המחברים מודים בהכרת תודה על עבודתם של ליוליו ז'נג וזנגווי שו, שעזרו לחלוץ טכניקה זו במעבדת סוקאק, כמו גם חסן סד שעזר בניתוח. העבודה למחקר זה ממומנת על ידי מענק מ- NIH (R01 GM115111).

<ol>
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R., Blackstone, N., Jiang, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=RNAi+interference+by+dsRNA+injection+into+Drosophila+embryos.">RNAi interference by dsRNA injection into Drosophila embryos.</a> Journal of Visualized Experiments. (50), 2477 (2011).</li><li>Juarez, M. T., Patterson, R. 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לא הוכרזו ניגודי אינטרסים.

משמעותה של שיטה זו היא שהיא משתמשת בפרוטוקול מבוסס היטב של microinjection בעוברים Drosophila 21,22,23,24,25,26,27 כדי לאפשר מחקר חדש לגבי ASR וליווי הרכבת מוט actin. היתרון העיקרי ש?...

פרוטוקול זה מתאר כיצד להזריק G-actinאדום כדי לדמיין את ההרכבה של מוטות actin תוך גרעיני בעוברים לחוצים חום שעוברים תגובת מתח Actin בלתי ניתנת לערעור (ASR)1. פיתחנו פרוטוקול זה כדי לסייע במחקרים של ASR, אשר בעוברים מוביל מורפוגנזה משובשת וכדאיות מופחתת, ובסוגי תאים אנושיים בוגרים קשורה פתולוגיות כולל אי ספיקת כליות2, מיופתיות שרירים3, אלצהיימר ומחלת הנטינגטון4,5,6,7,8. זה ASR הוא המושרה על ידי לחצים תאיים רבים, כולל הלם חום9,10,11, מתח חמצוני4,6, סינתזת ATPמופחתת 12, ו האנטינטין חריג או אוליגומריזציה עמילואיד β4,5,6,7,9,13,14,15,16. סימן ההיכר של ASR הוא הרכבה של מוטות אקטין חריגים בציטופלסמה או בגרעין של תאים מושפעים, המונע על ידי היפראקטיביות הנגרמת על ידי מתח של חלבון אינטראקציה actin, Cofilin1,5,6,10. למרבה הצער, פערי ידע מרכזיים נשארים לגבי ASR. לדוגמה, הפונקציה של מוטות actin אינו ידוע. איננו מבינים מדוע מוטות נוצרים בציטופלסמה של סוגים מסוימים של תאים, אלא בגרעין של אחרים. כמו כן לא ברור אם ASR הוא מגן או לא מתאים עבור תאים או עוברים שעברו מתח. לבסוף, אנחנו עדיין לא יודעים את המנגנונים המפורטים שבבסיס היפראקטיביות Cofilin או הרכבה מוט actin. לפיכך, פרוטוקול זה מספק בדיקה מהירה ורב-תכליתית כדי לחקור את ASR על ידי הדמיה היווצרות מוט actin ודינמיקה במערכת ניסיונית ניתנת להפעלה מאוד של עובר זבוב הפירות החי.
הפרוטוקול כדי microinject G-actinאדום לתוך עוברים חיים Drosophila פותחה בתחילה כדי ללמוד את הדינמיקה של מבנים נורמליים cytoplasmic actin17 במהלך אירועי בניית רקמות. במחקרים אלה, מצאנו כיהזרקת אדום G-actin לא השפיעה לרעה על תהליכים התפתחותיים מוקדמים בעובר, כולל ציטוקינזיס או גסטריולציה17,18. לאחר מכן שינינו את הפרוטוקול, התאמת הטיפול בעוברוהזרקת אדום G-actin כדי לאפשר הדמיה של מוטות actin בחום עוברים ASR1. שיטות אחרות מלבדהזרקת אדום G-actin ניתן להשתמש כדי לדמיין actin בעוברים. שיטות אלה מסתמכות על ביטוי חלבונים פלואורסצנטיים (FPs) המתויגים לפעול או לתחומים של חלבונים מחייבים actin, כגון Utrophin-mCherry, Lifeact, F-tractin-GFP, ו Moesin-GFP (נבדק בשנת19). עם זאת, באמצעות בדיקות FP אלה דורש זהירות כי הם יכולים לייצב או לשבש כמה מבנים actin, לא באותה מידה תווית כל מבני actin20, ובמקרה של actin-GFP, הם מוגזמים מאוד – בעייתי לניתוח של הרכבת מוט אשר לא רק תלוי מתח אלא גם actin ריכוז תלוי1. לכן, G-actinאדום הוא החללית המועדפת על מחקרי מוט בעוברים לעוף, ואת הגודל הגדול של העובר מאפשר הזרקה קלה שלה.
זרימת העבודה של פרוטוקול זה דומה לטכניקות microinjection מבוססות אחרות ששימשו להזרקת חלבונים, חומצות גרעין, תרופות, אינדיקטורים פלואורסצנטיים לתוך עוברי Drosophila 21,22,23,24,25,26,27. עם זאת, בעקבות microinjection של אדום G-actin כאן, עוברים נחשפים ללחץ חום קל כדי לגרום ASR והרכבה מוט actin תוך-גרעיני. עבור מעבדות עם גישה זבובים אסדת הזרקה, שיטה זו צריכה להיות מיושמת בקלות להתאמה עבור קווי לימוד ספציפיים לגבי ASR, כולל אינדוקציה שלה על ידי לחצים שונים או אפנון ברקעים גנטיים שונים.

