עבודה זו נתמכה על ידי המכונים הלאומיים לבריאות מענק NIDDK (K01DK092320) ומימון אתחול מתוך מחלקת ילדים בבית הספר לרפואה של אוניברסיטת טקסס מקגוורן.

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The authors declare that they have no competing financial interests.

מיקוד כִּליַת רֵאשִׁית לפתח עוברי Xenopus מסתמכת על זיהוי הזרקת blastomere הנכון. הזרקה של blastomere V2 של עוברים 8 תאים מטרות כִּליַת רֵאשִׁית שמאל 18. זה משאיר את כִּליַת רֵאשִׁית התקינה הנגדית כמו שליטה פנימית. אם morpholino מציאה או ביטוי יתר RNA משמש המשנה את ההתפתחות בכלי?...

הכליה העוברית Xenopus, את כִּליַת רֵאשִׁית, הוא מודל טוב ללימוד פיתוח כליות ומחלות. עובר לפתח חיצוני, הם גדולים, יכולים להיות מיוצרים בכמויות גדולות, והם מניפולציות בקלות באמצעות microinjection או הליכים כירורגיים. בנוסף, הגנים לפיקוח על בניית כליות אצל יונקים ודו-חיים הם משומר. כליות יונקות להתקדם דרך שלושה שלבים: כִּליַת רֵאשִׁית, הכליה, ו metanephros 1, בעוד דו חיים עובריים כִּליַת רֵאשִׁית ודו-חי בוגרים יש metanephros. יחידת הסינון הבסיסית של צורות כליות אלה היא נפרון, ושניהם יונקים ודו-חיים דורשים את אותה מפלי איתות ואירועים אינדוקטיביים לעבור nephrogenesis 2, 3. כִּליַת רֵאשִׁית Xenopus מכילה נפרון בודד מורכב הפרוקסימלי, ביניים, דיסטלי וחיבור tubules, וכן glomus (מקביל ל glomerulus היונק) 1, 4-6 (איור 1 </strאונג&gt;). הווה נפרון הבודד, הגדול Xenopus כִּליַת רֵאשִׁית הופך אותו מתאים כמודל פשוט לחקר הגנים המעורבים בתהליכי פיתוח כליות ומחלות. מפות גורל התא הוקמו עבור עוברי Xenopus מוקדם, והם זמינים באופן חופשי באינטרנט ב Xenbase 7-11. כאן אנו מתארים טכניקה microinjection של קליעים נותבים השושלת למקד את כִּליַת רֵאשִׁית Xenopus פיתוח, אם כי באותה טכניקה ניתן להתאים למקד ברקמות אחרות כגון הלב או העיניים. קליעים נותבים השושלת הם תוויות (כולל צבעים חיוניים, dextrans שכותרתו fluorescently, אנזימים לגילוי histochemically, ו mRNA קידוד חלבוני ניאון) כי ניתן להזריק לתוך blastomere מוקדם, המאפשר הדמיה של הצאצאים של התא במהלך ההתפתחות. פרוטוקול זה מנצל mRNA MEM-RFP, קרום קידוד ממוקד חלבון פלואורסצנטי אדום 12, כמו נותב השושלת. טק microinjection הממוקדniques עבור בלסטומרים בודדים עוברים 4 ו 8 תאים המתואר כאן יכול להיות