עבודה זו נתמכה על ידי קרנות זרע מאוניברסיטת פיטסבורג NIH מענק AG028977 ל אלף

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	<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=.">.</a> Wormbook. , 1-15 (2006).</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. , (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 Cell Biol. 48, 451-482 (1995).</li><li>Mello, C. C., Kramer, J. 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U., Schnabel, H., Schnabel, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ballistic+transformation+of+Caenorhabditis+elegans.">Ballistic transformation of Caenorhabditis elegans.</a> Gene. 229, 31-35 (1999).</li><li>Berezikov, E., Bargmann, C. I., Plasterk, R. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Homologous+gene+targeting+in+Caenorhabditis+elegans+by+biolistic+transformation.">Homologous gene targeting in Caenorhabditis elegans by biolistic transformation.</a> Nucleic Acids Res. 32, e40-e40 (2004).</li><li>Maduro, M., Pilgrim, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+and+cloning+of+unc-119,+a+gene+expressed+in+the+Caenorhabditis+elegans+nervous+system.">Identification and cloning of unc-119, a gene expressed in the Caenorhabditis elegans nervous system.</a> Genetics. 141, 977-988 (1995).</li><li>Riddle, D. L., Swanson, M. M., Albert, P. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interacting+genes+in+nematode+dauer+larva+formation.">Interacting genes in nematode dauer larva formation.</a> Nature. 290, 668-671 (1981).</li><li>Maduro, M., Pilgrim, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Conservation+of+function+and+expression+of+unc-119+from+two+Caenorhabditis+species+despite+divergence+of+non-coding+DNA.">Conservation of function and expression of unc-119 from two Caenorhabditis species despite divergence of non-coding DNA.</a> Gene. 183, 77-85 (1996).</li><li>Ferguson, A. A., Fisher, A. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Retrofitting+ampicillin+resistant+vectors+by+recombination+for+use+in+generating+C.+elegans+transgenic+animals+by+bombardment.">Retrofitting ampicillin resistant vectors by recombination for use in generating C. elegans transgenic animals by bombardment.</a> Plasmid. 62, 140-145 (2009).</li><li>Zhang, Y., Nash, L., Fisher, A. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+simplified,+robust,+and+streamlined+procedure+for+the+production+of+C.+elegans+transgenes+via+recombineering.">A simplified, robust, and streamlined procedure for the production of C. elegans transgenes via recombineering.</a> BMC Dev Biol. 8, 119-119 (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 Cell Biol. 48, 3-30 (1995).</li><li>Sulston, J. E., Horvitz, H. R., 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=.">.</a> The nematode, Caenorhabditis elegans. , 587-606 (1988).</li><li>Sivamani, E., DeLong, R. K., Qu, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Protamine-mediated+DNA+coating+remarkably+improves+bombardment+transformation+efficiency+in+plant+cells.">Protamine-mediated DNA coating remarkably improves bombardment transformation efficiency in plant cells.</a> Plant Cell Rep. 28, 213-221 (2009).</li><li>Johnston, S. 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אין ניגודי אינטרסים הכריז.

הפגזה Biolistic היא שיטה פשוטה להציג דנ&quot;א זר לתוך אורגניזמים רבים, כולל ג elegans 1,5,6,7,16. הוא מסתמך על חלקיקי זהב ויצרו מורכבות עם ה-DNA בנוכחות CaCl 2. פוליאמינים קטיוני, כגון spermidine, להגן על ה-DNA מן השפלה nuclease in vivo. מאז spermidine הוא מולקולה יציב, חשוב לאחסן אותו aliquots קטן -20 ° C, ולהפוך את הפתרון הנכון לפני ביצוע הפצצה. כפי שתואר בפרוטוקול הפגזה, protamine יכול לשמש במקום spermidine להעביר דנ&quot;א זר 15. Protamine יש את היתרון של להיות יציבה יותר בטמפרטורת החדר להיות אבקת במקום נוזל צמיג. הגן-119 UNC ההצלה ניתן להציב גם על פלסמיד זהה transgene או על פלסמיד נפרד כי הוא מעורבב עם transgene לפני ציפוי חלקיקי זהב cis. בעוד ערבוב של אחד או יותר פלסמידים הוא מוצלח בדרך כלל, אנו ואחרים מצאו כי ההפצצה של תולעים עם פלסמידים מרובים יכולים ליצור חיות טרנסגניות נושאים מסוימים, אך לא כולם פלסמידים 6,11. כדי להקל על הצבת גן UNC-119 על transgene הפלסמיד, אנו לאחרונה תיאר באמצעות פרוטוקול הומולוגיים רקומבינציה להכניס את הגן 119 UNC לתוך הגן התנגדות אמפיצילין של כמעט כל פלסמידים 11. יתר על כן, כדי להקל על transgenes נע זן DP38 לתוך זנים תולעת חסרת המוטציה UNC-119, יש לנו גם שנוצר פלסמיד עם UNC-119 התמזגו mCherry 11. הקרינה הפאן העצבית mCherry לאחר מכן ניתן להשתמש כדי לעקוב אחר נוכחות של transgene במגוון רחב של רקע גנטי 11. Transgenes כמה יכול להיות קשה לזהות אחרי הפגזה בשל ביטוי חלש או ביטוי בשלב מסוים. הנוכחות של transgene ניתן לאמת לעתים קרובות באמצעות שימוש PCR באמצעות תולעים מהונדס. עבור transgenes עם הביטוי חלש, ביצוע הפצצות נוספות יכולה להוביל לזיהוי של קווים עם ביטוי חזק יותר. לחלופין, את השימוש במתחם או מיקרוסקופ confocal לעתים קרובות יכול לעזור לדמיין את הביטוי של חלבוני ניאון.

