Gli autori desiderano ringraziare Irene Choi per illustrare le teste di embrioni in Fig. 1 e gli altri membri del laboratorio per l&#39;aiuto e la discussione. Questo lavoro è sostenuto da NIH sovvenzione DE012728 (TW)

1. Preparare dispasi II <ol><li> Preparare fresco Hepes-buffered saline (HBS) (50 mM Hepes / KOH pH 7,4, 150 mM NaCl). Aggiungere 2 ml di 0,5 M Hepes / KOH pH 7,4 e 1,2 ml 2.5 M NaCl in 16,8 ml ultrapura H 2 O. </li><li> Rendere 10 mg / ml dispasi II. Pesare 0,2 g dispasi II (Roche, Cat # 4942078001) e sciogliere in 20 ml di HBS. Preparare 1,0 ml aliquote nelle singole provette Eppendorf e conservare a -20 ° C per la conservazione a lungo termine. </li><li> Diluire 10 mg / ml dispasi II 1:10 in PBS prima dell&#39;uso. Mettere il diluito dispasi II su ghiaccio. </li></ol> 2. Dissect CD-1 E10.5 embrioni da Donne in stato di gravidanza Tutti gli esperimenti sugli animali sono stati eseguiti secondo protocolli approvati dalla University of Colorado Denver (UCD) Cura degli animali e del Comitato d&#39;uso. Topi CD-1 (ICR) sono stati ottenuti da Harlan Laboratories (Indianapolis, IN). <ol><li> Pulire la zona dissezione e gli strumenti con il 70% di etanolo. </li><li> Eutanasia incinta CD-1 femmina con approveD protocolli. </li><li> Spruzzare l&#39;addome con il 70% di etanolo quindi aprire l&#39;addome. Usare un set di pinze per tirare l&#39;utero e un altro per strappare il mesometrium dall&#39;utero. Rimuovere l&#39;utero dal corpo. Ripetere l&#39;operazione per corno uterino sull&#39;altro lato del ventre. </li><li> Sciacquare brevemente l&#39;utero con ghiaccio freddo PBS in un 10 cm piastra di Petri per lavare il sangue. </li><li> Trasferire l&#39;utero in un nuovo piatto di Petri con ghiaccio PBS freddo. Separati in un unico embrione-frammenti tagliando tra i siti di impianto. </li><li> Trasferire un solo embrione in ghiaccio-freddo PBS allo stereomicroscopio. Utilizzare una pinza sottile per strappare la parete muscolare dell&#39;utero a partire da uno dei siti di taglio per esporre l&#39;embrione con il sacco vitellino. Staccare il sacco vitellino e amnios. Trasferimento a un embrione sezionato 6 cm Petri con PBS su ghiaccio. Procedere fino a quando tutti gli embrioni sono stati raccolti in questo modo. </li></ol> 3. Dispasi II Trattamento <ol><li> Lavare tutti gli embrioni con PBS in un 6 cm piastra di Petri. SostituirePBS diluito con 10 ml dispasi II in PBS. Coprire la piastra di Petri e incubare a 37 ° C per 25 min - un batterica incubatore o camera calda dovrebbe essere sufficiente - non abbiamo usato un CO 2 di coltura tissutale incubatore per questo passo. </li><li> Prendere la piastra di Petri e osservare l&#39;embrione allo stereomicroscopio. L&#39;ectoderma dovrebbe si sono allentati, caratterizzata da un evidente divario tra questo strato di tessuto e il mesenchima sottostante. Se no, incubare per altri 5 minuti a 37 ° C. Poi mettere la piastra di Petri su ghiaccio. </li></ol> 4. Staccare le protuberanze intatte per il viso <ol><li> Utilizzare una pipetta di vetro monouso (VWR, Cat # 14672-380) trasferire una dispasi II trattato embrione in ghiacciata PBS in un 6 cm piastra di Petri allo stereomicroscopio. </li><li> Utilizzare un paio di pinze per tenere l&#39;embrione. Utilizzare un altro paio di pinze sottili attentamente per tagliare i confini delle protuberanze facciali attaccati alla testa (figura 1 mostra i confinile protuberanze del viso). Inizia da un lato della MNP, poi il MxP, e l&#39;ultima FNP. Fate lo stesso per l&#39;altro lato di sezionare le protuberanze facciali fuori intatta (Figura 2A). </li></ol> 5. Separata Ectoderma viso da Mesenchima <ol><li> Osservare le protuberanze del viso sotto uno stereomicroscopio con 3x distanza di lavoro. Utilizzare una pipetta Pasteur di vetro lunghe di pipettare delicatamente le protuberanze del viso su e giù per 5 volte. Dopo questo, l&#39;ectoderma è facile da staccare. </li><li> Utilizzare un paio di pinze