מנוצל להזרקה עם morpholinos להפיל ביטוי גנים, או עם RNA אקסוגני overexpress הגן של עניין. באמצעות הזרקה לתוך blastomere הגחון, הצמחי, בעיקר כִּליַת רֵאשִׁית של העובר תהיה ממוקדת, עוזבת את כִּליַת רֵאשִׁית הנגדית כביקורת התפתחותית. שיתוף ההזרקה נותב מוודאת כי blastomere הנכון הוזרק, ומופעים אשר רקמות בעובר נבעו blastomere המוזרק, אימות מיקוד של כִּליַת רֵאשִׁית. Immunostaining של כִּליַת רֵאשִׁית מאפשר הדמיה של מידת הצלחה של tubules pronephric היה ממוקד. תופעות התבטאות יתר ו מציאה אז יכול להיות הבקיע נגד הצד הנגדי של העובר, אשר משמש כביקורת התפתחותי, והוא יכול לשמש כדי לחשב את מדד pronephric 13. הזמינות של מפות גורל התא מאפשרת טכניקת microinjection ממוקדת זה כדי לשמש יעד רקמות othאה מאשר כִּליַת רֵאשִׁית, ואת שיתוף ההזרקה נותב ניאון מאפשר microinjection המתמקדת בכל רקמות להיות מאומתת לפני הניתוח. במהלך microinjection העובר, טמפרטורה התפתחותי צריכה להיות מוסדרת בחוזקה, בהתחשב בכך את קצב התפתחות Xenopus תלוי מאוד עליו 14. עובר צריך להיות מודגרות בטמפרטורות קרירות (14 - 16 מעלות צלזיוס) במשך 4 ו זריקות 8 תאים כי זמן הפיתוח הוא האטה. בגיל 22 ° C, זמן הפיתוח מ -1 הבמה (תא 1) לביים 3 (4 תאים) הוא כ 2 שעות, תוך 16 ° C זמן הפיתוח לשלב 3 הוא כ 4 שעות. זה לוקח בערך 15 דקות לסיום מעובר 4 תאים לעובר 8 תאים (שלב 4) על 22 מעלות צלזיוס, אבל לוקח בערך 30 דקות על 16 מעלות צלזיוס. באופן דומה, על 22 מעלות צלזיוס, זה לוקח רק 30 דקות עבור עובר 8 תאים כדי להתקדם עובר 16 תאים (שלב 5). הפעם הוא עלה ל 45 דקות ב 16 מעלות צלזיוס. הrefore, כדאי להאט את קצב הפיתוח של עוברים כדי לאפשר מספיק זמן עבור זריקות בשלב 8 תאים לפני העוברים להתקדם לשלב 16 תאים. בנוסף, בטמפרטורות צמיחה יכולות להיות מווסתות כדי להאיץ או להאט התפתחות עוברית עד הכליות פתחו באופן מלא. האפידרמיס של עובר ראשן שלבית Xenopus הוא יחסית שקוף, המאפשר הדמיה קלה של כִּליַת רֵאשִׁית בפיתוח בלי דיסקציה או סליקה של הרקמה 15. בשל השקיפות היחסית של עוברי Xenopus, הדמיה תא חי הוא גם אפשרי 16,17. כל הר immunostaining לדמיין את כִּליַת רֵאשִׁית אפשרי עם נוגדנים נקבע כי התווית הפרוקסימלי, ביניים, דיסטלי ו tubules חיבור של שלב 38 - 40 עוברים המאפשרים הערכת התפתחות pronephric ממוקד לאחר מניפולציה של ביטוי גנים העוברים Xenopus 18-20.