The volume for a solution in, <a href="http://www.jove.com/video/2090">Generation of Transgenic C. elegans by Biolistic Transformation</a>, was incorrect.

Erratum: Generation of Transgenic C. elegans by Biolistic Transformation

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<td>Gold particles</td>
<td>&nbsp;</td>
<td>Inbio gold</td>
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<td>1micron</td>
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<td>Midiprep kit</td>
<td>&nbsp;</td>
<td>Qiagen</td>
<td>12143</td>
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<td>Spermidine</td>
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<td>Sigma</td>
<td>S4139</td>
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<td>Protamine</td>
<td>&nbsp;</td>
<td>Sigma </td>
<td> P4505</td>
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<td>Macrocarriers</td>
<td>&nbsp;</td>
<td>Biorad</td>
<td>165-2335</td>
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<td>&nbsp;</td>
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<td>165-2330</td>
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<td>&nbsp;</td>
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<td>N1638</td>
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generation of transgenic c. elegans by biolistic transformation

מספר מעבדות באמצעות C. חינם נמטודות חיים elegans הוא הולך וגדל במהירות. הפופולריות של הדגם הזה ביולוגי מיוחסת זמן הדור מהירה תוחלת חיים קצרה, תחזוקה קלה וזולה, רצף גנום מלא, מערך של RNAi משאבים בעלי חיים מוטציה. בנוסף, ניתוח של C. elegans הגנום גילה דמיון רב בין תולעים חוליות גבוהה, אשר טוען כי מחקר תולעים יכול להיות נספח חשוב מחקרים שבוצעו בעכברים כולו או תאים בתרבית. חלק חזק וחשוב של מחקר תולעת הוא היכולת להשתמש חיות טרנסגניות ללמוד לוקליזציה גן ותפקוד. בעלי חיים מהונדס ניתן ליצור גם באמצעות microinjection של germline התולעת או באמצעות הפצצה biolistic. הפצצה היא טכניקה חדשה והיא מוכרת פחות למספר מעבדות. כאן אנו מתארים פרוטוקול פשוט לייצר תולעים מהונדס בהפצצות biolistic עם חלקיקי זהב באמצעות Bio-Rad PDS-1000 המערכת. בהשוואה microinjection דנ&quot;א לתוך אנדרוגינוס germline, פרוטוקול זה יש את היתרון של לא דורש כישורים מיוחדים ממפעיל לגבי זיהוי האנטומיה תולעת או ביצוע microinjection. יתר על הקווים מהונדס מרובים מתקבלים בדרך כלל הפגזה אחת. כמו כן, בניגוד microinjection, הפגזה biolistic מייצרת חיות טרנסגניות עם שני מערכים extrachromosomal ו transgenes משולב. היכולת לקבל קווי מהונדס משולב יכול למנוע את השימוש של פרוטוקולים מוטגניות לשלב דנ&quot;א זר. לסיכום, הפגזה biolistic יכולה להיות שיטה אטרקטיבי עבור הדור של חיות טרנסגניות, במיוחד עבור החוקרים לא מעוניין להשקיע את הזמן והמאמץ הדרושים כדי להיות מיומנים microinjection.