<table border="0" cellpadding="0" cellspacing="0" style="width:837px;" width="838">
	<tbody>
		<tr height="40">
			<td height="40" style="height:40px;width:223px;">Adenosine triphosphate (ATP)</td>
			<td style="width:195px;">Millipore-Sigma</td>
			<td style="width:121px;">A23835G</td>
			<td style="width:299px;">Component of G buffer</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">Apple juice, Mott&#39;s, 64 fl oz</td>
			<td style="width:195px;">Mott&#39;s</td>
			<td style="width:121px;">014800000344</td>
			<td>Component of apple juice plates</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">Bacto Agar</td>
			<td style="width:195px;">BD</td>
			<td style="width:121px;">214010</td>
			<td>Component of apple juice plates</td>
		</tr>
		<tr height="60">
			<td height="60" style="height:60px;width:223px;">Bleach, PureBright Germicidal, 6.0% sodium hypochlorite</td>
			<td style="width:195px;">KIK International</td>
			<td style="width:121px;">059647210020</td>
			<td>For dechorionating embryos</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">Calcium chloride</td>
			<td style="width:195px;">Millipore-Sigma</td>
			<td style="width:121px;">C1016500G</td>
			<td>Component of G buffer</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">Cell strainer, 70 &#956;m</td>
			<td style="width:195px;">Falcon</td>
			<td style="width:121px;">352350</td>
			<td>For collecting dechorionated embryos</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:223px;">Confocal microscope, LSM 880 34-channel with Airyscan</td>
			<td style="width:195px;">Zeiss</td>
			<td style="width:121px;">0000001994956</td>
			<td>For imaging intranuclear actin rods</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">Desiccant</td>
			<td style="width:195px;">Drierite</td>
			<td style="width:121px;">24001</td>
			<td>For desiccating embryos</td>
		</tr>
		<tr height="60">
			<td height="60" style="height:60px;width:223px;">Dissecting microscope, Stemi 508 Stereoscope with 8:1 zoom</td>
			<td style="width:195px;">Zeiss</td>
			<td style="width:121px;">4350649000000</td>
			<td>For arranging embryos on agar wedge</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">Dissecting needle, 5 in</td>
			<td style="width:195px;">Fisher Scientific</td>
			<td style="width:121px;">08965A</td>
			<td>For arranging embryos on agar wedge</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">Dithiothreitol (DTT)</td>
			<td style="width:195px;">Fisher Scientific</td>
			<td style="width:121px;">BP1725</td>
			<td>Component of G buffer</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:223px;">Double-sided Tape, Scotch Permanent, 0.5 in x 250 in</td>
			<td style="width:195px;">3M</td>
			<td>021200010323</td>
			<td>For making embryo glue</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">Embryo collection cage</td>
			<td style="width:195px;">Genessee Scientific</td>
			<td style="width:121px;">59100</td>
			<td>For housing adult flies and collecting embryos</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:223px;">Fine tip tweezers, Dumont Tweezer, Style 5</td>
			<td style="width:195px;">Electron Microscopy Sciences</td>
			<td style="width:121px;">72701D</td>
			<td>For arranging embryos on agar wedge</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:223px;">Glass capillaries, Borosillicate glass, thin 1 mm x 0.75 mm</td>
			<td style="width:195px;">World Precision Instruments, Inc.</td>
			<td style="width:121px;">TW1004</td>
			<td>For microneedles</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">Halocarbon oil 27</td>
			<td style="width:195px;">Millipore-Sigma</td>
			<td style="width:121px;">H8773100ML</td>
			<td>For hydration of embryos</td>
		</tr>
		<tr height="120">
			<td height="120" style="height:120px;width:223px;">Heated stage incubator</td>
			<td style="width:195px;">Zeiss</td>
			<td style="width:121px;">4118579020000, 4118609020000, 4118609010000</td>
			<td>For confocal imaging</td>
		</tr>
		<tr height="18">
			<td height="18" style="height:19px;width:223px;">Lab Tissue Wipers, KimWipes</td>
			<td style="width:195px;">Kimberly-Clark</td>
			<td style="width:121px;">34155</td>
			<td>Lab tissue wipers</td>
		</tr>
		<tr height="60">
			<td height="60" style="height:60px;width:223px;">Light microscope, Invertoskop 40C Inverted Phase contrast microscope, refurbished</td>
			<td style="width:195px;">Zeiss</td>
			<td style="width:121px;">Discontinued</td>
			<td>Injection microscope</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">Methyl-4-hydroxybenzoate</td>
			<td style="width:195px;">Millipore-Sigma</td>
			<td style="width:121px;">H36471KG</td>
			<td>Component of apple juice plates</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">Microinjector, FemtoJet4x</td>
			<td style="width:195px;">Eppendorf</td>
			<td>5253000025</td>
			<td>Microinjector</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:223px;">Micro loader tips, epT.I.P.S. 20 &#956;L</td>
			<td style="width:195px;">Eppendorf</td>
			<td style="width:121px;">5242956003</td>
			<td>For loading microneedles</td>
		</tr>
		<tr height="60">
			<td height="60" style="height:60px;width:223px;">Micromanipulator and injection stage with x,y,z dials for needle adjustment</td>
			<td style="width:195px;">Bernard Instruments, Inc (Houston, TX)</td>
			<td style="width:121px;">Custom</td>
			<td>For performing microinjections</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:223px;">Micropipette puller, Model P-97, Flaming/Brown</td>
