Name: xenopus oocytes: optimized methods for microinjection, removal of follicular cell layers, and fast solution changes in electrophysiological experiments
Uploaded: 2016-12-31T15:00:00
Description: Watch this Scientific Journal Video about Xenopus Oocytes: Optimized Methods for Microinjection, Removal of Follicular Cell Layers, and Fast Solution Changes in Electrophysiological Experiments at JoV

This work was supported by the Swiss National Science Foundation grant 315230_156929/1. M.C.M. is a recipient of a fellowship (Beca Chile Postdoctorado from CONICYT, Ministerio de Educacion, Chile).

Animal experiments have been approved by the local committee of the Canton Bern Kantonstierarzt, Kantonaler Veterin&#228;rdienst Bern (BE85/15).
1. Preparation of Xenopus Oocytes
<ol>
	<li>Maintain frogs (Xenopus laevis) on a 12 h/12 h light/dark cycle in water that is strictly kept at 20 &#176;C.</li>
	<li>Remove the lobes of the ovaries from female frogs9. 
	NOTE: The removal of the lobes is a stimulus for regeneration, and often the quality of the oocytes...

<ol>
	<li>Gurdon, J. B., Lane, C. D., Woodland, H. R., Marbaix, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+frog+eggs+and+oocytes+for+the+study+of+messenger+RNA+and+its+translation+in+living+cells.">Use of frog eggs and oocytes for the study of messenger RNA and its translation in living cells.</a> Nature. 233 (5316), 177-182 (1971).</li><li>Soreq, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+biosynthesis+of+biologically+active+proteins+in+mRNA-microinjected+Xenopus+oocytes.">The biosynthesis of biologically active proteins in mRNA-microinjected Xenopus oocytes.</a> CRC Crit Rev Biochem. 18 (3), 199-238 (1985).</li><li>Sigel, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+Xenopus+oocytes+for+the+functional+expression+of+plasma+membrane+proteins.">Use of Xenopus oocytes for the functional expression of plasma membrane proteins.</a> J Membr Biol. 117 (3), 201-221 (1990).</li><li>Dascal, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+use+of+Xenopus+oocytes+for+the+study+of+ion+channels.">The use of Xenopus oocytes for the study of ion channels.</a> CRC Crit Rev Biochem. 22 (4), 317-387 (1987).</li><li>Sigel, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Properties+of+single+sodium+channels+translated+by+Xenopus+oocytes+after+injection+with+messenger+ribonucleic+acid.">Properties of single sodium channels translated by Xenopus oocytes after injection with messenger ribonucleic acid.</a> J Physiol. 386, 73-90 (1987).</li><li>Sigel, E., Minier, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Xenopus+oocyte:+system+for+the+study+of+functional+expression+and+modulation+of+proteins.">The Xenopus oocyte: system for the study of functional expression and modulation of proteins.</a> Mol Nutr Food Res. 49 (3), 228-234 (2005).</li><li>Colman, A., Hames, B. D., Higgins, S. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Expression+of+exogenous+DNA+in+Xenopus+oocytes.">Expression of exogenous DNA in Xenopus oocytes.</a> Transcription and Translation'A Practical Approach. , 49-69 (1984).</li><li>Sive, H. L., Grainger, R. M., Harland, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Defolliculation+of+Xenopus+oocytes.">Defolliculation of Xenopus oocytes.</a> Cold Spring Harb Protoc. 2010 (12), 1377-1379 (2010).</li><li>Smart, T. G., Krishek, B. J., Boulton, A. A., Baker, ., Wolfgang, W. a. l. z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Xenopus+oocyte+microinjection+and+ion-channel+expression.">Xenopus oocyte microinjection and ion-channel expression.</a> Patch-Clamp Applications and Protocols. , 259-305 (1995).</li><li>Maldifassi, M. C., Baur, R., Sigel, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functional+sites+involved+in+modulation+of+the+GABA+receptor+channel+by+the+intravenous+anesthetics+propofol,+etomidate+and+pentobarbital.">Functional sites involved in modulation of the GABA receptor channel by the intravenous anesthetics propofol, etomidate and pentobarbital.</a> Neuropharmacology. 105, 207-214 (2016).</li><li>Maldifassi, M. C., Baur, R., Pierce, D., Nourmahnad, A., Forman, S. A., Sigel, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel+positive+allosteric+modulators+of+GABAA+receptors+with+anesthetic+activity.">Novel positive allosteric modulators of GABAA receptors with anesthetic activity.</a> Sci Rep. 6, 25943 (2016).</li><li>Wongsamitkul, N., Baur, R., Sigel, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Towards+understanding+functional+properties+and+subunit+arrangement+of+&#945;4&#946;2&#948;+GABAA+receptors.">Towards understanding functional properties and subunit arrangement of &#945;4&#946;2&#948; GABAA receptors.</a> J Biol Chem. 291 (35), 18474-18483 (2016).</li><li>Burgunder, J. M., 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=Novel+chloride+channel+mutations+leading+to+mild+myotonia+among+Chinese.">Novel chloride channel mutations leading to mild myotonia among Chinese.