<table><tbody><tr><td>Sodium chloride</td><td>Fisher</td><td>S271-3</td><td></td></tr><tr><td>Potassium chloride</td><td>Fisher</td><td>P217-500</td><td></td></tr><tr><td>Magnesium sulfate&amp;nbsp;</td><td>Fisher</td><td>M63-500</td><td></td></tr><tr><td>Calcium chloride</td><td>Fisher</td><td>C79-500</td><td></td></tr><tr><td>HEPES</td><td>Fisher</td><td>BP310-500</td><td></td></tr><tr><td>EDTA</td><td>Fisher</td><td>S311-500</td><td></td></tr><tr><td>Gentamycin solution, 50 mg/ml</td><td>Amresco</td><td>E737-20ML</td><td></td></tr><tr><td>L-Cysteine, 99%+</td><td>Acros Organics</td><td>52-90-4</td><td></td></tr><tr><td>Ficoll</td><td>Fisher</td><td>BP525-100</td><td></td></tr><tr><td>100 mm x 15 mm Petri dish</td><td>Fisher</td><td>FB0875712</td><td></td></tr><tr><td>Mini Fridge II</td><td>Boekel</td><td>260009</td><td>Benchtop incubator for embryos.</td></tr><tr><td>Gap43-RFP plasmid</td><td></td><td></td><td>For making tracer RNA. Ref: Davidson &lt;em&gt;et al.&lt;/em&gt;, 2006.</td></tr><tr><td>Rhodamine dextran, 10,000 M.W.</td><td>Invitrogen</td><td>D1817</td><td>Tracer.</td></tr><tr><td>Molecular biology grade, USP sterile purified water</td><td>Corning</td><td>46-000-CI</td><td></td></tr><tr><td>7&quot; Drummond replacement tubes</td><td>Drummond</td><td>3-000-203-G/XL</td><td>Microinjection needles.</td></tr><tr><td>Needle puller</td><td>Sutter Instruments</td><td>P-30</td><td></td></tr><tr><td>Fine forceps</td><td>Dumont</td><td>11252-30</td><td>For breaking microinjection needle tip.</td></tr><tr><td>Nanoject II</td><td>Drummond</td><td>3-000-204</td><td>Microinjector.</td></tr><tr><td>Mineral oil, heavy</td><td>Fisher</td><td>CAS 8042-47-5</td><td>Oil for needles.</td></tr><tr><td>27 G Monoject hypodermic needle</td><td>Covidien</td><td>8881200508</td><td>For loading mineral oil into microinjection needle.</td></tr><tr><td>5 ml Luer-Lok syringe</td><td>BD</td><td>309646</td><td>For loading mineral oil into microinjection needle.</td></tr><tr><td>60 mm x 15 mm Petri dish</td><td>Fisher</td><td>FB0875713A</td><td></td></tr><tr><td>800 micron Polyester mesh</td><td>Small Parts</td><td>CMY-0800-C</td><td></td></tr><tr><td>Transfer pipets</td><td>Fisher</td><td>13-711-7M</td><td>For transferring embryos. Cut off the tip so that the embryos are easily taken up by the pipette.</td></tr><tr><td>6-well cell culture plate</td><td>Nest Biotechnology</td><td></td><td></td></tr><tr><td>MOPS</td><td>Fisher</td><td>BP308-500</td><td></td></tr><tr><td>EGTA</td><td>Acros Organics</td><td>67-42-5</td><td></td></tr><tr><td>Formaldehyde</td><td>Fisher</td><td>BP531-500</td><td></td></tr><tr><td>15 mm x 45 mm Screw thread vial</td><td>Fisher</td><td>03-339-25B</td><td>For fixing, staining, and storing embryos.</td></tr><tr><td>24-well cell Culture plate</td><td>Nest Biotechnology</td><td></td><td></td></tr><tr><td>Benzocaine</td><td>Spectrum</td><td>BE130</td><td></td></tr><tr><td>Ethanol</td><td>Fisher</td><td>BP2818-4</td><td></td></tr><tr><td>Methanol</td><td>Fisher</td><td>A412-4</td><td></td></tr><tr><td>Phosphate buffered saline (PBS) 1x powder</td><td>Fisher</td><td>BP661-50</td><td></td></tr><tr><td>Bovine serum albumen</td><td>Fisher</td><td>BP1600-100</td><td></td></tr><tr><td>Triton X-100</td><td>Fisher</td><td>BP151-500</td><td></td></tr><tr><td>3D Mini rocker, model 135</td><td>Denville Scientific</td><td>57281</td><td></td></tr><tr><td>Goat serum, New Zealand origin</td><td>Invitrogen</td><td>16210064</td><td></td></tr><tr><td>Sodium azide</td><td>Fisher</td><td>S227I-25</td><td></td></tr><tr><td>Monoclonal 3G8 antibody</td><td>European Xenopus Resource Centre</td><td></td><td>Primary antibody to label proximal tubules.</td></tr><tr><td>Monoclonal 4A6 antibody</td><td>European Xenopus Resource Centre</td><td></td><td>Primary antibody to label intermediate, distal and connecting tubules.</td></tr><tr><td>anti-RFP pAb, purified IgG/rabbit</td><td>MBL</td><td>PM005</td><td>Primary antibody to label Gap43-RFP tracer.</td></tr><tr><td>Alexa Fluor 488 goat anti-mouse IgG</td><td>Life Technologies</td><td>A11001</td><td>Secondary antibody to label kidney tubules.</td></tr><tr><td>Alexa Fluor 555 goat anti-rabbit IgG</td><td>Life Technologies</td><td>A21428</td><td>Secondary antibody to label Gap43-RFP tracer.</td></tr><tr><td>9 Cavity spot plate</td><td>Corning</td><td>7220-85</td><td></td></tr><tr><td>Benzyl benzoate</td><td>Fisher</td><td>105862500</td><td>Optional - for clearing embryos</td></tr><tr><td>Benzyl alcohol</td><td>Fisher</td><td>A396-500</td><td>Optional - for clearing embryos</td></tr></tbody></table>