per tenere le protuberanze del viso. Utilizzare l&#39;altra coppia di pinze per staccare l&#39;ectoderma molto lentamente. Figura 2B mostra i fogli separati di ectoderma facciale. </li><li> Utilizzare una nuova pipetta Pasteur di vetro lunghe per trasferire l&#39;ectoderma del viso in un 1,5 ml Eppendorf tubo con PBS su ghiaccio. Trasferire il mesenchima ad un altro 1,5 ml Eppendorf tubo con PBS su ghiaccio. </li><li> Utilizzate il nuovo ghiacciata PBS per ogni dissezione. Raccogliere campioni. </li><li> Lavare tegli campioni con PBS. Centrifugare a 4 ° C, 500 xg per 3 min. </li><li> Aspirare il PBS con lunghi vetro pipette Pasteur. Se i campioni devono essere utilizzati per il saggio ChIP, passare al punto 6.1. Per l&#39;estrazione di RNA, passare al punto 6.2. Per l&#39;estrazione di proteine, passare al punto 6.3. </li></ol> 6. I campioni di processo per ulteriori sperimentazioni <ol><li> I campioni per analisi ChIP <ol><li> Aggiungere 1 ml di PBS con 1% di formaldeide di reticolazione. Omogeneizzare i campioni. </li><li> Incubare a temperatura ambiente per 10 min con rotazione. </li><li> Aggiungere 110 ml di 1,25 M Glycine ad ogni provetta per placare la formaldeide che non ha reagito. </li><li> Miscelare ed incubare a temperatura ambiente per 5 min. </li><li> Centrifugare a 500 xg a 4 ° C per 3 min. Rimuovere il surnatante. </li><li> Aggiungere 1 ml di PBS per lavare i tessuti. </li><li> Centrifugare a 500 xg a 4 ° C per 3 min. </li><li> Rimuovere PBS e ripetere PBS lavare una volta. </li><li> Rimuovere il surnatante, Snap congelare i tessuti in azoto liquido. Conservare la samples a -80 ° C per la successiva messa in comune e l&#39;elaborazione. </li></ol></li><li> I campioni per l&#39;estrazione di RNA <ol><li> Posizionare il viso ectoderma e mesenchima in provette contenenti RNAlater (Ambion). </li><li> Incubare i campioni in soluzione RNAlater notte a 4 ° C per consentire una buona penetrazione del tessuto. </li><li> Conservare a -20 ° C per la successiva messa in comune e l&#39;elaborazione. </li></ol></li><li> I campioni per l&#39;estrazione delle proteine </li></ol> Aggiungere tampone di lisi al campione per la successiva lavorazione. Oppure scattare congelare i tessuti in azoto liquido. Conservare i campioni a -80 ° C per la successiva messa in comune e l&#39;elaborazione. Note <ol><li> Tempo di vincoli. Pianificare il 4-6 ore dall&#39;inizio della dissezione fino all&#39;inizio della sezione 6. </li><li> Quando esperti, ci vogliono 10-15 minuti per ~ embrione di eseguire sezioni 4 e 5 (dissezione rilievo e la separazione ectoderma). </li><li> Se i campioni di RNA isolamento, ogni solution deve essere trattata con dietilpirocarbonato prima. Pulire anche la pinza e l&#39;area di lavoro con RNase Away. </li><li> Mantenere i campioni nel ghiaccio sempre salvo per il trattamento dispasi II e dissezioni. Passare alla nuova ghiacciata PBS per ogni dissezione per assicurarsi che il PBS utilizzato per la dissezione è freddo. </li><li> Pinze Sharp sono fondamentali per ottenere dissezione precisa. Pulire le pinze completamente per evitare qualsiasi contaminazione. </li><li> Per la raccolta di campioni da diverse protuberanze, sezionare ogni rilievo separatamente, dopo il trattamento dispasi II. Poi separare l&#39;ectoderma e mesenchima. </li><li> Dopo il trattamento con dispasi II, l&#39;ectoderma facciale è facile da staccare. Prestare particolare attenzione alla contaminazione da ectoderma altri. Eliminare tutti i tessuti potenzialmente contaminati. </li><li> Una volta avviato, non si fermano fino a quando i campioni di raggiungere il punto appropriato nella sezione 6. Fine separazione tra ectoderma e mesenchima facciale per tutti gli embrioni nel più breve tempo possibile. </li><li> L&#39;indirizzo eattività di nzyme dispasi II potrebbe essere diversa tra i lotti e dei marchi. E &#39;necessario regolare il tempo di trattamento per diverse marche e lotti di dispasi II. </li></ol>

