私たちはこの仕事に資金を提供するためのクイーンズ大学で生命科学と芸術と科学の学部に感謝。同様に、我々は必要な試薬、機器や技術サポートを提供するためにチン·サンウ研究室に感謝します。また、議論への貢献のために特にトニーQGEM 2011、彼に感謝します。

1。ワームの準備/洗濯<ol><li>若い成人11にワームを同期させます。 </li><li>ただOP50 E.の芝生をクリアした段階的なワーム5センチメートル走プレート上にSの基底のピペット2ミリリットル大腸菌 。ワームがバッファにプレート表面から洗浄されていることを確認するために、必要に応じてプレートを傾けて。 </li><li>マイクロ遠心チューブにワーム-S基底解のピペット1ミリリットル。 </li><li> 10秒は6,600 rpmでPicoFugeを使用するために遠心分離します。 </li><li>邪魔されずにワームのペレットを残して、Sの基礎を吸引。 </li><li>ワームを洗浄するために数回反転、マイクロ遠心チューブに1ミリリットルS基礎溶液を加える。 </li><li>手順1.4から1.6、さらに3回繰り返します。 </li><li> CAの最終体積に上清を吸引10秒5回目、今回のために遠心。 100μlの。 </li><li>各2μlのサンプルでは50〜250ワームが存在することを確認するためのNGMプレート上にワームのピペット2μlの。調整するSの基礎の小さいまたは大きい音量でワームを再懸濁することにより、必要に応じてSの基底におけるワームの濃度。 </li><li> 1までの時間ワームを洗浄した後すぐにアッセイでワームを使用してください。 </li></ol> 2。テストプレートを準備<ol><li> 4等しい象限に皿を分ける5センチメートルプレートの下側​​をマーキング。走化性寒天又はNGMを使用することができる。 3試験の最小値は、テストされている遺伝的系統ごとに必要とされています。 </li><li>原点を中心半径0.5センチメートル（ 図1）の円をマークします。 </li><li>サイトが起源と互いに等距離にあることを確認し、 &quot;コントロール&quot;のどちらか &quot;テスト&quot;のための &quot;T&quot;または &quot;C&quot;と各象限内のポイントをマークします。点が原点から少なくとも2cm離れてなければなりません。テスト象限と右上やコントロールなどの左下の象限（ 図1）のように左上と右下の象限をマーク。 </li></ol> 3。アッセイを実行する</P&gt; <ol><li>試験化合物および0.5 Mアジド（麻酔が象限に到達するとワームを逮捕するために使用される）の同等のボリュームを組み合わせることにより、試験液を混ぜる。 0.5 Mアジ化試験化合物を希釈するために使用される溶媒を組み合わせることにより、対照溶液を混ぜる。 </li><li>起源へのペレットからワーム溶液（1.8で調製した）（2線が交差）のピペット2μlの。 </li><li> 2 &quot;T&quot;のサイト上に試験溶液の直後に、ピペット2μlの。同様に、二つの &quot;C&quot;のサイト上に対照溶液と同じ量をピペット。 </li><li>ワームと匂い滴が寒天に吸収された後、蓋を交換して、プレートを反転。 </li><li> 60分後、4℃のインキュベーターにワームを配置。それはカウントすることができた場合にのみインキュベーターからプレートを取り外します。室温でワームのままにしておくと、彼らは再び結集することを可能にする。 </li><li>完全に内部のCIRCを越え各象限におけるワームの数を記録ル。 </li><li>試験および制御象限の両方で制御ソリューションを使って手順3.2から3.6を繰り返します。これは、制御板として機能します。そのような3つのプレートは適切なコントロールとして機能するように作られており、実行する必要があります。 </li></ol> 4。スコアの解釈/走指数の決定<ol><li>式（1）を使用して走化性指数を計算します。これは、-1.0と+1.0の間で走指数が得られます。 </li></ol> （1） 走化性指数=（テスト象限の両方で＃ワーム - 両方のコントロール象限＃ワーム）/（得点ワームの＃合計） +1.0スコアが目標に向かって最大限の魅力を示しており、化学的な目標を含む象限に到着ワームの100％を表します。 -1.0のインデックスは、最大反発力の証拠である。同様のアッセイ法は、既に3（ 表1）を用いてきた。 <ol start="2"><li>平均Chemotaxiを報告のインデックス（CI）及び平均値の標準誤差（SEM）。試験および対照プレートからのデータを比較するスチューデントのt検定を実行します。 </li></ol>

