עבודה זו נתמכה על ידי המכונים הלאומיים לבריאות מענקים 2R01 GM53132 ו P50 GM071558.

<ol>
	<li>Cheng, H., Lederer, M. R., Lederer, W. J., Cannell, M. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Calcium+sparks+and+[Ca2+]i+waves+in+cardiac+myocytes.">Calcium sparks and [Ca2+]i waves in cardiac myocytes.</a> Am. J. Physiol. Cell. Physiol. 270, 148-159 (1996).</li><li>Cheng, H., Lederer, W. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Calcium+Sparks.">Calcium Sparks.</a> Physiol. Rev. 88, 1491-1545 (2008).</li><li>Rebecchi, M. J., Pentyala, S. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structure,+function,+and+control+of+phosphoinositide-specific+phospholipase.">Structure, function, and control of phosphoinositide-specific phospholipase.</a> C. Physiol.Rev. 80, 1291-1335 (2000).</li><li>Suh, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multiple+roles+of+phosphoinositide-specific+phospholipase+C+isozymes.">Multiple roles of phosphoinositide-specific phospholipase C isozymes.</a> BMB reports. 41, 415-434 (2008).</li><li>Schlegel, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Crowded+little+caves:+structure+and+function+of+caveolae.">Crowded little caves: structure and function of caveolae.</a> Cell. Signal. 10, 457-463 (1998).</li><li>Anderson, R. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+caveolae+membrane+system.">The caveolae membrane system.</a> Annu. Rev. Biochem. 67, 199-225 (1998).</li><li>Sengupta, P., Philip, F., Scarlata, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Caveolin-1+alters+Ca2++signal+duration+through+specific+interaction+with+the+G{alpha}q+family+of+G+proteins.">Caveolin-1 alters Ca2+ signal duration through specific interaction with the G{alpha}q family of G proteins.</a> J. Cell. Sci. 121, 1363-1372 (2008).</li><li>Guo, Y., Golebiewska, U., Scarlata, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modulation+of+Ca2++Activity+in+Cardiomyocytes+through+Caveolae-G[alpha]q+Interactions.">Modulation of Ca2+ Activity in Cardiomyocytes through Caveolae-G[alpha]q Interactions.</a> Biophysical. Journal. 100, 1599-1607 (1016).</li><li>Rybin, V. O., Xu, X., Lisanti, M. P., Steinberg, S. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differential+targeting+of+beta+-adrenergic+receptor+subtypes+and+adenylyl+cyclase+to+cardiomyocyte+caveolae.+A+mechanism+to+functionally+regulate+the+cAMP+signaling+pathway.">Differential targeting of beta -adrenergic receptor subtypes and adenylyl cyclase to cardiomyocyte caveolae. A mechanism to functionally regulate the cAMP signaling pathway.</a> J. Biol. Chem. 275, 41447-41457 (2000).</li><li>Tovey, S. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Calcium+puffs+are+generic+InsP3-activated+elementary+calcium+signals+and+are+downregulated+by+prolonged+hormonal+stimulation+to+inhibit+cellular+calcium+responses.">Calcium puffs are generic InsP3-activated elementary calcium signals and are downregulated by prolonged hormonal stimulation to inhibit cellular calcium responses.</a> J. Cell. Sci. 114, 3979-3989 (2001).</li><li>Lohn, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ignition+of+Calcium+Sparks+in+Arterial+and+Cardiac+Muscle+Through+Caveolae.">Ignition of Calcium Sparks in Arterial and Cardiac Muscle Through Caveolae.</a> Circ. Res. 87, 1034-1039 (2000).</li></ol>

אין ניגודי אינטרסים הכריז.

פיתחנו שיטה להציג לבודד אותות סידן המהירה cardiomyocytes חיים. בעוד תנאי הניסוי של מדידות אלה בעבר ליישם מערכות תאים אחרים, כמו גם 10 cardiomyocytes 11, השימוש היסטוגרמות וניתוח סל מאפשרת נתונים רבים Ca 2 + אירועים להירכש. אירועי מהר ניתן לבודד בקלות מאלו ומודלים איטי...