<ol>
	<li>Wilkie, A. O., Morriss-Kay, G. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Genetics+of+craniofacial+development+and+malformation.">Genetics of craniofacial development and malformation.</a> Nat. Rev. Genet. 2, 458-468 (2001).</li><li>Gritli-Linde, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chapter+2+-+The+Etiopathogenesis+of+cleft+lip+and+cleft+palate:+usefulness+and+caveats+of+mouse+models.">Chapter 2 - The Etiopathogenesis of cleft lip and cleft palate: usefulness and caveats of mouse models.</a> Current Topics in Developmental Biology. 84, 37-138 (2008).</li><li>Schutte, B. C., Murray, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+many+faces+and+factors+of+orofacial+clefts.">The many faces and factors of orofacial clefts.</a> Human Molecular Genetics. 8, 1-7 (1999).</li><li>Chai, Y., Maxson, R. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recent+advances+in+craniofacial+morphogenesis.">Recent advances in craniofacial morphogenesis.</a> Dev. Dyn. 235, 2353-2375 (2006).</li><li>Jiang, R., Bush, J. O., Lidral, A. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+the+upper+lip:+Morphogenetic+and+molecular+mechanisms.">Development of the upper lip: Morphogenetic and molecular mechanisms.</a> Dev. Dyn. 235, 1152-1166 (2006).</li><li>Reid, B. S., Yang, H., Melvin, V. S., Taketo, M. M., Williams, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ectodermal+WNT/&#946;-catenin+signaling+shapes+the+mouse+face.">Ectodermal WNT/&#946;-catenin signaling shapes the mouse face.</a> Developmental Biology. 349, 261-269 (2011).</li><li>Feng, W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Spatial+and+temporal+analysis+of+gene+expression+during+growth+and+fusion+of+the+mouse+facial+prominences.">Spatial and temporal analysis of gene expression during growth and fusion of the mouse facial prominences.</a> PLoS ONE. 4, e8066 (2009).</li><li>Chia, R., Achilli, F., Festing, M. F., Fisher, E. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+origins+and+uses+of+mouse+outbred+stocks.">The origins and uses of mouse outbred stocks.</a> Nat. Genet. 37 (11), 1181-1186 (2005).</li><li>Nagai, T., Aruga, J., Takada, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+expression+of+the+mouse+Zic1,+Zic2,+and+Zic3+gene+suggests+an+essential+role+for+Zic+genes+in+body+pattern+formation.">The expression of the mouse Zic1, Zic2, and Zic3 gene suggests an essential role for Zic genes in body pattern formation.</a> Developmental Biology. 182, 299-313 (1997).</li><li>Britsch, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+transcription+factor+Sox10+is+a+key+regulator+of+peripheral+glial+development.">The transcription factor Sox10 is a key regulator of peripheral glial development.</a> Genes Dev. 15 (1), 66-78 (2001).</li></ol>

Gli autori non hanno interessi in gioco o altri conflitti connessi con il contenuto di questo articolo.

Questo protocollo fornisce un metodo semplice per separare ectoderma embrionale del mouse e mesenchima facciale sulla base di una prima fase di trattamento dispasi II. In studi precedenti, abbiamo svolto dissezione delle protuberanze del viso prima del trattamento dispasi II, ma abbiamo sempre trovato che il mesenchima diventa &quot;appiccicoso&quot; e più difficile da manipolare. Il nostro nuovo protocollo evita questo problema. Combinazione dispasi II trattamento con dolce forza fisica pipettando su e giù rende sepa...

<table>
 <td>Name of Reagent/Material</td>
 <td>Company</td>
 <td>Catalog Number</td>
 <td>Comments</td>
 </tr>
 <td>Dispase II (neutral protease, grade II)</td>
 <td>Roche</td>
 <td>4942078001</td>
 <td>Make 10 mg/ml Dispase II stock solution in HBS. Aliquot and store at -20 &deg;C . </td>
 </tr>
 <td>RNAlater</td>
 <td>Ambion</td>
 <td>AM7021</td>
 <td>&nbsp;</td>
 </tr>
</table>