<ol>
	<li>Bargmann, C. I., Hartwieg, E., Horvitz, H. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Odorant-selective+genes+and+neurons+mediate+olfaction+in+C.+elegans.">Odorant-selective genes and neurons mediate olfaction in C. elegans.</a> Cell. 74, 515-527 (1993).</li><li>Bargmann, C. I., Horvitz, H. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemosensory+neurons+with+overlapping+functions+direct+chemotaxis+to+multiple+chemicals+in+C.+elegans.">Chemosensory neurons with overlapping functions direct chemotaxis to multiple chemicals in C. elegans.</a> Neuron. 7, 729-742 (1991).</li><li>Lee, J., Jee, C., McIntire, 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=Ethanol+preference+in+C.+elegans.">Ethanol preference in C. elegans.</a> Genes Brain Behav. 8, 578-585 (2009).</li><li>Swierczek, N. A., Giles, A. C., Rankin, C. H., Kerr, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-throughput+behavioral+analysis+in+C.+elegans.">High-throughput behavioral analysis in C. elegans.</a> Nat. Methods. 8, 592-598 (2011).</li><li>Ward, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemotaxis+by+the+nematode+Caenorhabditis+elegans:+identification+of+attractants+and+analysis+of+the+response+by+use+of+mutants.">Chemotaxis by the nematode Caenorhabditis elegans: identification of attractants and analysis of the response by use of mutants.</a> Proc. Natl. Acad. Sci. U.S.A. 70, 817-821 (1973).</li><li>Colbert, H. A., Bargmann, C. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Odorant-specific+adaptation+pathways+generate+olfactory+plasticity+in+C.+elegans.">Odorant-specific adaptation pathways generate olfactory plasticity in C. elegans.</a> Neuron. 14, 803-812 (1995).</li><li>Kauffman, A., Parsons, L., Stein, G., Wills, A., Kaletsky, R., Murphy, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=C.+elegans+Positive+Butanone+Learning,+Short-term,+and+Long-term+Associative+Memory+Assays.">C. elegans Positive Butanone Learning, Short-term, and Long-term Associative Memory Assays.</a> J. Vis. Exp. (49), e2490 (2011).</li><li>Troemel, E. R., Kimmel, B. E., Bargmann, C. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reprogramming+chemotaxis+responses:+sensory+neurons+define+olfactory+preferences+in+C.+elegans.">Reprogramming chemotaxis responses: sensory neurons define olfactory preferences in C. elegans.</a> Cell. 91, 161-169 (1997).</li><li>Pierce-Shimomura, J. T., Morse, T. M., Lockery, S. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+fundamental+role+of+pirouettes+in+Caenorhabditis+elegans+chemotaxis.">The fundamental role of pirouettes in Caenorhabditis elegans chemotaxis.</a> J Neurosci. 19, 9557-9569 (1999).</li><li>Frokjaer-Jensen, C., Ailion, M., Lockery, S. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ammonium-acetate+is+sensed+by+gustatory+and+olfactory+neurons+in+Caenorhabditis+elegans.">Ammonium-acetate is sensed by gustatory and olfactory neurons in Caenorhabditis elegans.</a> PLoS One. 3, e2467 (2008).</li><li>Porta-de-la-Riva, M., Fontrodona, L., Villanueva, A., Cer&#243;n, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Basic+Caenorhabditis+elegans+Methods:+Synchronization+and+Observation.">Basic Caenorhabditis elegans Methods: Synchronization and Observation.</a> J. Vis. Exp. (64), e4019 (2012).</li><li>Sengupta, P., Bargmann, C. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cell+fate+specification+and+differentiation+in+the+nervous+system+of+Caenorhabditis+elegans.">Cell fate specification and differentiation in the nervous system of Caenorhabditis elegans.</a> Dev. Genet. 18, 73-80 (1996).</li><li>Hart, 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=Behavior.">Behavior.</a> WormBook. , (1895).</li></ol>

我々は、開示することは何もありません。

走化性は、神経細胞及び細胞機構の複雑なセットによって制御されているが、容易にかつ客観的に走化性アッセイを用いて定量することができる。アッセイから最良の結果を得るためには、特定の重要なステップを払わなければなりません。まず、ワームをステージングすると、一貫性のある実験結果をもたらすに不可欠である。異なるライフステージでのワームは13異なる振る舞い...