</a> Neuromuscul Disord. 18 (8), 633-640 (2008).</li><li>Steinmann, M. E., Gonzalez-Salgado, A., Butikofer, P., Maser, P., Sigel, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+heteromeric+potassium+channel+involved+in+the+modulation+of+the+plasma+membrane+potential+is+essential+for+the+survival+of+African+trypanosomes.">A heteromeric potassium channel involved in the modulation of the plasma membrane potential is essential for the survival of African trypanosomes.</a> FASEB J. 29 (8), 3228-3237 (2015).</li><li>Gonzalez-Salgado, A., 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=myo-Inositol+uptake+is+essential+for+bulk+inositol+phospholipid+but+not+glycosylphosphatidylinositol+synthesis+in+Trypanosoma+brucei.">myo-Inositol uptake is essential for bulk inositol phospholipid but not glycosylphosphatidylinositol synthesis in Trypanosoma brucei.</a> J Biol Chem. 287 (16), 13313-13323 (2012).</li><li>Gonzalez-Salgado, A., 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=Trypanosoma+brucei+Bloodstream+Forms+Depend+upon+Uptake+of+myo-Inositol+for+Golgi+Complex+Phosphatidylinositol+Synthesis+and+Normal+Cell+Growth.">Trypanosoma brucei Bloodstream Forms Depend upon Uptake of myo-Inositol for Golgi Complex Phosphatidylinositol Synthesis and Normal Cell Growth.</a> Eukaryot Cell. 14 (6), 616-624 (2015).</li><li>Wu, M., Gerhart, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Raising+Xenopus+in+the+laboratory.">Raising Xenopus in the laboratory.</a> Methods Cell Biol. 36, 3-18 (1991).</li><li>Gurdon, J. B., Wilt, F. H., Wessels, N. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=American+clawed+frogs.">American clawed frogs.</a> Methods in developmental biology. , 75-84 (1967).</li><li>Elsner, H. A., Honck, H. H., Willmann, F., Kreienkamp, H. J., Iglauer, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Poor+quality+of+oocytes+from+Xenopus+laevis+used+in+laboratory+experiments:+prevention+by+use+of+antiseptic+surgical+technique+and+antibiotic+supplementation.">Poor quality of oocytes from Xenopus laevis used in laboratory experiments: prevention by use of antiseptic surgical technique and antibiotic supplementation.</a> Comp Med. 50 (2), 206-211 (2000).</li><li>Green, S. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Factors+affecting+oogenesis+in+the+South+African+clawed+frog+(Xenopus+laevis).">Factors affecting oogenesis in the South African clawed frog (Xenopus laevis).</a> Comp Med. 52 (4), 307-312 (2002).</li><li>Dumont, J. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oogenesis+in+Xenopus+laevis+(Daudin).+I.+Stages+of+oocyte+development+in+laboratory+maintained+animals.">Oogenesis in Xenopus laevis (Daudin). I. Stages of oocyte development in laboratory maintained animals.</a> J Morphol. 136 (2), 153-179 (1972).</li><li>Kressmann, A., Celis, J. E., Grassmann, A., Loyter, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Birnstiel+M.L.+Surrogate+genetics.">Birnstiel M.L. Surrogate genetics.</a> Transfer of Cell Constituents into Eucaryotic Cells. , 388-407 (1980).</li><li>Middendorp, S. J., Maldifassi, M. C., Baur, R., Sigel, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Positive+modulation+of+synaptic+and+extrasynaptic+GABAA+receptors+by+an+antagonist+of+the+high+affinity+benzodiazepine+binding+site.">Positive modulation of synaptic and extrasynaptic GABAA receptors by an antagonist of the high affinity benzodiazepine binding site.</a> Neuropharmacology. 95, 459-467 (2015).</li><li>Dumont, J. N., Brummett, A. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oogenesis+in+Xenopus+laevis+(Daudin).+V.+Relationships+between+developing+oocytes+and+their+investing+follicular+tissues.">Oogenesis in Xenopus laevis (Daudin). V. Relationships between developing oocytes and their investing follicular tissues.</a> J Morphol. 155 (1), 73-97 (1978).</li><li>Dascal, N., Landau, E. M., Lass, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Xenopus+oocyte+resting+potential,+muscarinic+responses+and+the+role+of+calcium+and+guanosine+3',5'-cyclic+monophosphate.">Xenopus oocyte resting potential, muscarinic responses and the role of calcium and guanosine 3',5'-cyclic monophosphate.</a> J Physiol. 352, 551-574 (1984).</li><li>Buckingham, S. D., Pym, L., Sattelle, D. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oocytes+as+an+expression+system+for+studying+receptor/channel+targets+of+drugs+and+pesticides.">Oocytes as an expression system for studying receptor/channel targets of drugs and pesticides.</a> Methods Mol Biol. 322, 331-345 (2006).</li><li>Sigel, E., Baur, R., Trube, G., M&#246;hler, H., Malherbe, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+effect+of+subunit+combination+of+rat+brain+GABAA+receptors+on+channel+function.">The effect of subunit combination of rat brain GABAA receptors on channel function.</a> Neuron. 5, 703-711 (1990).</li></ol>