Watch this Scientific Journal Video about Generation of Transgenic C. elegans by Biolistic Transformation at JoVE.com

Generation of Transgenic C. elegans by Biolistic Transformation

תולעים טראנסגנטי משמשים בדרך כלל<em&gt; ג elegans</em&gt; מחקר. המתואר הוא פרוטוקול פשוט, אך יעיל, להציג transgenes לתוך תולעים באמצעות הפצצה biolistic עם DNA מצופה חלקיקי זהב. המאמץ הכרוך ואת התוצאות של הפצצה להשוות לטובה עם microinjection עבור הדור של חיות טרנסגניות.

דור טראנסגנטי ג elegans על ידי שינוי Biolistic

The number of laboratories using the free living nematode C. elegans is rapidly growing. The popularity of this biological model is attributed to a rapid ...

generation-of-transgenic-c-elegans-by-biolistic-transformation

Universidad San Sebastian

Research

JoVE Journal

Biology

Generation of Transgenic C. elegans by Biolistic Transformation

21.8K Views.  University of Pittsburgh. תולעים טראנסגנטי משמשים בדרך כלל ג elegans מחקר. המתואר הוא פרוטוקול פשוט, אך יעיל, להציג transgenes לתוך תולעים באמצעות הפצצה biolistic עם DNA מצופה חלקיקי זהב. המאמץ הכרוך ואת התוצאות של הפצצה להשוות לטובה עם microinjection עבור הדור של חיות טרנסגניות.

Video: Generation of Transgenic C. elegans by Biolistic Transformation

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.

הדור של Stable טראנסגנטי C. elegans שימוש Microinjection

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

Paradigms for Pharmacological Characterization of C. elegans Synaptic Transmission Mutants

The nematode, Caenorhabditis elegans, has become an expedient model for studying neurotransmission. C. elegans is unique among animal models, as the anatomy and connectivity of its nervous system has been determined from electron micrographs and refined by pharmacological assays. In this video, we describe how two complementary neural stimulants, an acetylcholinesterase inhibitor, called aldicarb, and a gamma-aminobutyric acid (GABA) receptor antagonist, called pentylenetetrazole (PTZ), may be employed to specifically characterize signaling at C. elegans neuromuscular junctions (NMJs) and facilitate our understanding of antagonistic neural circuits.
Of 302 C. elegans neurons, nineteen GABAergic D-type motor neurons innervate body wall muscles (BWMs), while four GABAergic neurons, called RMEs, innervate head muscles. Conversely, thirty-nine motor neurons express the excitatory neurotransmitter, acetylcholine (ACh), and antagonize GABA transmission at BWMs to coordinate locomotion. The antagonistic nature of GABAergic and cholinergic motor neurons at body wall NMJs was initially determined by laser ablation and later buttressed by aldicarb exposure. Acute aldicarb exposure results in a time-course or dose-responsive paralysis in wild-type worms. Yet, loss of excitatory ACh transmission confers resistance to aldicarb, as less ACh accumulates at worm NMJs, leading to less stimulation of BWMs. Resistance to aldicarb may be observed with ACh-specific or general synaptic function mutants. Consistent with antagonistic GABA and ACh transmission, loss of GABA transmission, or a failure to negatively regulate ACh release, confers hypersensitivity to aldicarb. Although aldicarb exposure has led to the isolation of numerous worm homologs of neurotransmission genes, aldicarb exposure alone cannot efficiently determine prevailing roles for genes and pathways in specific C. elegans motor neurons. For this purpose, we have introduced a complementary experimental approach, which uses PTZ.
Neurotransmission mutants display clear phenotypes, distinct from aldicarb-induced paralysis, in response to PTZ. Wild-type worms, as well as mutants with specific inabilities to release or receive ACh, do not show apparent sensitivity to PTZ. However, GABA mutants, as well as general synaptic function mutants, display anterior convulsions in a time-course or dose-responsive manner. Mutants that cannot negatively regulate general neurotransmitter release and, thus, secrete excessive amounts of ACh onto BWMs, become paralyzed on PTZ. The PTZ-induced phenotypes of discrete mutant classes indicate that a complementary approach with aldicarb and PTZ exposure paradigms in C. elegans may accelerate our understanding of neurotransmission. Moreover, videos demonstrating how we perform pharmacological assays should establish consistent methods for C. elegans research.

This video demonstrates how to employ two neural stimulants, aldicarb and pentylenetetrazole (PTZ), in complementary ways to study synaptic function in the nematode, C. elegans. This complementary approach may also be used to shed light on evolutionarily conserved mechanisms for modulating neuronal synchrony and has implications for epilepsy and seizures.

פרדיגמות אפיון תרופתי של C. elegans מוטאנטים הילוכים Synaptic

The nematode, Caenorhabditis elegans, has become an expedient model for studying neurotransmission. C. elegans is unique among animal models, as the ...