technique to target microinjection to the developing xenopus kidney

הכליה העוברית של Xenopus laevis (צפרדע), את כִּליַת רֵאשִׁית, מורכב נפרון יחיד, והוא יכול לשמש כמודל למחלת כליות. עוברי Xenopus הם גדולים, לפתח חיצונית, ניתן להשפיע בקלות על ידי microinjection או הליכים כירורגיים. בנוסף, מפות גורל הוקמו עבור עוברי Xenopus מוקדם. microinjection ממוקד לתוך blastomere הפרט כי בסופו של דבר יהיה להצמיח איבר או רקמה של עניין ניתן להשתמש כדי overexpress או להפיל ביטוי גנים באופן סלקטיבי בתוך האזור המוגבל הזאת, הפחתת השפעות משניות בשאר העובר המתפתח. בפרוטוקול זה, אנו מתארים כיצד לנצל מפות גורל Xenopus הוקמה כדי למקד את הכליה Xenopus פיתוח (להלן כִּליַת רֵאשִׁית), באמצעות microinjection לתוך blastomere ספציפיים של עוברים תאים 8 4 ו. הזרקה של קליעי נותבים שושלת מאפשרת אימות של המיקוד הספציפי של הזריקה.לאחר עוברים פתחו לשלב 38 - 40, כל הר immunostaining משמש כדי לחזות התפתחות pronephric, והתרומה ידי תאים ממוקדים אל כִּליַת רֵאשִׁית ניתן להעריך. באותה טכניקה ניתן להתאים למקד סוגי רקמות אחרות בנוסף כִּליַת רֵאשִׁית.

Microinjections של 4 ו-תאים 8 עוברי Xenopus עם mRNA MEM-RFP להראות רמות שונות של מיקוד אל כִּליַת רֵאשִׁית. איור 4 מראה הבמה 40 עוברים עם דפוסי ביטוי mRNA MEM-RFP הנכון. עובר הוזרקו ב blastomere הגחון השמאלי (איור 4 א), מיון עבור דפוס הביטוי ההולם של mRNA MEM-RFP. בנ...

Watch this Scientific Journal Video about Technique to Target Microinjection to the Developing Xenopus Kidney at JoVE.com

Technique to Target Microinjection to the Developing Xenopus Kidney

Here, we present a protocol to use fate maps and lineage tracers to target injections into individual blastomeres that give rise to the kidney of Xenopus laevis embryos.

טכניקה לכוון Microinjection אל פיתוח<em&gt; Xenopus</em&gt; כליה

The embryonic kidney of Xenopus&#160;laevis (frog), the pronephros, consists of a single nephron, and can be used as a model for kidney disease. Xenopus ...

technique-to-target-microinjection-to-the-developing-xenopus-kidney

Universidad San Sebastian

Research

JoVE Journal

Developmental Biology

Technique to Target Microinjection to the Developing Xenopus Kidney

11.2K Views.  University of Texas McGovern Medical School. Here, we present a protocol to use fate maps and lineage tracers to target injections into individual blastomeres that give rise to the kidney of Xenopus laevis embryos. 

Video: Technique to Target Microinjection to the Developing Xenopus Kidney

Using Confocal Analysis of Xenopus laevis to Investigate Modulators of Wnt and Shh Morphogen Gradients

This protocol describes a method to visualise ligands distributed across a field of cells. The ease of expressing exogenous proteins, together with the large size of their cells in early embryos, make Xenopus laevis a useful model for visualising GFP-tagged ligands. Synthetic mRNAs are efficiently translated after injection into early stage Xenopus embryos, and injections can be targeted to a single cell. When combined with a lineage tracer such as membrane tethered RFP, the injected cell (and its descendants) that are producing the overexpressed protein can easily be followed. This protocol describes a method for the production of fluorescently tagged Wnt and Shh ligands from injected mRNA. The methods involve the micro dissection of ectodermal explants (animal caps) and the analysis of ligand diffusion in multiple samples. By using confocal imaging, information about ligand secretion and diffusion over a field of cells can be obtained. Statistical analyses of confocal images provide quantitative data on the shape of ligand gradients. These methods may be useful to researchers who want to test the effects of factors that may regulate the shape of morphogen gradients.