separation of mouse embryonic facial ectoderm and mesenchyme

Schisi oro-facciali sono i difetti più frequenti cranio-facciali, che colpiscono 1,5 nel 1000 1,2 neonati in tutto il mondo. Palatoschisi orofacciale è causata da abnorme 3 Sviluppo del viso. In mouse e dell&#39;essere umano, la crescita iniziale ed il modello del volto si basa su diversi piccoli boccioli di tessuto, le sporgenze del viso 4,5. Il volto è derivato da sei coppie di protuberanze principali: i processi frontali nasali (FNP), protuberanze mascellari (MXP) e protuberanze mandibolari (MdP). Tali prominenze consistono rigonfiamenti di mesenchima che sono incassati in un epitelio sovrastante. Gli studi condotti su specie diverse hanno dimostrato che la segnalazione crosstalk tra ectoderma e mesenchima del viso è fondamentale per plasmare il volto 6. Tuttavia, i dettagli meccanicistici riguardanti i geni coinvolti in questi relè di segnalazione sono carenti. Un modo per ottenere una comprensione globale di espressione genica, il fattore di trascrizione vincolante e marchi associati alla cromatina sviectoderma ping viso e mesenchima è quello di isolare e caratterizzare i compartimenti separati. Qui vi presentiamo un metodo per separare ectoderma del viso e del mesenchima al giorno embrionale (E) 10.5, una fase critica dello sviluppo nella formazione del mouse facciale che precede la fusione delle protuberanze. Il nostro metodo è adattato da un approccio che abbiamo utilizzato in precedenza per sezionare protuberanze facciali 7. In questo studio abbiamo utilizzato inbred C57BL / 6 topi come questo ceppo è diventato uno standard per la genetica, la genomica e la morfologia del viso 8. Qui, tuttavia, sia per le quantità più limitata di tessuto disponibili, abbiamo utilizzato la outbred CD-1 ceppo che è conveniente per l&#39;acquisto, più robusto per l&#39;allevamento, e tende a produrre più embrioni (12-18) per cucciolata di qualsiasi inbred topo strain 8. Dopo aver isolato embrione, neutro proteasi dispasi II è stato usato per trattare l&#39;embrione intero. Poi, le protuberanze facciali sono stati sezionareed out, e l&#39;ectoderma facciale è stato separato dal mesenchima. Questo metodo mantiene sia l&#39;ectoderma e mesenchima viso intatto. I campioni cosi ottenuti possono essere utilizzati per le tecniche di rilevamento tra proteine, immunoprecipitazione della cromatina (ChIP) assay, studi di microarray, e RNA-seq.

Dopo il trattamento dispasi II, l&#39;ectoderma dell&#39;embrione tende ad essere sciolto. Le protuberanze del viso dovrebbe essere intatto dopo la dissezione (Figura 2A). L&#39;ectoderma isolato viso è chiara e priva di tessuto mesenchima (Figura 2B). Per determinare l&#39;efficacia del protocollo e per rilevare la contaminazione incrociata abbiamo saggiato per proencefalo espresso ZIC3 9, ectodermica specifica CDH1 5 e mesenchimali specifica SOX10 10 ...

Watch this Scientific Journal Video about Separation of Mouse Embryonic Facial Ectoderm and Mesenchyme at JoVE.com

Separation of Mouse Embryonic Facial Ectoderm and Mesenchyme

Un protocollo per la separazione di ectoderma dell&#39;embrione del viso e del mesenchima è descritto. Usiamo dispasi II per il trattamento di embrioni interi in primo luogo, analizzare interi protuberanze del viso, e poi separare il viso ectoderma e mesenchima.

Separazione dei Ectoderma embrionali di topo viso e Mesenchima

 Orofacial clefts are the most frequent  craniofacial defects, which affect 1.5 in 1,000 newborns worldwide1,2. Orofacial clefting is caused by abnormal ...

separation-of-mouse-embryonic-facial-ectoderm-and-mesenchyme

Research

JoVE Journal

Biology

10.8K Views.  University of Colorado Denver Anschutz Medical Campus. Un protocollo per la separazione di ectoderma dell'embrione del viso e del mesenchima è descritto. Usiamo dispasi II per il trattamento di embrioni interi in primo luogo, analizzare interi protuberanze del viso, e poi separare il viso ectoderma e mesenchima.

Video: Separation of Mouse Embryonic Facial Ectoderm and Mesenchyme

Electrophoretic Separation of Proteins

Electrophoresis is used to separate complex mixtures of proteins (e.g., from cells, subcellular fractions, column fractions, or immunoprecipitates), to investigate subunit compositions, and to verify homogeneity of protein samples. It can also serve to purify proteins for use in further applications. In polyacrylamide gel electrophoresis, proteins migrate in response to an electrical field through pores in a polyacrylamide gel matrix; pore size decreases with increasing acrylamide concentration. The combination of pore size and protein charge, size, and shape determines the migration rate of the protein. In this unit, the standard Laemmli method is described for discontinuous gel electrophoresis under denaturing conditions, i.e., in the presence of sodium dodecyl sulfate (SDS). 

In this video, we demonstrate a method for electrophoretic separation of proteins using poly-acrylimide gel electrophoresis (PAGE).

Separazione elettroforetica delle proteine

Electrophoresis is used to separate complex mixtures of proteins (e.g., from cells, subcellular fractions, column fractions, or immunoprecipitates), to ...