			<td style="width:195px;">Sutter Instruments</td>
			<td style="width:121px;">P97</td>
			<td>For pulling capillary tubes to make microneedles</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:223px;">Microscope cover glass 24x50-1.5</td>
			<td style="width:195px;">Fisher Scientific</td>
			<td style="width:121px;">12544E</td>
			<td>For mounting embryos</td>
		</tr>
		<tr height="60">
			<td height="60" style="height:60px;width:223px;">Microscope slides, Lilac Colorfrost, Precleaned, 25 x 75 x 1mm</td>
			<td style="width:195px;">Fisher Scientific</td>
			<td style="width:121px;">22037081</td>
			<td>For mounting embryos for injection</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">n-Heptane</td>
			<td style="width:195px;">Fisher Scientific</td>
			<td style="width:121px;">H3601</td>
			<td>Component of embryo glue</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">Objective, 10x</td>
			<td style="width:195px;">Zeiss</td>
			<td style="width:121px;">Discontinued</td>
			<td>10x objective for injection microscope</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:223px;">Objective, C-Apochromat 40x/1,2 W Korr. FCS</td>
			<td style="width:195px;">Zeiss</td>
			<td style="width:121px;">4217679971711</td>
			<td>40x water objective for confocal</td>
		</tr>
		<tr height="41">
			<td height="41" style="height:41px;width:223px;">Objective, LD LCI Plan-Apochromat 25x/0.8 Imm Cor DIC M27 for oil, water, silicone oil or glycerine immersion (D=0-0.17mm) (WD=0.57mm at D=0.17mm)</td>
			<td style="width:195px;">Zeiss</td>
			<td style="width:121px;">4208529871000</td>
			<td>25x mixed immersion objective for confocal</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:223px;">Objective, Plan-Apocrhomat 63x/1.40 Oil DIC f/ELYRA</td>
			<td style="width:195px;">Zeiss</td>
			<td style="width:121px;">4207829900799</td>
			<td>63x oil objective for confocal</td>
		</tr>
		<tr height="60">
			<td height="60" style="height:60px;width:223px;">Paintbrush, Robert Simmons Expression E85 Pointed Round size 2</td>
			<td style="width:195px;">Daler-Rowney</td>
			<td style="width:121px;">038372016954</td>
			<td>For transferring embryos</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:223px;">Paper towels, Kleenex C-fold paper towels, white</td>
			<td style="width:195px;">Kimberly-Clark</td>
			<td style="width:121px;">884266344845</td>
			<td>For blotting cell strainer</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">Pasteur pipette, 5 3/4 in</td>
			<td style="width:195px;">Fisher Scientific</td>
			<td style="width:121px;">1367820A</td>
			<td>For covering embryos with oil</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">Petri dish, glass, 100 x 20 mm</td>
			<td style="width:195px;">Corning</td>
			<td style="width:121px;">3160102</td>
			<td>For humid incubation chamber</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">Petri dish, plastic, 60 x 15 mm</td>
			<td style="width:195px;">VWR</td>
			<td style="width:121px;">25384092</td>
			<td>For apple juice plates</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:223px;">Pipette, Eppendorf Reference 0.5-10 &#956;L</td>
			<td style="width:195px;">Eppendorf</td>
			<td style="width:121px;">2231000604</td>
			<td>For loading the microneedle</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">Pipette tip, xTIP4 250 &#956;L</td>
			<td style="width:195px;">Biotix</td>
			<td style="width:121px;">63300006</td>
			<td>For adding embryo glue to coverslip</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">Razor blade</td>
			<td style="width:195px;">VWR</td>
			<td style="width:121px;">55411050</td>
			<td>For cutting agar wedge, tape, pipette tips</td>
		</tr>
		<tr height="60">
			<td height="60" style="height:60px;width:223px;">Rhodamine-conjugated globular actin, human platelet (non-muscle; 4x10 &#956;g)</td>
			<td style="width:195px;">Cytoskeleton, Inc.</td>
			<td style="width:121px;">APHR-A</td>
			<td>G-actin^Red</td>
		</tr>
		<tr height="60">
			<td height="60" style="height:60px;width:223px;">Scintillation vial, 20 mL Glass borosillicate with polyethylene liner and urea caps</td>
			<td style="width:195px;">Fisher Scientific</td>
			<td style="width:121px;">033377</td>
			<td>For making embryo glue</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">Screw top jar, 16 oz</td>
			<td style="width:195px;">Nalgene</td>
			<td style="width:121px;">000194414195</td>
			<td>For desiccating embryos</td>
		</tr>
		<tr height="40">
			<td height="40" style="height:40px;width:223px;">Stage micrometer</td>
			<td style="width:195px;">Electron Microscopy Sciences</td>
			<td style="width:121px;">602104PG</td>
			<td>For calibrating volume of G-actin injection</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">Sucrose</td>
			<td style="width:195px;">Millipore-Sigma</td>
			<td style="width:121px;">840971KG</td>
			<td>Component of apple juice plates</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:223px;">Trizma base</td>
			<td style="width:195px;">Millipore-Sigma</td>
			<td style="width:121px;">T15031KG</td>
			<td>Component of G buffer</td>
		</tr>
		<tr height="60">
			<td height="60" style="height:60px;width:223px;">Yeast, Lesaffre Yeast Corporation Yeast, Red Star Active Dry, 32 oz</td>
			<td style="width:195px;">Lesaffre Yeast Corporation</td>
			<td style="width:121px;">117929157002</td>
			<td>Component of yeast paste</td>
		</tr>
	</tbody>
</table>