Using Confocal Analysis of Xenopus laevis to Investigate Modulators of Wnt and Shh Morphogen Gradients

The manuscript here provides a simple set of methods for analysing the secretion and diffusion of fluorescently tagged ligands in Xenopus. This provides a context for testing the ability of other proteins to modify ligand distribution and allowing experiments that may give insight into mechanisms regulating morphogen gradients.

באמצעות ניתוח של Confocal<em&gt; Laevis Xenopus</em&gt; לחקירת מאפננים של עירובים מורפוגן Wnt וששש

This protocol describes a method to visualise ligands distributed across a field of cells. The ease of expressing exogenous proteins, together with the ...

Visualization and Quantitative Analysis of Embryonic Angiogenesis in Xenopus tropicalis

Blood vessels supply oxygen and nutrients throughout the body, and the formation of the vascular network is under tight developmental control. The efficient in vivo visualization of blood vessels and the reliable quantification of their complexity are key to understanding the biology and disease of the vascular network. Here, we provide a detailed method to visualize blood vessels with a commercially available fluorescent dye, human plasma acetylated low density lipoprotein DiI complex (DiI-AcLDL), and to quantify their complexity in Xenopus tropicalis. Blood vessels can be labeled by a simple injection of DiI-AcLDL into the beating heart of an embryo, and blood vessels in the entire embryo can be imaged in live or fixed embryos. Combined with gene perturbation by the targeted microinjection of nucleic acids and/or the bath application of pharmacological reagents, the roles of a gene or of a signaling pathway on vascular development can be investigated within one week without resorting to sophisticated genetically engineered animals. Because of the well-defined venous system of Xenopus and its stereotypic angiogenesis, the sprouting of pre-existing vessels, vessel complexity can be quantified efficiently after perturbation experiments. This relatively simple protocol should serve as an easily accessible tool in diverse fields of cardiovascular research.

Visualization and Quantitative Analysis of Embryonic Angiogenesis in Xenopus tropicalis

This protocol demonstrates a fluorescence-based method to visualize the vasculature and to quantify its complexity in Xenopus tropicalis. Blood vessels can be imaged minutes after the injection of a fluorescent dye into the beating heart of an embryo after genetic and/or pharmacological manipulations to study cardiovascular development in vivo.

ויזואליזציה וניתוח כמותי של אנגיוגנזה עובריים ב<em&gt; Xenopus טרופי</em

Blood vessels supply oxygen and nutrients throughout the body, and the formation of the vascular network is under tight developmental control. The ...

Microinjection of Xenopus Laevis Oocytes

Microinjection of Xenopus laevis oocytes followed by thin-sectioning electron microscopy (EM) is an excellent system for studying nucleocytoplasmic transport. Because of its large nucleus and high density of nuclear pore complexes (NPCs), nuclear transport can be easily visualized in the Xenopus oocyte. Much insight into the mechanisms of nuclear import and export has been gained through use of this system (reviewed by Pant&eacute;, 2006). In addition, we have used microinjection of Xenopus oocytes to dissect the nuclear import pathways of several viruses that replicate in the host nucleus. 
Here we demonstrate the cytoplasmic microinjection of Xenopus oocytes with a nuclear import substrate. We also show preparation of the injected oocytes for visualization by thin-sectioning EM, including dissection, dehydration, and embedding of the oocytes into an epoxy embedding resin. Finally, we provide representative results for oocytes that have been microinjected with the capsid of the baculovirus Autographa californica nucleopolyhedrovirus (AcMNPV) or the parvovirus Minute Virus of Mice (MVM), and discuss potential applications of the technique.