Ricerca

Biologia

Isolation and Derivation of Mouse Embryonic Germinal Cells

The ability of embryonic germinal cells (EG) to differentiate into primordial germinal cells (PGCs) and later into gametes during early developmental stages is a perfect model to address our hypothesis about cancer and infertility. This protocol shows how to isolate primordial germinal cells from developing gonads in 10.5-11.5 days post coitum (dpc) mouse embryos.  Developing gonadal ridges from mouse embryos (C57BL6J) were dissociated by mechanical disruption with collagenase, then plated in a mouse embryo fibroblast feeder layer (MEF-CF1) that was previously mitotically inactivated with mitomycin C in the presence of knockout media and supplemented with Leukemia Inhibitor Factor (LIF), basic Fibroblast Growth Factor (bFGF), and Stem Cell Factor (SCF).  Using these optimized methods for PCG identification, isolation, and establishment of culture conditions permits long term cultures of EG cells for more than 40 days.  The embryonic germinal cell lines showed embryonic phenotype and expression of common used markers of the pluripotent state.  Isolation and derivation of germinal cells in culture provide a tool to understand their development in vitro and offer the opportunity to monitor cumulative damage at genetic and epigenetic levels after exposure to oxidative stress.

The ability of embryonic germinal cells to differentiate into primordial germinal cells during early development stages is a perfect model to address our hypothesis about cancer and infertility. This protocol shows how to isolate primordial germinal cells from developing gonads in 10.5-11.5 days post coitum mouse embryos.

L&#39;isolamento e la derivazione di cellule embrionali del mouse Germinal

The ability of embryonic germinal cells (EG) to differentiate into primordial germinal cells (PGCs) and later into gametes during early developmental ...

In vivo Imaging and Therapeutic Treatments in an Orthotopic Mouse Model of Ovarian Cancer

Human cancer and response to therapy is better represented in orthotopic animal models. This paper describes the development of an orthotopic mouse model of ovarian cancer, treatment of cancer via oral delivery of drugs, and monitoring of tumor cell behavior in response to drug treatment in real time using in vivo imaging system. In this orthotopic model, ovarian tumor cells expressing luciferase are applied topically by injecting them directly into the mouse bursa where each ovary is enclosed. Upon injection of D-luciferin, a substrate of firefly luciferase, luciferase-expressing cells generate bioluminescence signals. This signal is detected by the in vivo imaging system and allows for a non-invasive means of monitoring tumor growth, distribution, and regression in individual animals. Drug administration via oral gavage allows for a maximum dosing volume of 10 mL/kg body weight to be delivered directly to the stomach and closely resembles delivery of drugs in clinical treatments. Therefore, techniques described here, development of an orthotopic mouse model of ovarian cancer, oral delivery of drugs, and in vivo imaging, are useful for better understanding of human ovarian cancer and treatment and will improve targeting this disease.

In vivo Imaging and Therapeutic Treatments in an Orthotopic Mouse Model of Ovarian Cancer

Orthotopic animal models of ovarian cancer replicate better human disease and therefore enhance our understanding of cancer progression and tumor response to therapy. A mouse model receives an intrabursal injection of luciferase-expressing ovarian tumor cells. Treatment is administered via oral gavage. Tumor growth is monitored by in vivo imaging system.

Imaging in vivo e trattamenti terapeutici in un modello di mouse ortotopico di cancro ovarico

Human cancer and response to therapy is better represented in orthotopic animal models.  This paper describes the development of an orthotopic mouse model ...

Adenovirus-mediated Genetic Removal of Signaling Molecules in Cultured Primary Mouse Embryonic Fibroblasts

The ability to genetically remove specific components of various cell signalling cascades has been an integral tool in modern signal transduction analysis. One particular method to achieve this conditional deletion is via the use of the Cre-loxP system. This method involves flanking the gene of interest with loxP sites, which are specific recognition sequences for the Cre recombinase protein. Exposure of the so-called floxed (flanked by loxP site) DNA to this enzyme results in a Cre-mediated recombination event at the loxP sites, and subsequent excision of the intervening gene3. Several different methods exist to administer Cre recombinase to the site of interest. In this video, we demonstrate the use of an adenovirus containing the Cre recombinase gene to infect primary mouse embryonic fibroblasts (MEFs) obtained from embryos containing a floxed Rac1 allele1. Our rationale for selecting Rac1 MEFs for our experiments is that clear morphological changes can be seen upon deletion of Rac1, due to alterations in the actin cytoskeleton2,5. 72 hours following viral transduction and Cre expression, cells were stained using the actin dye phalloidin and imaged using confocal laser scanning microscopy. It was observed that MEFs which had been exposed to the adeno-Cre virus appeared contracted and elongated in morphology compared to uninfected cells, consistent with previous reports2,5. The adenovirus method of Cre recombinase delivery is advantageous as the adeno-Cre virus is easily available, and gene deletion via Cre in nearly 100% of the cells can be achieved with optimized adenoviral infection.