Generation of RNA/DNA Hybrids in Genomic DNA by Transformation using RNA-containing Oligonucleotides

Synthetic short nucleic acid polymers, oligonucleotides (oligos), are the most functional and widespread tools of molecular biology. Oligos can be produced to contain any desired DNA or RNA sequence and can be prepared to include a wide variety of base and sugar modifications. Moreover, oligos can be designed to mimic specific nucleic acid alterations and thus, can serve as important tools to investigate effects of DNA damage and mechanisms of repair. We found that Thermo Scientific Dharmacon RNA-containing oligos with a length between 50 and 80 nucleotides can be particularly suitable to study, in vivo, functions and consequences of chromosomal RNA/DNA hybrids and of ribonucleotides embedded into DNA. RNA/DNA hybrids can readily form during DNA replication, repair and transcription, however, very little is known about the stability of RNA/DNA hybrids in cells and to which extent these hybrids can affect the genetic integrity of cells. RNA-containing oligos, therefore, represent a perfect vector to introduce ribonucleotides into chromosomal DNA and generate RNA/DNA hybrids of chosen length and base composition. Here we present the protocol for the incorporation of ribonucleotides into the genome of the eukaryotic model system yeast /Saccharomyces cerevisiae/. Yet, our lab has utilized Thermo Scientific Dharmacon RNA-containing oligos to generate RNA/DNA hybrids at the chromosomal level in different cell systems, from bacteria to human cells.

This work shows how to form an RNA/DNA hybrid at the chromosomal level and reveal transfer of genetic information from RNA to genomic DNA in yeast cells.

הדור של RNA / DNA כלאיים ב-DNA הגנום על ידי טרנספורמציה באמצעות RNA המכיל oligonucleotides

Synthetic short nucleic acid polymers, oligonucleotides (oligos), are the most functional and widespread tools of molecular biology. Oligos can be ...

Basic Caenorhabditis elegans Methods: Synchronization and Observation

Research into the molecular and developmental biology of the nematode Caenorhabditis elegans was begun in the early seventies by Sydney Brenner and it has since been used extensively as a model organism 1. C. elegans possesses key attributes such as simplicity, transparency and short life cycle that have made it a suitable experimental system for fundamental biological studies for many years 2. Discoveries in this nematode have broad implications because many cellular and molecular processes that control animal development are evolutionary conserved 3.
C. elegans life cycle goes through an embryonic stage and four larval stages before animals reach adulthood. Development can take 2 to 4 days depending on the temperature. In each of the stages several characteristic traits can be observed. The knowledge of its complete cell lineage 4,5 together with the deep annotation of its genome turn this nematode into a great model in fields as diverse as the neurobiology 6, aging 7,8, stem cell biology 9 and germ line biology 10. 
An additional feature that makes C. elegans an attractive model to work with is the possibility of obtaining populations of worms synchronized at a specific stage through a relatively easy protocol. The ease of maintaining and propagating this nematode added to the possibility of synchronization provide a powerful tool to obtain large amounts of worms, which can be used for a wide variety of small or high-throughput experiments such as RNAi screens, microarrays, massive sequencing, immunoblot or in situ hybridization, among others. 
Because of its transparency, C. elegans structures can be distinguished under the microscope using Differential Interference Contrast microscopy, also known as Nomarski microscopy. The use of a fluorescent DNA binder, DAPI (4',6-diamidino-2-phenylindole), for instance, can lead to the specific identification and localization of individual cells, as well as subcellular structures/defects associated to them.

Basic Caenorhabditis elegans Methods: Synchronization and Observation

The easiness of maintaining and propagating the nematode C. elegans make it a nice model organism to work with. The possibility of synchronizing worms allows the work with a significant amount of subjects at the same developmental stage, what facilitates the study of one particular process in many animals.

בסיסי<em&gt; Caenorhabditis elegans</em&gt; שיטות: סנכרון תצפית

Research into the molecular and developmental biology of the nematode Caenorhabditis elegans was begun in the early seventies by Sydney Brenner and it has ...

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.

Assay Chemotaxis סי אלגנס

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

A Method for Culturing Embryonic C. elegans Cells

C. elegans is a powerful model system, in which genetic and molecular techniques are easily applicable. Until recently though, techniques that require direct access to cells and isolation of specific cell types, could not be applied in C. elegans. This limitation was due to the fact that tissues are confined within a pressurized cuticle which is not easily digested by treatment with enzymes and/or detergents. Based on early pioneer work by Laird Bloom, Christensen and colleagues 1 developed a robust method for culturing C. elegans embryonic cells in large scale. Eggs are isolated from gravid adults by treatment with bleach/NaOH and subsequently treated with chitinase to remove the eggshells. Embryonic cells are then dissociated by manual pipetting and plated onto substrate-covered glass in serum-enriched media. Within 24 hr of isolation cells begin to differentiate by changing morphology and by expressing cell specific markers. C. elegans cells cultured using this method survive for up 2 weeks in vitro and have been used for electrophysiological, immunochemical, and imaging analyses as well as they have been sorted and used for microarray profiling.