imaging intranuclear actin rods in live heat stressed drosophila embryos

מטרת פרוטוקול זה היא לדמיין מוטות אקטין תוך-גרעיניים המתכנסים בעוברים חיים של דרוזופילה מלנוגאסטר בעקבות עומס חום. מוטות אקטין הם סימן היכר של תגובת מתח Actin שמורה ובלתי ניתנת להכנעה (ASR) המלווה פתולוגיות אנושיות, כולל מחלה נוירודגנרטיבית. בעבר, הראינו כי ASR תורם כשלים morphogenesis וכדאיות מופחתת של פיתוח עוברים. פרוטוקול זה מאפשר את המשך המחקר של מנגנונים שבבסיס הרכבת מוט actin ו ASR במערכת מודל כי הוא מאוד נוח הדמיה, גנטיקה וביוכימיה. עוברים נאספים ומורכבים על כיסוי כדי להכין אותם להזרקה. אקטין כדורי מצומד רודמין (G-actinאדום)מדולל וטעון לתוך microneedle. זריקה אחת נעשית למרכזו של כל עובר. לאחר ההזרקה, העוברים הם דגירה בטמפרטורה גבוהה מוטות actin תוך גרעיניים הם דמיינו לאחר מכן על ידי מיקרוסקופיה confocal. התאוששות פלואורסצנטית לאחר ניסויים photobleaching (FRAP) ניתן לבצע על מוטות actin; ומבנים אחרים עשירים באקטין בציטופלסמה יכולים גם הם להדמיינו. אנו מוצאים כי G-actinאדום polymerizes כמו G-actin אנדוגני ואינו, בכוחות עצמו, להפריע להתפתחות העובר נורמלי. מגבלה אחת של פרוטוקול זה היא כי יש לנקוט טיפול במהלך ההזרקה, כדי למנוע פגיעה חמורה בעובר. עם זאת, עם תרגול, הזרקת G-actinאדום לתוך עוברים Drosophila היא דרך מהירה ואמינה לדמיין מוטות actin והוא יכול לשמש בקלות עם זבובים של כל גנוטיפ או עם כניסתה של לחצים הסלולר אחרים, כולל היפוקסיה ומתח חמצוני.