<table border="1" style=";text-align:right;direction:rtl"><tbody><tr><td> שם מגיב </td><td> חברה </td><td> מספר קטלוגי </td><td> תגובות </td></tr><tr><td> DMEM </td><td> Invitrogen </td><td> ABCD1234 </td><td></td></tr></tbody></table>

measuring fast calcium fluxes in cardiomyocytes

Cardiomyocytes יש מספר רב של Ca 2 + והנתיבים משתנה משך שפועלים יחד כדי לייעל 1,2 לתפקד. שינויים Ca 2 + לפעילות בתגובה סוכני תאי מווסת בעיקר על ידי מסלול phospholipase q Cβ-Gα מקומי על קרום הפלזמה אשר מגורה על ידי הסוכנים כגון אצטילכולין 3,4. לאחרונה מצאנו כי חלבון הנקרא פלזמה קרום תחומים caveolae 5,6 יכול ללכוד מופעל Gα q 7. מלכודת זו יש אפקט של ייצוב מצב של הפעלת Gα q וכתוצאה מכך Ca 2 + ממושכת אותות cardiomyocytes סוגי תאים אחרים 8. חשפנו תוצאה זו מפתיעה על ידי מדידת התגובות סידן דינמי בקנה מידה מהיר cardiomyocytes חיים. בקצרה, תאים נטענים עם אינדיקטור ניאון Ca + 2. במחקרים, השתמשנו Ca 2 + ירוק (Invitrogen, בג) אשר מציג עלייה בעוצמת פליטת הקרינה על הכריכה של יוני סידן. עוצמת הקרינה היא רשמה אז לשימוש במצב קו סריקה של קרן לייזר סריקת מיקרוסקופ confocal. שיטה זו מאפשרת רכישה מהירה של מהלך הזמן של עוצמת הקרינה בפיקסלים לאורך קו נבחר, לייצר כמה מאות עקבות הזמן בסולם זמן המיקרו. עקבות אלה מהר מאוד מועברים לתוך Excel ולאחר מכן לתוך Sigmaplot לניתוח, והם לעומת עקבות שהתקבלו רעש אלקטרוני, לצבוע בחינם, פקדים אחרים. כדי לנתח Ca 2 + התגובות של שיעורי השטף שונות, ביצענו ניתוח ההיסטוגרמה כי זרקת לפח בעוצמות פיקסל עם הזמן. Binning מאפשר לנו קבוצה מעל 500 עקבות של סריקות לחזות את התוצאות שנאספו במרחב ובזמן על מגרש אחד. לפיכך, להאט את גלי Ca 2 + שקשה להבחין כאשר הסריקות הם כיסו בשל מיקום שיא רעש שונים, ניתן לראות בקלותהיסטוגרמות זרקת לפח. והנתיבים מהר מאוד בסולם זמן המדידה להראות הפצה הצר של עוצמות של פחי זמן קצר מאוד כבר בעוד Ca 2 + גלי להראות נתונים זרקת לפח עם הפצה רחבה מעל פחי זמן רב יותר. אלו הפצות זמן שונים מאפשרים לנו לנתח את התזמון של Ca 2 + והנתיבים בתאים, ולקבוע את השפעתם על אירועים הסלולר השונות.

Watch this Scientific Journal Video about Measuring Fast Calcium Fluxes in Cardiomyocytes at JoVE.com

Measuring Fast Calcium Fluxes in Cardiomyocytes

אנו מציגים שיטה לבודד מהירה (מיקרו) האירועים סידן והנתיבים איטי יותר בתאים חיים באמצעות לייזר מיקרוסקופיית confocal. שיטה מודד תנודות בעוצמת הקרינה של אינדיקטורים סידן על ידי קו סריקות הקלטה מאות פיקסלים מספר בתא. ניתוח היסטוגרמה מאפשר לנו לבודד את הכף זמן של והנתיבים סידן שונים.

מדידת Fluxes סידן מהיר ב cardiomyocytes

Cardiomyocytes have multiple Ca2+ fluxes of varying duration that work together to optimize function 1,2. Changes in Ca2+ activity in response to ...

measuring-fast-calcium-fluxes-in-cardiomyocytes

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Biology

15.1K Views.  Queensborough Community College. אנו מציגים שיטה לבודד מהירה (מיקרו) האירועים סידן והנתיבים איטי יותר בתאים חיים באמצעות לייזר מיקרוסקופיית confocal. שיטה מודד תנודות בעוצמת הקרינה של אינדיקטורים סידן על ידי קו סריקות הקלטה מאות פיקסלים מספר בתא. ניתוח היסטוגרמה מאפשר לנו לבודד את הכף זמן של והנתי?...