In this video we use an adenovirus carrying the Cre recombinase gene to infect primary mouse embryonic fibroblasts carrying a floxed Rac1 allele.

Adenovirus-mediata rimozione genetica di molecole di segnalazione in fibroblasti di topo coltivate primarie embrionali

The ability to genetically remove specific components of various cell signalling cascades has been an integral tool in modern signal transduction ...

Isolation and Culture of Cells from the Nephrogenic Zone of the Embryonic Mouse Kidney

Embryonic development of the kidney has been extensively studied both as a model for epithelial-mesenchymal interaction in organogenesis and to gain understanding of the origins of congenital kidney disease. More recently, the possibility of steering na&iuml;ve embryonic stem cells toward nephrogenic fates has been explored in the emerging field of regenerative medicine. Genetic studies in the mouse have identified several pathways required for kidney development, and a global catalog of gene transcription in the organ has recently been generated <a href="http://www.gudmap.org/">http://www.gudmap.org/</a>, providing numerous candidate regulators of essential developmental functions. Organogenesis of the rodent kidney can be studied in organ culture, and many reports have used this approach to analyze outcomes of either applying candidate proteins or knocking down the expression of candidate genes using siRNA or morpholinos. However, the applicability of organ culture to the study of signaling that regulates stem/progenitor cell differentiation versus renewal in the developing kidney is limited as cultured organs contain a compact extracellular matrix limiting diffusion of macromolecules and virus particles. To study the cell signaling events that influence the stem/progenitor cell niche in the kidney we have developed a primary cell system that establishes the nephrogenic zone or progenitor cell niche of the developing kidney ex vivo in isolation from the epithelial inducer of differentiation. Using limited enzymatic digestion, nephrogenic zone cells can be selectively liberated from developing kidneys at E17.5. Following filtration, these cells can be cultured as an irregular monolayer using optimized conditions. Marker gene analysis demonstrates that these cultures contain a distribution of cell types characteristic of the nephrogenic zone in vivo, and that they maintain appropriate marker gene expression during the culture period. These cells are highly accessible to small molecule and recombinant protein treatment, and importantly also to viral transduction, which greatly facilitates the study of candidate stem/progenitor cell regulator effects. Basic cell biological parameters such as proliferation and cell death as well as changes in expression of molecular markers characteristic of nephron stem/progenitor cells in vivo can be successfully used as experimental outcomes. Ongoing work in our laboratory using this novel primary cell technique aims to uncover basic mechanisms governing the regulation of self-renewal versus differentiation in nephron stem/progenitor cells.

In this report we describe a method for the isolation and culture of the progenitor cell niche from the embryonic mouse kidney that can be used to study signaling pathways regulating stem/progenitor cells of the developing kidney. These cultured cells are highly accessible to small molecule and recombinant protein treatment, and importantly also to viral transduction, which allows efficient manipulation of candidate pathways.

Isolamento e coltura di cellule dalla Zona nefrogenica del Rene embrionali di topo

Embryonic development of the kidney has been extensively studied both as a model for epithelial-mesenchymal interaction in organogenesis and  to gain ...

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.

Traslocazione polarizzato di proteine ​​fluorescenti in Xenopus</emEctoderma> in risposta alla segnalazione Wnt

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

Electroporation of Craniofacial Mesenchyme

Electroporation is an efficient method of delivering DNA and other charged macromolecules into tissues at precise time points and in precise locations. For example, electroporation has been used with great success to study neural and retinal development in Xenopus, chicken and mouse 1-10. However, it is important to note that in all of these studies, investigators were not targeting soft tissues. Because we are interested in craniofacial development, we adapted a method to target facial mesenchyme.
When we searched the literature, we found, to our surprise, very few reports of successful gene transfer into cartilaginous tissue. The majority of these studies were gene therapy studies, such as siRNA or protein delivery into chondrogenic cell lines, or, animal models of arthritis 11-13. In other systems, such as chicken or mouse, electroporation of facial mesenchyme has been challenging (personal communications, Dept of Craniofacial Development, KCL). We hypothesized that electroporation into procartilaginous and cartilaginous tissues in Xenopus might work better. In our studies, we show that gene transfer into the facial cartilages occurs efficiently at early stages (28), when the facial primordium is still comprised of soft tissue prior to cartilage differentiation.
Xenopus is a very accessible vertebrate system for analysis of craniofacial development. Craniofacial structures are more readily visible in Xenopus than in any other vertebrate model, primarily because Xenopus embryos are fertilized externally, allowing analyses of the earliest stages, and facilitating live imaging at single cell resolution, as well as reuse of the mothers 14. Among vertebrate models developing externally, Xenopus is more useful for craniofacial analysis than zebrafish, as Xenopus larvae are larger and easier to dissect, and the developing facial region is more accessible to imaging than the equivalent region in fish. In addition, Xenopus is evolutionarily closer to humans than zebrafish (&tilde;100 million years closer) 15. Finally, at these stages, Xenopus tadpoles are transparent, and concurrent expression of fluorescent proteins or molecules will allow easy visualization of the developing cartilages. We anticipate that this approach will allow us to rapidly and efficiently test candidate molecules in an in vivo model system.