זרימת עבודה סכמטית של טיפול בעובר מתוארת באיור 1, ולוח זמנים לניסוי טיפוסי מוצג בטבלה 1. הערכה לתוצאה ניסיונית טובה היא שעל כל 10 עוברים שהוזרקו, לפחות מחצית מהעוברים שנצפו יהיו בשלב ההתפתחותי הנכון, לא ניזוקו, ויפגינו ASR חזק עם עומס חום ב 32 מעלות צלזיוס. ASR זה יתגלה ע?...

Watch this Scientific Journal Video about Imaging Intranuclear Actin Rods in Live Heat Stressed Drosophila Embryos at JoVE.com

Imaging Intranuclear Actin Rods in Live Heat Stressed Drosophila Embryos

המטרה של פרוטוקול זה היא להזריק רודמין מצומד אקטין כדורי לתוך עוברים Drosophila ואת התמונה הרכבה מוט actin תוך גרעיני בעקבות עומס חום.

הדמיה מוטות Actin תוך-גרעיניים בחום חי הדגישו עוברי דרוזופילה

The purpose of this protocol is to visualize intranuclear actin rods that assemble in live Drosophila melanogaster embryos following heat stress. Actin ...

imaging-intranuclear-actin-rods-live-heat-stressed-drosophila

Universidad San Sebastian

Research

JoVE Journal

Developmental Biology

Imaging Intranuclear Actin Rods in Live Heat Stressed Drosophila Embryos

3.4K Views.  Baylor College of Medicine. המטרה של פרוטוקול זה היא להזריק רודמין מצומד אקטין כדורי לתוך עוברים Drosophila ואת התמונה הרכבה מוט actin תוך גרעיני בעקבות עומס חום.

Video: Imaging Intranuclear Actin Rods in Live Heat Stressed Drosophila Embryos

Live-imaging of the Drosophila Pupal Eye

Inherent processes of Drosophila pupal development can shift and distort the eye epithelium in ways that make individual cell behavior difficult to track during live cell imaging. These processes include: retinal rotation, cell growth and organismal movement. Additionally, irregularities in the topology of the epithelium, including subtle bumps and folds often introduced as the pupa is prepared for imaging, make it challenging to acquire in-focus images of more than a few ommatidia in a single focal plane. The workflow outlined here remedies these issues, allowing easy analysis of cellular processes during Drosophila pupal eye development. Appropriately-staged pupae are arranged in an imaging rig that can be easily assembled in most laboratories. Ubiquitin-DE-Cadherin:GFP and GMR-GAL4&#8211;driven UAS-&#945;-catenin:GFP are used to visualize cell boundaries in the eye epithelium 1-3. After deconvolution is applied to fluorescent images captured at multiple focal planes, maximum projection images are generated for each time point and enhanced using image editing software. Alignment algorithms are used to quickly stabilize superfluous motion, making individual cell behavior easier to track.

Live-imaging of the Drosophila Pupal Eye

This protocol presents an efficient method for imaging the live Drosophila pupal eye neuroepithelium. This method compensates for tissue movement and uneven topology, enhances visualization of cell boundaries through the use of multiple GFP-tagged junction proteins, and uses an easily-assembled imaging rig.

Live-הדמיה של<em&gt; דרוזופילה</em&gt; גלמי עין

Inherent processes of Drosophila pupal development can shift and distort the eye epithelium in ways that make individual cell behavior difficult to track ...

Ploidy Manipulation of Zebrafish Embryos with Heat Shock 2 Treatment

Manipulation of ploidy allows for useful transformations, such as diploids to tetraploids, or haploids to diploids. In the zebrafish Danio rerio, specifically the generation of homozygous gynogenetic diploids is useful in genetic analysis because it allows the direct production of homozygotes from a single heterozygous mother. This article describes a modified protocol for ploidy duplication based on a heat pulse during the first cell cycle, Heat Shock 2 (HS2). Through inhibition of centriole duplication, this method results in a precise cell division stall during the second cell cycle. The precise one-cycle division stall, coupled to unaffected DNA duplication, results in whole genome duplication. Protocols associated with this method include egg and sperm collection, UV treatment of sperm, in vitro fertilization and heat pulse to cause a one-cell cycle division delay and ploidy duplication. A modified version of this protocol could be applied to induce ploidy changes in other animal species.

A modified protocol for ploidy manipulation uses a heat shock to induce a one-cycle stall in cytokinesis in the early embryo. This protocol is demonstrated in the zebrafish but may be applicable to other species.

מניפולציה ploidy של עוברי דג הזברה עם חום 2 הלם טיפול

Manipulation of ploidy allows for useful transformations, such as diploids to tetraploids, or haploids to diploids. In the zebrafish Danio rerio, ...