Video: Measuring Fast Calcium Fluxes in Cardiomyocytes

Measuring Near Plasma Membrane and Global Intracellular Calcium Dynamics in Astrocytes

The brain contains glial cells.  Astrocytes, a type of glial cell, have long been known to provide a passive supportive role to neurons. However, increasing evidence suggests that astrocytes may also actively participate in brain function through functional interactions with neurons.  However, many fundamental aspects of astrocyte biology remain controversial, unclear and/or experimentally unexplored. One important issue is the dynamics of intracellular calcium transients in astrocytes. This is relevant because calcium is well established as an important second messenger and because it has been proposed that astrocyte calcium elevations can trigger the release of transmitters from astrocytes. However, there has not been any detailed or satisfying description of near plasma membrane calcium signaling in astrocytes. Total internal reflection fluorescence (TIRF) microscopy is a powerful tool to analyze physiologically relevant signaling events within about 100 nm of the plasma membrane of live cells. Here, we use TIRF microscopy and describe how to monitor near plasma membrane and global intracellular calcium dynamics almost simultaneously. The further refinement and systematic application of this approach has the potential to inform about the precise details of astrocyte calcium signaling. A detailed understanding of astrocyte calcium dynamics may provide a basis to understand if, how, when and why astrocytes and neurons undergo calcium-dependent functional interactions.

We describe how to measure near membrane and global intracellular calcium dynamics in cultured astrocytes using total internal reflection and epifluorescence microscopy.

מדידת הקרוב ממברנה פלזמה ו Global Dynamics סידן תאיים בתוך האסטרוציטים

The brain contains glial cells.  Astrocytes, a type of glial cell, have long been known to provide a passive supportive role to neurons. However, ...

Efficient Derivation of Human Cardiac Precursors and Cardiomyocytes from Pluripotent Human Embryonic Stem Cells with Small Molecule Induction

To date, the lack of a suitable human cardiac cell source has been the major setback in regenerating the human myocardium, either by cell-based transplantation or by cardiac tissue engineering1-3. Cardiomyocytes become terminally-differentiated soon after birth and lose their ability to proliferate. There is no evidence that stem/progenitor cells derived from other sources, such as the bone marrow or the cord blood, are able to give rise to the contractile heart muscle cells following transplantation into the heart1-3. The need to regenerate or repair the damaged heart muscle has not been met by adult stem cell therapy, either endogenous or via cell delivery1-3. The genetically stable human embryonic stem cells (hESCs) have unlimited expansion ability and unrestricted plasticity, proffering a pluripotent reservoir for in vitro derivation of large supplies of human somatic cells that are restricted to the lineage in need of repair and regeneration4,5. Due to the prevalence of cardiovascular disease worldwide and acute shortage of donor organs, there is intense interest in developing hESC-based therapies as an alternative approach. However, how to channel the wide differentiation potential of pluripotent hESCs efficiently and predictably to a desired phenotype has been a major challenge for both developmental study and clinical translation. Conventional approaches rely on multi-lineage inclination of pluripotent cells through spontaneous germ layer differentiation, resulting in inefficient and uncontrollable lineage-commitment that is often followed by phenotypic heterogeneity and instability, hence, a high risk of tumorigenicity6-8 (see a schematic in Fig. 1A). In addition, undefined foreign/animal biological supplements and/or feeders that have typically been used for the isolation, expansion, and differentiation of hESCs may make direct use of such cell-specialized grafts in patients problematic9-11. To overcome these obstacles, we have resolved the elements of a defined culture system necessary and sufficient for sustaining the epiblast pluripotence of hESCs, serving as a platform for de novo derivation of clinically-suitable hESCs and effectively directing such hESCs uniformly towards clinically-relevant lineages by small molecules12 (see a schematic in Fig. 1B). After screening a variety of small molecules and growth factors, we found that such defined conditions rendered nicotinamide (NAM) sufficient to induce the specification of cardiomesoderm direct from pluripotent hESCs that further progressed to cardioblasts that generated human beating cardiomyocytes with high efficiency (Fig. 2). We defined conditions for induction of cardioblasts direct from pluripotent hESCs without an intervening multi-lineage embryoid body stage, enabling well-controlled efficient derivation of a large supply of human cardiac cells across the spectrum of developmental stages for cell-based therapeutics.

We have established a protocol for induction of cardioblasts direct from pluripotent human embryonic stem cells maintained under defined conditions with small molecules, which enables derivation of a large supply of human cardiac progenitors and functional cardiomyocytes for cardiovascular repair.