Craniofacial cartilages develop in close contact with other tissues and are difficult to manipulate in live animals. We are using electroporation to deliver molecular tools during growth of the craniofacial skeleton while bypassing early embryonic effects. This approach will allow us to efficiently test candidate molecules in vivo.

Elettroporazione di Mesenchima craniofacciale

Electroporation is an efficient method of delivering DNA and other charged macromolecules into tissues at precise time points and in precise locations. ...

Efficient Differentiation of Mouse Embryonic Stem Cells into Motor Neurons

Direct differentiation of embryonic stem (ES) cells into functional motor neurons represents a promising resource to study disease mechanisms, to screen new drug compounds, and to develop new therapies for motor neuron diseases such as spinal muscular atrophy (SMA) and amyotrophic lateral sclerosis (ALS). Many current protocols use a combination of retinoic acid (RA) and sonic hedgehog (Shh) to differentiate mouse embryonic stem (mES) cells into motor neurons1-4. However, the differentiation efficiency of mES cells into motor neurons has only met with moderate success. We have developed a two-step differentiation protocol5 that significantly improves the differentiation efficiency compared with currently established protocols. The first step is to enhance the neuralization process by adding Noggin and fibroblast growth factors (FGFs). Noggin is a bone morphogenetic protein (BMP) antagonist and is implicated in neural induction according to the default model of neurogenesis and results in the formation of anterior neural patterning6. FGF signaling acts synergistically with Noggin in inducing neural tissue formation by promoting a posterior neural identity7-9. In this step, mES cells were primed with Noggin, bFGF, and FGF-8 for two days to promote differentiation towards neural lineages. The second step is to induce motor neuron specification. Noggin/FGFs exposed mES cells were incubated with RA and a Shh agonist, Smoothened agonist (SAG), for another 5 days to facilitate motor neuron generation. To monitor the differentiation of mESs into motor neurons, we used an ES cell line derived from a transgenic mouse expressing eGFP under the control of the motor neuron specific promoter Hb91. Using this robust protocol, we achieved 51&plusmn;0.8% of differentiation efficiency (n = 3; p &lt; 0.01, Student's t-test)5. Results from immunofluorescent staining showed that GFP+ cells express the motor neuron specific markers, Islet-1 and choline acetyltransferase (ChAT). Our two-step differentiation protocol provides an efficient way to differentiate mES cells into spinal motor neurons.

We developed a new protocol to improve efficiency of in vitro differentiation of mouse embryonic stem cells into motor neurons. The differentiated ES cells acquired motor neurons features as evidenced by expression of neuronal and motor neuron markers using immunohistochemical techniques.

Differenziazione efficiente di cellule staminali embrionali di topo in neuroni motori

Direct differentiation of embryonic stem (ES) cells into functional  motor neurons represents a promising resource to study disease mechanisms, to  screen ...

Preparation of Mouse Embryonic Fibroblast Cells Suitable for Culturing Human Embryonic and Induced Pluripotent Stem Cells