Biosensing Motor Neuron Membrane Potential in Live Zebrafish Embryos

The protocols described here are designed to allow researchers to study cell communication without altering the integrity of the environment in which the cells are located. Specifically, they have been developed to analyze the electrical activity of excitable cells, such as spinal neurons. In such a scenario, it is crucial to preserve the integrity of the spinal cell, but it is also important to preserve the anatomy and physiological shape of the systems involved. Indeed, the comprehension of the manner in which the nervous system-and other complex systems-works must be based on a systemic approach. For this reason, the live zebrafish embryo was chosen as a model system, and the spinal neuron membrane voltage changes were evaluated without interfering with the physiological conditions of the embryos. 
Here, an approach combining the employment of zebrafish embryos with a FRET-based biosensor is described. Zebrafish embryos are characterized by a very simplified nervous system and are particularly suited for imaging applications thanks to their transparency, allowing for the employment of fluorescence-based voltage indicators at the plasma membrane during zebrafish development. The synergy between these two components makes it possible to analyze the electrical activity of the cells in intact living organisms, without perturbing the physiological state. Finally, this non-invasive approach can co-exist with other analyses (e.g., spontaneous movement recordings, as shown here).

Protocols described here allow for the study of the electrical properties of excitable cells in the most non-invasive physiological conditions by employing zebrafish embryos in an in vivo system together with a fluorescence resonance energy transfer (FRET)-based genetically encoded voltage indicator (GEVI) selectively expressed in the cell type of interest.

Biosensing מוטורית נוירון פוטנציאל ממברנה עוברי דג הזברה חיים

The protocols described here are designed to allow researchers to study cell communication without altering the integrity of the environment in which the ...

Long-term Live Imaging of Drosophila Eye Disc

Live imaging provides the ability to continuously track dynamic cellular and developmental processes in real time. Drosophila larval imaginal discs have been used to study many biological processes, such as cell proliferation, differentiation, growth, migration, apoptosis, competition, cell-cell signaling, and compartmental boundary formation. However, methods for the long-term ex vivo culture and live imaging of the imaginal discs have not been satisfactory, despite many efforts. Recently, we developed a method for the long-term ex vivo culture and live imaging of imaginal discs for up to 18 h. In addition to using a high insulin concentration in the culture medium, a low-melting agarose was also used to embed the disc to prevent it from drifting during the imaging period. This report uses the eye-antennal discs as an example. Photoreceptor R3/4-specific m&#948;0.5-Ga4 expression was followed to demonstrate that photoreceptor differentiation and ommatidial rotation can be observed during a 10 h live imaging period. This is a detailed protocol describing this simple method.

Long-term Live Imaging of Drosophila Eye Disc

This protocol describes a detailed method for the long-term ex vivo culture and live imaging of a Drosophila imaginal disc. It demonstrates photoreceptor differentiation and ommatidial rotation within the 10 h period of live imaging of the eye disc. The protocol is simple and does not require expensive setup.

הדמיה לטווח ארוך בשידור חי של<em&gt; דרוזופילה</em&gt; דיסק העין

Live imaging provides the ability to continuously track dynamic cellular and developmental processes in real time. Drosophila larval imaginal discs have ...

In Vitro Ovule Cultivation for Live-cell Imaging of Zygote Polarization and Embryo Patterning in Arabidopsis thaliana

In most flowering plants, the zygote and embryo are hidden deep in the mother tissue, and thus it has long been a mystery of how they develop dynamically; for example, how the zygote polarizes to establish the body axis and how the embryo specifies various cell fates during organ formation. This manuscript describes an in vitro ovule culture method to perform live-cell imaging of developing zygotes and embryos of Arabidopsis thaliana. The optimized cultivation medium allows zygotes or early embryos to grow into fertile plants. By combining it with a poly(dimethylsiloxane) (PDMS) micropillar array device, the ovule is held in the liquid medium in the same position. This fixation is crucial to observe the same ovule under a microscope for several days from the zygotic division to the late embryo stage. The resulting live-cell imaging can be used to monitor the real-time dynamics of zygote polarization, such as nuclear migration and cytoskeleton rearrangement, and also the cell division timing and cell fate specification during embryo patterning. Furthermore, this ovule cultivation system can be combined with inhibitor treatments to analyze the effects of various factors on embryo development, and with optical manipulations such as laser disruption to examine the role of cell-cell communication.

In Vitro Ovule Cultivation for Live-cell Imaging of Zygote Polarization and Embryo Patterning in Arabidopsis thaliana

This manuscript describes an in vitro ovule cultivation method that enables live-cell imaging of Arabidopsis zygotes and embryos. This method is utilized to visualize the intracellular dynamics during zygote polarization and the cell fate specification in developing embryos.