גזירת יעיל של מבשרי לב cardiomyocytes האדם מן האדם תאים pluripotent גזע עובריים עם אינדוקציה מולקולה קטנה

To date, the lack of a suitable human cardiac cell source has been the major setback in regenerating the human myocardium, either by cell-based ...

Isolation and Kv Channel Recordings in Murine Atrial and Ventricular Cardiomyocytes

KCNE genes encode for a small family of Kv channel ancillary subunits that form heteromeric complexes with Kv channel alpha subunits to modify their functional properties. Mutations in KCNE genes have been found in patients with cardiac arrhythmias such as the long QT syndrome and/or atrial fibrillation. However, the precise molecular pathophysiology that leads to these diseases remains elusive. In previous studies the electrophysiological properties of the disease causing mutations in these genes have mostly been studied in heterologous expression systems and we cannot be sure if the reported effects can directly be translated into native cardiomyocytes. In our laboratory we therefore use a different approach. We directly study the effects of KCNE gene deletion in isolated cardiomyocytes from knockout mice by cellular electrophysiology - a unique technique that we describe in this issue of the Journal of Visualized Experiments. The hearts from genetically engineered KCNE mice are rapidly excised and mounted onto a Langendorff apparatus by aortic cannulation. Free Ca2+ in the myocardium is bound by EGTA, and dissociation of cardiac myocytes is then achieved by retrograde perfusion of the coronary arteries with a specialized low Ca2+ buffer containing collagenase. Atria, free right ventricular wall and the left ventricle can then be separated by microsurgical techniques. Calcium is then slowly added back to isolated cardiomyocytes in a multiple step comprising washing procedure. Atrial and ventricular cardiomyocytes of healthy appearance with no spontaneous contractions are then immediately subjected to electrophysiological analyses by patch clamp technique or other biochemical analyses within the first 6 hours following isolation.

Kv channel dysfunction is associated with cardiac arrhythmias. In order to study the molecular mechanisms that lead to such arrhythmias we utilize a systematic protocol for isolation of atrial and ventricular cardiomyocytes from Kv channel ancillary subunit knockout mice. Isolated cardiomyocytes can then immediately be used for cellular electrophysiological studies, biochemical or immunofluorescence (IF) assays.

בידוד והקלטות בערוץ KV בcardiomyocytes פרוזדורים וחדרית Murine

KCNE genes encode for a small family of Kv channel ancillary subunits that form heteromeric complexes with Kv channel alpha subunits to modify their ...

Isolation and Culture of Neonatal Mouse Cardiomyocytes

Cultured neonatal cardiomyocytes have long been used to study myofibrillogenesis and myofibrillar functions. Cultured cardiomyocytes allow for easy investigation and manipulation of biochemical pathways, and their effect on the biomechanical properties of spontaneously beating cardiomyocytes.	
The following 2-day protocol describes the isolation and culture of neonatal mouse cardiomyocytes. We show how to easily dissect hearts from neonates, dissociate the cardiac tissue and enrich cardiomyocytes from the cardiac cell-population. We discuss the usage of different enzyme mixes for cell-dissociation, and their effects on cell-viability. The isolated cardiomyocytes can be subsequently used for a variety of morphological, electrophysiological, biochemical, cell-biological or biomechanical assays. We optimized the protocol for robustness and reproducibility, by using only commercially available solutions and enzyme mixes that show little lot-to-lot variability. We also address common problems associated with the isolation and culture of cardiomyocytes, and offer a variety of options for the optimization of isolation and culture conditions.

Primary mouse cardiomyocyte cultures are one of the pivotal tools for the investigation of myofibrillar organization and function. The following protocol describes the isolation and culture of primary cardiomyocytes from neonatal mouse hearts. The resulting cardiomyocyte cultures may be subsequently used for a variety of biomechanical, biochemical and cell-biological assays.

בידוד והתרבות של שריר לב עכבר בילוד

Cultured neonatal cardiomyocytes have long been used to study  myofibrillogenesis and myofibrillar functions. Cultured cardiomyocytes allow  for easy ...

Measuring Glutathione-induced Feeding Response in Hydra

Hydra is among the most primitive organisms possessing a nervous system and chemosensation for detecting reduced glutathione (GSH) for capturing the prey. The movement of prey organisms causes mechanosensory discharge of the stinging cells called nematocysts from hydra, which are inserted into the prey. The feeding response in hydra, which includes curling of the tentacles to bring the prey towards the mouth, opening of the mouth and consequent engulfing of the prey, is triggered by GSH present in the fluid released from the injured prey. To be able to identify the molecular mechanism of the feeding response in hydra which is unknown to date, it is necessary to establish an assay to measure the feeding response. Here, we describe a simple method for the quantitation of the feeding response in which the distance between the apical end of the tentacle and mouth of hydra is measured and the ratio of such distance before and after the addition of GSH is determined. The ratio, called the relative tentacle spread, was found to give a measure of the feeding response. This assay was validated using a starvation model in which starved hydra show an enhanced feeding response in comparison with daily fed hydra.