Here we demonstrate cytoplasmic microinjection of Xenopus laevis oocytes with a nuclear import substrate, as well as preparation of the injected oocytes for visualization by thin-sectioning electron microscopy.

Microinjection של ביציות Xenopus Laevis

Microinjection of Xenopus laevis oocytes followed by thin-sectioning electron microscopy (EM) is an excellent system for studying nucleocytoplasmic ...

Biology

Microinjection of mRNA and Morpholino Antisense Oligonucleotides in Zebrafish Embryos.

An essential tool for investigating the role of a gene during development is the ability to perform gene knockdown, overexpression, and misexpression studies. In zebrafish (Danio rerio), microinjection of RNA, DNA, proteins, antisense oligonucleotides and other small molecules into the developing embryo provides researchers a quick and robust assay for exploring gene function in vivo. In this video-article, we will demonstrate how to prepare and microinject in vitro synthesized EGFP mRNA and a translational-blocking morpholino oligo against pkd2, a gene associated with autosomal dominant polycystic kidney disease (ADPKD), into 1-cell stage zebrafish embryos. We will then analyze the success of the mRNA and morpholino microinjections by verifying GFP expression and phenotype analysis. Broad applications of this technique include generating transgenic animals and germ-line chimeras, cell-fate mapping and gene screening. Herein we describe a protocol for overexpression of EGFP and knockdown of pkd2 by mRNA and morpholino oligonucleotide injection.

Microinjection is a well-established and effective method for introducing foreign substances into fertilized zebrafish embryos. Here, we demonstrate a robust microinjection technique for performing mRNA overexpression, and morpholino oligonucleotide gene knockdown studies in zebrafish.

Microinjection של mRNA ו oligonucleotides Morpholino antisense עוברי דג הזברה.

An essential tool for investigating the role of a gene during development is the ability to perform gene knockdown, overexpression, and misexpression ...

Neural Explant Cultures from Xenopus laevis

The complex process of axon guidance is largely driven by the growth cone, which is the dynamic motile structure at the tip of the growing axon. During axon outgrowth, the growth cone must integrate multiple sources of guidance cue information to modulate its cytoskeleton in order to propel the growth cone forward and accurately navigate to find its specific targets1. How this integration occurs at the cytoskeletal level is still emerging, and examination of cytoskeletal protein and effector dynamics within the growth cone can allow the elucidation of these mechanisms. Xenopus laevis growth cones are large enough (10-30 microns in diameter) to perform high-resolution live imaging of cytoskeletal dynamics (e.g.2-4 ) and are easy to isolate and manipulate in a lab setting compared to other vertebrates. The frog is a classic model system for developmental neurobiology studies, and important early insights into growth cone microtubule dynamics were initially found using this system5-7 . In this method8, eggs are collected and fertilized in vitro, injected with RNA encoding fluorescently tagged cytoskeletal fusion proteins or other constructs to manipulate gene expression, and then allowed to develop to the neural tube stage. Neural tubes are isolated by dissection and then are cultured, and growth cones on outgrowing neurites are imaged. In this article, we describe how to perform this method, the goal of which is to culture Xenopus laevis growth cones for subsequent high-resolution image analysis. While we provide the example of +TIP fusion protein EB1-GFP, this method can be applied to any number of proteins to elucidate their behaviors within the growth cone.

Neural Explant Cultures from Xenopus laevis

Culturing neural explants from dissected Xenopus laevis embryos that express fluorescent fusion proteins allows for imaging of growth cone cytoskeletal dynamics.

תרבויות Explant עצביות מן<em&gt; Xenopus laevis</em

The complex process of axon guidance is largely driven by the growth cone, which is the dynamic motile structure at the tip of the growing axon. During ...