The methods described in this article deviate from those used traditionally7-9. It is standard to expose the lobes of the ovary to a 1 to 2 h collagenase treatment8; isolate undamaged, denuded oocytes; and inject them with mRNA using commercial injection devices. This classical procedure has the following drawbacks: 1) Oocytes are likely to be damaged by the long exposure to high concentrations of collagenase. 2) The unstable denuded oocytes must be stored until the experiment. 3) Denuded oocytes ar...

Xenopus oocytes are widely used as an expression system (References 2 - 3, and references therein). They are able to properly assemble and incorporate functionally active multisubunit proteins into their plasma membranes. Using this system, it is possible to functionally investigate membrane proteins alone or in combination with other proteins, in order to study the properties of mutated, chimeric, or concatenated proteins, and to screen potential drugs.
Advantages of using oocytes over other heterologous expression systems include the simple handling of the giant cells, the high proportion of cells expressing foreign genetic information, the simple control of the environment of the oocyte by means of bath perfusion, and the control of the membrane potential.
The drawback of this expression system is the seasonal variation observed in many laboratories17-20. The reason for this variation is far from clear. Additionally, the quality of oocytes is often observed to vary strongly. Traditional methods7-9 have included the isolation of ovary lobes, the exposure of ovary lobes to collagenase for some h, the selection of denuded oocytes, and the oocyte microinjection. Here, a number of alternative, fast procedures are reported that have allowed us to work with this expression system for more than 30 years with no seasonal variation and little variation in oocyte quality.
The modified and improved methods described here for the isolation of oocytes, microinjection with cRNA, and removal of follicular cell layers can be used for the expression of any protein of choice in the Xenopus oocyte. The very simple method for fast solution changes of the medium around the oocyte may be applied to the study of any ligand-gated ion channel and of carriers.

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xenopus oocytes: optimized methods for microinjection, removal of follicular cell layers, and fast solution changes in electrophysiological experiments

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

Xenopus oocytes were mechanically singled out using a platinum loop (Figure 1). The oocytes were microinjected with mRNA coding for the GABAA receptor subunits &#945;4, &#946;2, &#948;, 0.5:0.5:2.5 fmol/oocyte (Figure 2). After 4 d, follicular cell layers were removed (Figure 3). Oocytes were voltage clamped at -80 mV and exposed to increasing concentrations of &#947;-aminobutyric acid (GABA) in t...

Watch this Scientific Journal Video about Xenopus Oocytes: Optimized Methods for Microinjection, Removal of Follicular Cell Layers, and Fast Solution Changes in Electrophysiological Experiments at JoV

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

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

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

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

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

Electrophysiological Methods for Recording Synaptic Potentials from the NMJ of Drosophila Larvae

In this video, we describe the electrophysiological methods for recording synaptic transmission at the neuromuscular junction (NMJ) of Drosophila larva. ...

Visualizing RNA Localization in Xenopus Oocytes

Visualizing RNA Localization in Xenopus Oocytes

RNA localization is a conserved mechanism of establishing cell polarity.  Vg1 mRNA localizes to the vegetal pole of Xenopus laevis oocytes and acts to ...

Fertilization of Xenopus oocytes using the Host Transfer Method

Fertilization of Xenopus oocytes using the Host Transfer Method

Studying the contribution of maternally inherited molecules to vertebrate early development is often hampered by the time and expense necessary to ...

Patch Clamp and Perfusion Techniques for Studying Ion Channels Expressed in Xenopus oocytes

Patch Clamp and Perfusion Techniques for Studying Ion Channels Expressed in Xenopus oocytes

The protocol presented here is designed to study the activation of the large conductance, voltage- and Ca2+-activated K+ (BK) channels. The protocol may ...

Activation of Apoptosis by Cytoplasmic Microinjection of Cytochrome c

Activation of Apoptosis by Cytoplasmic Microinjection of Cytochrome c

Apoptosis, or programmed cell death, is a conserved and highly regulated pathway by which cells die1.  Apoptosis can be triggered when cells encounter a ...

Optimized Staining and Proliferation Modeling Methods for Cell Division Monitoring using Cell Tracking Dyes

Fluorescent cell tracking dyes, in combination with flow and image cytometry, are powerful tools with which to study the interactions and fates of ...

Yeast Luminometric and Xenopus Oocyte Electrophysiological Examinations of the Molecular Mechanosensitivity of TRPV4

Yeast Luminometric and Xenopus Oocyte Electrophysiological Examinations of the Molecular Mechanosensitivity of TRPV4

TRPV4 (Transient Receptor Potentials, vanilloid family, type 4) is widely expressed in vertebrate tissues and is activated by several stimuli, including ...