Here we describe a simple assay for the quantification of the feeding response in hydra induced by the reduced form of glutathione. This assay relies on measuring the distance between the apical end of the tentacle and mouth of hydra.

מדידת תגובת האכלה מושרה גלוטתיון בהידרה

Hydra is among the most primitive organisms possessing a nervous system and chemosensation for detecting reduced glutathione (GSH) for capturing the prey. ...

Voltage and Calcium Dual Channel Optical Mapping of Cultured HL-1 Atrial Myocyte Monolayer

Optical mapping has proven to be a valuable technique to detect cardiac electrical activity on both intact ex vivo hearts and in cultured myocyte monolayers. HL-1 cells have been widely used as a 2-Dimensional cellular model for studying diverse aspects of cardiac physiology. However, it has been a great challenge to optically map calcium (Ca) transients and action potentials simultaneously from the same field of view in a cultured HL-1 atrial cell monolayer. This is because special handling and care is required to prepare healthy cells that can be electrically captured and optically mapped. Therefore, we have developed an optimal working protocol for dual channel optical mapping. In this manuscript, we have described in detail how to perform the dual channel optical mapping experiment. This protocol is a useful tool to enhance the understanding of action potential propagation and Ca kinetics in arrhythmia development.

This article describes the technique used to perform dual channel optical mapping in cultured HL-1 atrial cell monolayers. This unique protocol allows the simultaneous visualization of both calcium (Ca) and voltage (Vm) activity in the same area for the detailed detection and analysis of electrophysiological properties of culture monolayers.

מתח וסידן ערוץ כפול אופטי מיפוי של תרבית HL-1 פרוזדורים Myocyte חד שכבתי

Optical mapping has proven to be a valuable technique to detect cardiac electrical activity on both intact ex vivo hearts and in cultured myocyte ...

Isolation, Culture and Transduction of Adult Mouse Cardiomyocytes

Cultured cardiomyocytes can be used to study cardiomyocyte biology using techniques that are complementary to in vivo systems. For example, the purity and accessibility of in vitro culture enables fine control over biochemical analyses, live imaging, and electrophysiology. Long-term culture of cardiomyocytes offers access to additional experimental approaches that cannot be completed in short term cultures. For example, the in vitro investigation of dedifferentiation, cell cycle re-entry, and cell division has thus far largely been restricted to rat cardiomyocytes, which appear to be more robust in long-term culture. However, the availability of a rich toolset of transgenic mouse lines and well-developed disease models make mouse systems attractive for cardiac research. Although several reports exist of adult mouse cardiomyocyte isolation, few studies demonstrate their long-term culture. Presented here, is a step-by-step method for the isolation and long-term culture of adult mouse cardiomyocytes. First, retrograde Langendorff perfusion is used to efficiently digest the heart with proteases, followed by gravity sedimentation purification. After a period of dedifferentiation following isolation, the cells gradually attach to the culture and can be cultured for weeks. Adenovirus cell lysate is used to efficiently transduce the isolated cardiomyocytes. These methods provide a simple, yet powerful model system to study cardiac biology.

This protocol describes a step-by-step method for the reproducible isolation and long-term culture of adult mouse cardiomyocytes with high yield, purity, and viability.

בידוד, תרבות התמרה של cardiomyocytes עכבר למבוגרים

Cultured cardiomyocytes can be used to study cardiomyocyte biology using techniques that are complementary to in vivo systems. For example, the purity and ...