Neuroscience

Microinjection of DNA into Eyebuds in Xenopus laevis Embryos and Imaging of GFP Expressing Optic Axonal Arbors in Intact, Living Xenopus Tadpoles

The primary visual projection of tadpoles of the aquatic frog Xenopus laevis serves as an excellent model system for studying mechanisms that regulate the development of neuronal connectivity. During establishment of the retino-tectal projection, optic axons extend from the eye and navigate through distinct regions of the brain to reach their target tissue, the optic tectum. Once optic axons enter the tectum, they elaborate terminal arbors that function to increase the number of synaptic connections they can make with target interneurons in the tectum. Here, we describe a method to express DNA encoding green fluorescent protein (GFP), and gain- and loss-of-function gene constructs, in optic neurons (retinal ganglion cells) in Xenopus embryos. We explain how to microinject a combined DNA/lipofection reagent into eyebuds of one day old embryos such that exogenous genes are expressed in single or small numbers of optic neurons. By tagging genes with GFP or co-injecting with a GFP plasmid, terminal axonal arbors of individual optic neurons with altered molecular signaling can be imaged directly in brains of intact, living Xenopus tadpoles several days later, and their morphology can be quantified. This protocol allows for determination of cell-autonomous molecular mechanisms that underlie the development of optic axon arborization in vivo.

Microinjection of DNA into Eyebuds in Xenopus laevis Embryos and Imaging of GFP Expressing Optic Axonal Arbors in Intact, Living Xenopus Tadpoles

This protocol aims to demonstrate how to microinject a DNA/DOTAP mixture into eyebuds of one day old Xenopus laevis embryos, and how to image and reconstruct individual green fluorescent protein (GFP) expressing optic axonal arbors in tectal midbrains of intact, living Xenopus tadpoles.

הזרקת דנ א לתוך eyebuds ב xenopus זריזה העוברים והדמיה של gfp המבטא האופטי axonal הביע בשלמותו, חי xenopus tadpoles

The primary visual projection of tadpoles of the aquatic frog Xenopus laevis serves as an excellent model system for studying mechanisms that regulate the ...

Polarized Translocation of Fluorescent Proteins in Xenopus Ectoderm in Response to Wnt Signaling

Cell polarity is a fundamental property of eukaryotic cells that is dynamically regulated by both intrinsic and extrinsic factors during embryonic development 1, 2. One of the signaling pathways involved in this regulation is the Wnt pathway, which is used many times during embryogenesis and critical for human disease3, 4, 5. Multiple molecular components of this pathway coordinately regulate signaling in a spatially-restricted manner, but the underlying mechanisms are not fully understood. Xenopus embryonic epithelial cells is an excellent system to study subcellular localization of various signaling proteins. Fluorescent fusion proteins are expressed in Xenopus embryos by RNA microinjection, ectodermal explants are prepared and protein localization is evaluated by epifluorescence. In this experimental protocol we describe how subcellular localization of Diversin, a cytoplasmic protein that has been implicated in signaling and cell polarity determination6, 7 is visualized in Xenopus ectodermal cells to study Wnt signal transduction8. Coexpression of a Wnt ligand or a Frizzled receptor alters the distribution of Diversin fused with red fluorescent protein, RFP, and recruits it to the cell membrane in a polarized fashion 8, 9. This ex vivo protocol should be a useful addition to in vitro studies of cultured mammalian cells, in which spatial control of signaling differs from that of the intact tissue and is much more difficult to analyze.

Polarized Translocation of Fluorescent Proteins in Xenopus Ectoderm in Response to Wnt Signaling

Xenopus embryonic ectoderm has become an attractive model for studies of cell polarity. An assay is described, in which subcellular distribution of fluorescent proteins is assessed in ectoderm cells. This protocol will help address questions related to spatial control of signaling.

טרנסלוקציה מקוטב של חלבוני ניאון ב Xenopus האאקטודרם בתגובה איתות Wnt

Cell polarity is a fundamental property of eukaryotic cells that is dynamically regulated by both intrinsic and extrinsic factors during embryonic ...

Nephrotoxin Microinjection in Zebrafish to Model Acute Kidney Injury

The kidneys are susceptible to harm from exposure to chemicals they filter from the bloodstream. This can lead to organ injury associated with a rapid decline in renal function and development of the clinical syndrome known as acute kidney injury (AKI). Pharmacological agents used to treat medical circumstances ranging from bacterial infection to cancer, when administered individually or in combination with other drugs, can initiate AKI. Zebrafish are a useful animal model to study the chemical effects on renal function in vivo, as they form an embryonic kidney comprised of nephron functional units that are conserved with higher vertebrates, including humans. Further, zebrafish can be utilized to perform genetic and chemical screens, which provide opportunities to elucidate the cellular and molecular facets of AKI and develop therapeutic strategies such as the identification of nephroprotective molecules. Here, we demonstrate how microinjection into the zebrafish embryo can be utilized as a paradigm for nephrotoxin studies.