In general, human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs)1 can be cultured under variable conditions. However, it is not easy to establish an effective system for culturing these cells. Since the culture conditions can influence gene expression that confers pluripotency in hESCs and hiPSCs, the optimization and standardization of the culture method is crucial.
The establishment of hESC lines was first described by using MEFs as feeder cells and fetal bovine serum (FBS)-containing culture medium2. Next, FBS was replaced with knockout serum replacement (KSR) and FGF2, which enhances proliferation of hESCs3. Finally, feeder-free culture systems enable culturing cells on Matrigel-coated plates in KSR-containing conditioned medium (medium conditioned by MEFs)4. Subsequently, hESCs culture conditions have moved towards feeder-free culture in chemically defined conditions5-7. Moreover, to avoid the potential contamination by pathogens and animal proteins culture methods using xeno-free components have been established8.
To obtain improved conditions mouse feeder cells have been replaced with human cell lines (e.g. fetal muscle and skin cells9, adult skin cells10, foreskin fibroblasts11-12, amniotic mesenchymal cells13). However, the efficiency of maintaining undifferentiated hESCs using human foreskin fibroblast-derived feeder layers is not as high as that from mouse feeder cells due to the lower level of secretion of Activin A14. Obviously, there is an evident difference in growth factor production by mouse and human feeder cells.
Analyses of the transcriptomes of mouse and human feeder cells revealed significant differences between supportive and non-supportive cells. Exogenous FGF2 is crucial for maintaining self-renewal of hESCs and hiPSCs, and has been identified as a key factor regulating the expression of Tgf&beta;1, Activin A and Gremlin (a BMP antagonist) in feeder cells. Activin A has been shown to induce the expression of OCT4, SOX2, and NANOG in hESCs15-16.
For long-term culture, hESCs and hiPSCs can be grown on mitotically inactivated MEFs or under feeder-free conditions in MEF-CM (MEF-Conditioned Medium) on Matrigel-coated plates to maintain their undifferentiated state. Success of both culture conditions fully depends on the quality of the feeder cells, since they directly affect the growth of hESCs.
Here, we present an optimized method for the isolation and culture of mouse embryonic fibroblasts (MEFs), preparation of conditioned medium (CM) and enzyme-linked immunosorbent assay (ELISA) to assess the levels of Activin A within the media.

The quality of mouse embryonic fibroblasts (MEFs) is dictated by the right strain of mouse such as CF-1. Pluripotency-supportive MEFs and conditioned media (CM) obtained from these should contain optimal concentrations of Activin A, Gremlin and Tgf&beta;1 needed for the Activin/Nodal and FGF pathways to co-operatively maintain self-renewal and pluripotency.

Preparazione di cellule di fibroblasti embrionali di topo adatto per colture di cellule pluripotenti umane embrionali e staminali indotta

In general, human embryonic stem cells (hESCs) and human induced pluripotent stem cells (hiPSCs)1 can be cultured under variable conditions. However, it ...

A System for ex vivo Culturing of Embryonic Pancreas

The pancreas controls vital functions of our body, including the production of digestive enzymes and regulation of blood sugar levels1. Although in the past decade many studies have contributed to a solid foundation for understanding pancreatic organogenesis, important gaps persist in our knowledge of early pancreas formation2. A complete understanding of these early events will provide insight into the development of this organ, but also into incurable diseases that target the pancreas, such as diabetes or pancreatic cancer. Finally, this information will generate a blueprint for developing cell-replacement therapies in the context of diabetes.
 During embryogenesis, the pancreas originates from distinct embryonic outgrowths of the dorsal and ventral foregut endoderm at embryonic day (E) 9.5 in the mouse embryo3,4. Both outgrowths evaginate into the surrounding mesenchyme as solid epithelial buds, which undergo proliferation, branching and differentiation to generate a fully mature organ2,5,6. Recent evidences have suggested that growth and differentiation of pancreatic cell lineages, including the insulin-producing &beta;-cells, depends on proper tissue-architecture, epithelial remodeling and cell positioning within the branching pancreatic epithelium7,8. However, how branching morphogenesis occurs and is coordinated with proliferation and differentiation in the pancreas is largely unknown. This is in part due to the fact that current knowledge about these developmental processes has relied almost exclusively on analysis of fixed specimens, while morphogenetic events are highly dynamic.
 Here, we report a method for dissecting and culturing mouse embryonic pancreatic buds ex vivo on glass bottom dishes, which allow direct visualization of the developing pancreas (Figure 1). This culture system is ideally devised for confocal laser scanning microscopy and, in particular, live-cell imaging. Pancreatic explants can be prepared not only from wild-type mouse embryos, but also from genetically engineered mouse strains (e.g. transgenic or knockout), allowing real-time studies of mutant phenotypes. Moreover, this ex vivo culture system is valuable to study the effects of chemical compounds on pancreatic development, enabling to obtain quantitative data about proliferation and growth, elongation, branching, tubulogenesis and differentiation. In conclusion, the development of an ex vivo pancreatic explant culture method combined with high-resolution imaging provides a strong platform for observing morphogenetic and differentiation events as they occur within the developing mouse embryo.

A System for ex vivo Culturing of Embryonic Pancreas

Here, we describe a method for isolation, culture and manipulation of mouse embryonic pancreas. This represents an excellent ex vivo system for studying various aspects of pancreatic development, including morphogenesis, differentiation and growth. Pancreatic bud explants can be cultured for several days and used in a range of different applications, including whole-mount immunofluorescence and live imaging.

Un sistema per<em&gt; Ex vivo</emColtura&gt; del pancreas embrionale

The pancreas controls vital functions of our body,  including the production of digestive enzymes and regulation of blood sugar  levels1. Although in the ...