Measuring RAN Peptide Toxicity in C. elegans

C. elegans is commonly used to model age-related neurodegenerative diseases caused by repeat expansion mutations, such as Amyotrophic Lateral Sclerosis (ALS) and Huntington&#8217;s disease. Recently, repeat expansion-containing RNA was shown to be the substrate for a novel type of protein translation called repeat-associated non-AUG-dependent (RAN) translation. Unlike canonical translation, RAN translation does not require a start codon and only occurs when repeats exceed a threshold length. Because there is no start codon to determine the reading frame, RAN translation occurs in all reading frames from both sense and antisense RNA templates that contain a repeat expansion sequence. Therefore, RAN translation expands the number of possible disease-associated toxic peptides from one to six. Thus far, RAN translation has been documented in eight different repeat expansion-based neurodegenerative and neuromuscular diseases. In each case, deciphering which RAN products are toxic, as well as their mechanisms of toxicity, is a critical step towards understanding how these peptides contribute to disease pathophysiology. In this paper, we present strategies to measure the toxicity of RAN peptides in the model system C. elegans. First, we describe procedures for measuring RAN peptide toxicity on the growth and motility of developing C. elegans. Second, we detail an assay for measuring postdevelopmental, age-dependent effects of RAN peptides on motility. Finally, we describe a neurotoxicity assay for evaluating the effects of RAN peptides on neuron morphology. These assays provide a broad assessment of RAN peptide toxicity and may be useful for performing large-scale genetic or small molecule screens to identify disease mechanisms or therapies.

Measuring RAN Peptide Toxicity in C. elegans

Repeat-associated non-ATG-dependent translational products are emerging pathogenic features of several repeat expansion-based diseases. The goal of the protocol described is to evaluate toxicity caused by these peptides using behavioral and cellular assays in the model system C. elegans.

מדידת רעילות ב -C. אלגיה

C. elegans is commonly used to model age-related neurodegenerative diseases caused by repeat expansion mutations, such as Amyotrophic Lateral Sclerosis ...

Forward Genetic Screen Using Transgenic Calcium Reporter Aequorin to Identify Novel Targets in Calcium Signaling

Forward genetic screens have been important tools in the unbiased identification of genetic components involved in several biological pathways. The basis of the screen is to generate a mutant population that can be screened with a phenotype of interest. EMS (ethyl methane sulfonate) is a commonly used alkylating agent for inducing random mutation in a classical forward genetic screen to identify multiple genes involved in any given process. Cytosolic calcium (Ca2+) elevation is a key early signaling pathway that is activated upon stress perception. However the identity of receptors, channels, pumps and transporters of Ca2+ is still elusive in many study systems. Aequorin is a cellular calcium reporter protein isolated from Aequorea victoria and stably expressed in Arabidopsis. Exploiting this, we designed a forward genetic screen in which we EMS-mutagenized the aequorin transgenic. The seeds from the mutant plants were collected (M1) and screening for the phenotype of interest was carried out in the segregating (M2) population. Using a 96-well high-throughput Ca2+ measurement protocol, several novel mutants can be identified that have a varying calcium response and are measured in real time. The mutants with the phenotype of interest are rescued and propagated till a homozygous mutant plant population is obtained. This protocol provides a method for forward genetic screens in Ca2+ reporter background and identify novel Ca2+ regulated targets.

A forward genetic screen based on Ca2+ elevation as a read-out leads to identification of genetic components involved in calcium dependent signaling pathways in plants.

המסך הגנטי הקדמי באמצעות כתבת סידן טרנסגניים Aequorin כדי לזהות יעדים הרומן איתות סידן

Forward genetic screens have been important tools in the unbiased identification of genetic components involved in several biological pathways. The basis ...

Light Sheet Microscopy of Fast Cardiac Dynamics in Zebrafish Embryos

Embryonic cardiac research has greatly benefited from advances in fast in vivo light sheet fluorescence microscopy (LSFM). Combined with the rapid external development, tractable genetics, and translucency of the zebrafish, Danio rerio, LSFM has delivered insights into cardiac form and function at high spatial and temporal resolution without significant phototoxicity or photobleaching. Imaging of beating hearts challenges existing sample preparation and microscopy techniques. One needs to maintain a healthy sample in a constricted field of view and acquire ultrafast images to resolve the heartbeat. Here we describe optimized tools and solutions to study the zebrafish heart in vivo. We demonstrate the applications of bright transgenic lines for labeling the cardiac constituents and present novel gentle embedding and immobilization techniques that avoid developmental defects and changes in heart rate. We also propose a data acquisition and analysis pipeline adapted to cardiac imaging. The entire workflow presented here focuses on zebrafish embryonic heart imaging but can also be applied to various other samples and experiments.

We describe optimized tools to study the zebrafish heart in vivo with light sheet fluorescence microscopy. Specifically, we suggest bright cardiac transgenic lines and present new gentle embedding and immobilization techniques that avoid developmental and heart defects. A possible data acquisition and analysis pipeline adapted to cardiac imaging is also provided.