במבחנה ביצית טיפוח עבור Live-תא הדמיה של הזיגוטה קיטוב והמתבנת העובר ב תודרנית לבנה

In most flowering plants, the zygote and embryo are hidden deep in the mother tissue, and thus it has long been a mystery of how they develop dynamically; ...

Live Imaging of Mouse Secondary Palate Fusion

The fusion of the secondary palatal shelves to form the intact secondary palate is a key process in mammalian development and its disruption can lead to cleft secondary palate, a common congenital anomaly in humans. Secondary palate fusion has been extensively studied leading to several proposed cellular mechanisms that may mediate this process. However, these studies have been mostly performed on fixed embryonic tissues at progressive timepoints during development or in fixed explant cultures analyzed at static timepoints. Static analysis is limited for the analysis of dynamic morphogenetic processes such a palate fusion and what types of dynamic cellular behaviors mediate palatal fusion is incompletely understood. Here we describe a protocol for live imaging of ex vivo secondary palate fusion in mouse embryos. To examine cellular behaviors of palate fusion, epithelial-specific Keratin14-cre was used to label palate epithelial cells in ROSA26-mTmGflox reporter embryos. To visualize filamentous actin, Lifeact-mRFPruby reporter mice were used. Live imaging of secondary palate fusion was performed by dissecting recently-adhered secondary palatal shelves of embryonic day (E) 14.5 stage embryos and culturing in agarose-containing media on a glass bottom dish to enable imaging with an inverted confocal microscope. Using this method, we have detected a variety of novel cellular behaviors during secondary palate fusion. An appreciation of how distinct cell behaviors are coordinated in space and time greatly contributes to our understanding of this dynamic morphogenetic process. This protocol can be applied to mutant mouse lines, or cultures treated with pharmacological inhibitors to further advance understanding of how secondary palate fusion is controlled.

Here, we present a protocol for live imaging of mouse secondary palate fusion using confocal microscopy. This protocol can be used in combination with a variety of fluorescent reporter mouse lines, and with pathway inhibitors for mechanistic insight. This protocol can be adapted for live imaging in other developmental systems.

הדמיה חיה של עכבר משניים פיוז &#39;ן

The fusion of the secondary palatal shelves to form the intact secondary palate is a key process in mammalian development and its disruption can lead to ...

Live Imaging and Analysis of Muscle Contractions in Drosophila Embryo

Coordinated muscle contractions are a form of rhythmic behavior seen early during development in Drosophila embryos. Neuronal sensory feedback circuits are required to control this behavior. Failure to produce the rhythmic pattern of contractions can be indicative of neurological abnormalities. We previously found that defects in protein O-mannosylation, a posttranslational protein modification, affect the axon morphology of sensory neurons and result in abnormal coordinated muscle contractions in embryos. Here, we present a relatively simple method for recording and analyzing the pattern of peristaltic muscle contractions by live imaging of late stage embryos up to the point of hatching, which we used to characterize the muscle contraction phenotype of protein O-mannosyltransferase mutants. Data obtained from these recordings can be used to analyze muscle contraction waves, including frequency, direction of propagation and relative amplitude of muscle contractions at different body segments. We have also examined body posture and taken advantage of a fluorescent marker expressed specifically in muscles to accurately determine the position of the embryo midline. A similar approach can also be utilized to study various other behaviors during development, such as embryo rolling and hatching.

Live Imaging and Analysis of Muscle Contractions in Drosophila Embryo

Here, we present a method to record embryonic muscle contractions in Drosophila embryos in a non-invasive and detail-oriented manner.

הדמיה חיה וניתוח של התכווצויות שרירים בתוך העובר דרוזופילה

Coordinated muscle contractions are a form of rhythmic behavior seen early during development in Drosophila embryos. Neuronal sensory feedback circuits ...

Dissection and Live-Imaging of the Late Embryonic Drosophila Gonad

The Drosophila melanogaster male embryonic gonad is an advantageous model to study various aspects of developmental biology including, but not limited to, germ cell development, piRNA biology, and niche formation. Here, we present a dissection technique to live-image the gonad ex vivo during a period when in vivo live-imaging is highly ineffective. This protocol outlines how to transfer embryos to an imaging dish, choose appropriately-staged male embryos, and dissect the gonad from its surrounding tissue while still maintaining its structural integrity. Following dissection, gonads can be imaged using a confocal microscope to visualize dynamic cellular processes. The dissection procedure requires precise timing and dexterity, but we provide insight on how to prevent common mistakes and how to overcome these challenges. To our knowledge this is the first dissection protocol for the Drosophila embryonic gonad, and will permit live-imaging during an otherwise inaccessible window of time. This technique can be combined with pharmacological or cell-type specific transgenic manipulations to study any dynamic processes occurring within or between the&#160;cells in their natural gonadal environment.