A Method for Culturing Embryonic C. elegans Cells

We describe here a revised protocol for large-scale culture of embryonic C. elegans cells. Embryonic C. elegans cells cultured in vitro using this method, appear to differentiate and recapitulate the expression of genes in a cell specific manner. Techniques that require direct access to the cells or isolation of specific cell types from the other tissues can be applied on C. elegans cultured cells.

שיטה לCulturing עוברי<em&gt; ג elegans</em&gt; תאים

C. elegans is a powerful model system, in which genetic and molecular techniques are easily applicable. Until recently though, techniques that require ...

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 &quot;Freeze-Cracking&quot;

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

נוגדן מכתים ב<em&gt; ג Elegans</em&gt; שימוש &quot;Freeze-פיצוח&quot;

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

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.

דגם אנוקסיה רעב לאיסכמיה / reperfusion ב<em&gt; ג elegans</em

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

Culturing Caenorhabditis elegans in Axenic Liquid Media and Creation of Transgenic Worms by Microparticle Bombardment

In this protocol, we present the required materials, and the procedure for making modified&#160;C. elegans&#160;Habituation and Reproduction media (mCeHR). Additionally, the steps for exposing and acclimatizing C. elegans grown on E. coli to axenic liquid media are described. Finally, downstream experiments that utilize axenic C. elegans illustrate the benefits of this procedure. The ability to analyze and determine C. elegans&#160;nutrient requirement was illustrated by growing N2 wild type worms in axenic liquid media with varying heme concentrations. This procedure can be replicated with other nutrients to determine the optimal concentration for worm growth and development or, to determine the toxicological effects of drug treatments. The effects of varied heme concentrations on the growth of wild type worms were determined through qualitative microscopic observation and by quantitating the number of worms that grew in each heme concentration. In addition, the effect of varied nutrient concentrations can be assayed by utilizing worms that express fluorescent sensors that respond to changes in the nutrient of interest. Furthermore, a large number of worms were easily produced for the generation of transgenic C. elegans using microparticle bombardment.

Culturing Caenorhabditis elegans in Axenic Liquid Media and Creation of Transgenic Worms by Microparticle Bombardment

C. elegans is usually grown on solid agar plates or in liquid cultures seeded with E. coli. To prevent bacterial byproducts from confounding toxicological and nutritional studies, we utilized an axenic liquid medium, CeHR, to grow and synchronize a large number of worms for a range of downstream applications.

Culturing<em&gt; Elegans Caenorhabditis</em &gt; בAxenic נוזלית מדיה ובריאה של תולעים מהונדסים ידי microparticle הפצצה

In this protocol, we present the required materials, and the procedure for making modified&#160;C. elegans&#160;Habituation and Reproduction media ...

Generation of Transgenic Hydra by Embryo Microinjection

As a member of the phylum Cnidaria, the sister group to all bilaterians, Hydra can shed light on fundamental biological processes shared among multicellular animals. Hydra is used as a model for the study of regeneration, pattern formation, and stem cells. However, research efforts have been hampered by lack of a reliable method for gene perturbations to study molecular function. The development of transgenic methods has revitalized the study of Hydra biology1. Transgenic Hydra allow for the tracking of live cells, sorting to yield pure cell populations for biochemical analysis, manipulation of gene function by knockdown and over-expression, and analysis of promoter function. Plasmid DNA injected into early stage embryos randomly integrates into the genome early in development. This results in hatchlings that express transgenes in patches of tissue in one or more of the three lineages (ectodermal epithelial, endodermal epithelial, or interstitial). The success rate of obtaining a hatchling with transgenic tissue is between 10% and 20%. Asexual propagation of the transgenic hatchling is used to establish a uniformly transgenic line in a particular lineage. Generating transgenic Hydra is surprisingly simple and robust, and here we describe a protocol that can be easily implemented at low cost.

Generation of Transgenic Hydra by Embryo Microinjection

Stably transgenic Hydra are made by microinjection of plasmid DNA into embryos followed by random genomic integration and asexual propagation to establish a uniform line. Transgenic Hydra are used to track cell movements, overexpress genes, study promoter function, or knock down gene expression using RNAi.