Renal injuries incurred from nephrotoxins, which include drugs ranging from antibiotics to chemotherapeutics, can result in complex disorders whose pathogenesis remains incompletely understood. This protocol demonstrates how zebrafish can be used for disease modeling of these conditions, which can be applied to the identification of renoprotective measures.

Nephrotoxin Microinjection דג הזברה למודל אי-ספיקת כליות חריפה

The kidneys are susceptible to harm from exposure to chemicals they filter from the bloodstream. This can lead to organ injury associated with a rapid ...

Xenopus Oocytes: Optimized Methods for Microinjection, Removal of Follicular Cell Layers, and Fast Solution Changes in Electrophysiological Experiments

The Xenopus oocyte as a heterologous expression system for proteins, was first described by Gurdon et al.1 and has been widely used since its discovery (References 2 - 3, and references therein). A characteristic that makes the oocyte attractive for foreign channel expression is the poor abundance of endogenous ion channels4. This expression system has proven useful for the characterization of many proteins, among them ligand-gated ion channels.
The expression of GABAA receptors in Xenopus oocytes and their functional characterization is described here, including the isolation of oocytes, microinjections with cRNA, the removal of follicular cell layers, and fast solution changes in electrophysiological experiments. The procedures were optimized in this laboratory5,6 and deviate from the ones routinely used7-9. Traditionally, denuded oocytes are prepared with a prolonged collagenase treatment of ovary lobes at RT, and these denuded oocytes are microinjected with mRNA. Using the optimized methods, diverse membrane proteins have been expressed and studied with this system, such as recombinant GABAA receptors10-12, human recombinant chloride channels13, Trypanosome potassium channels14, and a myo-inositol transporter15, 16.
The methods detailed here may be applied to the expression of any protein of choice in Xenopus oocytes, and the rapid solution change can be used to study other ligand-gated ion channels.

Xenopus Oocytes: Optimized Methods for Microinjection, Removal of Follicular Cell Layers, and Fast Solution Changes in Electrophysiological Experiments

Optimized procedures for the isolation of single follicles, cytoplasmic RNA microinjections, the removal of surrounding cell layers, and protein expression in Xenopus oocytes are described. In addition, a simple method for fast solution changes in electrophysiological experiments with ligand-gated ion channels is presented.

Xenopus ביציות: שיטות אופטימיזציה עבור Microinjection, הסרת שכבות ניידות זקיקים, ושינויי פתרון מהירים בניסויי אלקטרו

The Xenopus oocyte as a heterologous expression system for proteins, was first described by Gurdon et al.1 and has been widely used since its discovery ...

Hydrodynamic Renal Pelvis Injection for Non-viral Expression of Proteins in the Kidney

Hydrodynamic injection creates a local, high-pressure environment to transfect various tissues with plasmid DNA and other substances. Hydrodynamic tail vein injection, for example, is a well-established method by which the liver can be transfected. This manuscript describes an application of hydrodynamic principles by injection of the mouse kidney directly with plasmid DNA for kidney-specific gene expression. Mice are anesthetized and the kidney is exposed by a flank incision followed by a fast injection of a plasmid DNA-containing solution directly into the renal pelvis. The needle is kept in place for ten seconds and the incision site is sutured. The following day, live animal imaging, Western blot, or immunohistochemistry may be used to assay gene expression, or other assays suited to the transgene of choice are used for detection of the protein of interest. Published methods to prolong gene expression include transposon-mediated transgene integration and cyclophosphamide treatment to inhibit the immune response to the transgene.

This protocol describes a method to inject plasmid DNA into the mouse kidney via the renal pelvis to produce transgene expression specifically in the kidney.

הזרקת hydrodynamic אגן הכליה נגיפי ביטוי של חלבונים בתוך הכליה.

Hydrodynamic injection creates a local, high-pressure environment to transfect various tissues with plasmid DNA and other substances. Hydrodynamic tail ...

טכניקה לכוון Microinjection אל פיתוח

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