Dissection and Live-Imaging of the Late Embryonic Drosophila Gonad

Here, we provide a dissection protocol required to live-image the late embryonic Drosophila male gonad. This protocol will permit observation of dynamic cellular processes under normal conditions or after transgenic or pharmacological manipulation.

דיסקציה והדמיה חיה של דרוזופילה גונד העוברית המאוחרת

The Drosophila melanogaster male embryonic gonad is an advantageous model to study various aspects of developmental biology including, but not limited to, ...

Applications of Immobilization of Drosophila Tissues with Fibrin Clots for Live Imaging

Drosophila is an important model system to study a vast range of biological questions. Various organs and tissues from different developmental stages of the fly such as imaginal discs, the larval brain or egg chambers of adult females or the adult intestine can be extracted and kept in culture for imaging with time-lapse microscopy, providing valuable insights into cell and developmental biology. Here, we describe in detail our current protocol for the dissection of Drosophila larval brains, and then present our current approach for immobilizing and orienting larval brains and other tissues on a glass coverslip using Fibrin clots. This immobilization method only requires the addition of Fibrinogen and Thrombin to the culture medium. It is suitable for high-resolution time lapse imaging on inverted microscopes of multiple samples in the same culture dish, minimizes the lateral drifting frequently caused by movements of the microscope stage in multi-point visiting microscopy and allows for the addition and removal of reagents during the course of imaging. We also present custom-made macros that we routinely use to correct for drifting and to extract and process specific quantitative information from time-lapse analysis.

Applications of Immobilization of Drosophila Tissues with Fibrin Clots for Live Imaging

This protocol describes applications of sample immobilization using Fibrin clots, limiting drifting, and allowing the addition and washout of reagents during live imaging. Samples are transferred to a drop of Fibrinogen containing culture medium on the surface of a coverslip, after which polymerization is induced by adding thrombin.

יישומים של קיבוע של רקמות Drosophila עם קרישי פיברין להדמיה חיה

Drosophila is an important model system to study a vast range of biological questions. Various organs and tissues from different developmental stages of ...

עיכוב אופטוגנטי של התכווצות אקטומיוזין בתיווך Rho1 בדרוזופילה

Optogenetic Inhibition of Rho1-Mediated Actomyosin Contractility Coupled with Measurement of Epithelial Tension in Drosophila Embryos

Contractile forces generated by actin and non-muscle myosin II ("actomyosin contractility") are critical for morphological changes of cells and tissues at multiple length scales, such as cell division, cell migration, epithelial folding, and branching morphogenesis. An in-depth understanding of the role of actomyosin contractility in morphogenesis requires approaches that allow the rapid inactivation of actomyosin, which is difficult to achieve using conventional genetic or pharmacological approaches. The presented protocol demonstrates the use of a CRY2-CIBN based optogenetic dimerization system, Opto-Rho1DN, to inhibit actomyosin contractility in Drosophila embryos with precise temporal and spatial controls. In this system, CRY2 is fused to the dominant negative form of Rho1 (Rho1DN), whereas CIBN is anchored to the plasma membrane. Blue light-mediated dimerization of CRY2 and CIBN results in rapid translocation of Rho1DN from the cytoplasm to the plasma membrane, where it inactivates actomyosin by inhibiting endogenous Rho1. In addition, this article presents a detailed protocol for coupling Opto-Rho1DN-mediated inactivation of actomyosin with laser ablation to investigate the role of actomyosin in generating epithelial tension during Drosophila ventral furrow formation. This protocol can be applied to many other morphological processes that involve actomyosin contractility in Drosophila embryos with minimal modifications. Overall, this optogenetic tool is a powerful approach to dissect the function of actomyosin contractility in controlling tissue mechanics during dynamic tissue remodeling.

מחבר זרקור: עיכוב אופטוגנטי של התכווצות אקטומיוזין בתיווך Rho1 יחד עם מדידת מתח אפיתל בעוברי דרוזופילה  

Actomyosin contractility plays an important role in cell and tissue morphogenesis. However, it is challenging to manipulate actomyosin contractility in vivo acutely. This protocol describes an optogenetic system that rapidly inhibits Rho1-mediated actomyosin contractility in Drosophila embryos, revealing the immediate loss of epithelial tension after the inactivation of actomyosin in vivo.

עיכוב אופטוגנטי של התכווצות אקטומיוזין בתיווך Rho1 יחד עם מדידת מתח אפיתל בעוברי דרוזופילה

Contractile forces generated by actin and non-muscle myosin II ("actomyosin contractility") are critical for morphological changes of cells and tissues at ...