguinis genome is designed to comprise 1-kb upstream of the targeted gene, the aphA-3 gene, encoding kanamycin resistance protein, and 1-kb downstream of the targeted gene. Three sets of primers F1/R1, F2/R2, and F3/R3, respectively, are designed and synthesized in a 96-well plate format for PCR-amplifications of those three components of each deletion construct. Primers R1 and F3 contain 25-bp sequences that are complementary to regions of the aphA-3 gene at their 5' end. A large scale PCR amplification of the aphA-3 gene is performed once for creating all single-gene deletion constructs. The promoter of aphA-3 gene is initially excluded to minimize the potential polar effect of kanamycin cassette. To create the gene deletion constructs, high-throughput PCR amplification and purification are performed in a 96-well plate format. A linear recombinant PCR amplicon for each gene deletion will be made up through four PCR reactions using high-fidelity DNA polymerase. The initial exponential growth phase of S. sanguinis cultured in Todd Hewitt broth supplemented with 2.5% inactivated horse serum is used to increase competence for the transformation of PCR-recombinant constructs. Under this condition, up to 20% of S. sanguinis cells can be transformed using ~50 ng of DNA. Based on this approach, 2,048 mutants with single-gene deletion were ultimately obtained from the 2,270 genes in S. sanguinis excluding four gene ORFs contained entirely within other ORFs in S. sanguinis SK36 and 218 potential essential genes. The technique on creating gene deletion constructs is high throughput and could be easy to use in genome-wide single gene deletions for any transformable bacteria.

Genome-wide Gene Deletions in Streptococcus sanguinis by High Throughput PCR

An efficient genome-wide single gene mutation method has been established using Streptococcus sanguinis as a model organism. This method has achieved via high throughput recombinant PCRs and transformations.

حذوفات الجينات في الجينوم على نطاق<em&gt; العقدية الدم</em&gt; من جانب PCR إنتاجية عالية

Transposon  mutagenesis and single-gene deletion are two methods applied in genome-wide  gene knockout in bacteria 1,2. Although transposon mutagenesis is ...