ウォードは、最初の1973年5で走化性アッセイを開発し、それ以来、それははるかに到達するアプリケーションを持っています。神経生物学は、走化性アッセイのさまざまな方法を使って恩恵を受けた一つのフィールドである。嗅覚適応、学習および記憶の単純な形式は、C.において実証されている走化性アッセイ6を使用してエレガンス 。それらはまた、C.を示すために使用されているエレガンスは、エタノールワームの行動の可塑性を示していないだけ寛容結果を開発することができますが、それはまた、ワームは人間3でアルコール依存症の研究に非常に有用であることを示しています。アッセイは偶数℃の能力を実証するために開発されているelegansのアソシエーションが化学誘引物質と食品（OP50）7間ワームによって作られていることを示すことによって、短期および長期記憶を保存する。さらに、C.に関する広範な情報は、現在入手可能な与えられたelegansのゲノム、chemotaxiC.のS振る舞いエレガンスは、変異1,8を誘導することによって何度も変更されています。これは、Cの開発など多くのエキサイティングなエンジニアリングの可能性を、可能にバイオレメディエーションツールとしてエレガンス 。したがって、1973年に走化性アッセイの初期の開発以来、それが頻繁に変更され、さまざまな分野の中で謎を解明するために使用されています。 特定のアッセイは、標的に向かってワームが撮影した特定のルートを発見することを目的とした。この種の典型的アッセイはウォード5によって開発されました。三ワームを15分間溶かした寒天上に置いた。彼らの動きは、それらが、プレートの中央に誘引へ勾配アッププレートの周囲から旅し、彼らが残した痕跡によってトレースされた。プレート上のすべてのワームは、各試験の終了時にクロロホルムを使用して逮捕された。この方法の一つの子孫誘引し、コントロールとプレートの中央に単一のワームを置い起源2からT等しく反対の距離。 ピアース·下村ら 。走9に関わる動きの正確な性質を観察するアッセイ法を開発しました。個々のワームが誘引のソースで最高潮に達する、誘引または放射状の形の勾配の均一濃度を含むいずれかの9センチメートルペトリ皿に入れた。ワームを認識し、コンピュータ·ソフトウェア·プログラムが観察された挙動を記録した。アッセイは、ワームを確実にするために実行したとして自動的にシャーレを調整する段階と一緒に働いていた顕微鏡に取り付けられたビデオカメラの視野内に残った。このことから、より詳細な情報は、Cで表示されたピルエットの原因について、発見されましたエレガンス 。 ここで説明したものに類似の他のアッセイは、試験化合物へのワームの大規模な人口の応答をテストした。 2象限走化性アッセイはあったC.様々な神経細胞、受容体、およびシグナル伝達分子がでるという役割を探索するために使用される線虫は、種々の化合物1に曝した。 20-50の間に洗浄したワームが麻酔、アジ化ナトリウム（NaN 3を）と一緒に極両端誘引とコントロールとのプレートの中央付近に配置した。 60分後、-1.0から+1.0までの値を有する走化性インデックスが誘引またはコントロールに貼付されたどのくらいのワームの差に基づいて生成した。以前のアッセイは厳密に非運動ワームを評価するために失敗したものの、同じような走化インデックスは、この記事で報告されたアッセイで使用されていました。このアッセイは、さらに走化性に神経切除の効果を試験に適用した。 100-200ワームは、4つの象限3を含むプレートの中央に配置した場合に前述のアッセイの別の変形を行った。隣接象限のいずれかのテストが含まれていたり、物質を制御します。前のアッセイと同様に、ワームがスコアリングされる前に、アジ化ナトリウムの作用により固定化した。同様の方法は、C.の応答を評価する方法として、ここで説明されている種々の化合物に虫 。しかし、以下の方法は、唯一不動ワームから携帯分離閾値距離に合格したワームを評価するという利点を持っています。 他のアッセイは、不動のワームを無視するための同様のガイドラインを取り入れています。 Frøkjær·ジェンセンら 。揮発性および水溶性化合物10の両方をテストするために使用できる汎用性の高いアッセイを開発した。ペトリ皿を、4つの象限に分割した。上部と下部の象限は、溶媒を含まなかった。水を含んでいた左象限、右は誘引が含まれていました。水溶性化合物がAGAに直接配置されたのに対し、揮発性の匂い物質をテストする場合、分析物は、適切な象限にわたって、シャーレの蓋の上に置いたR。 Cの走化性応答を評価するための現在の存在のメソッド線虫は常に使用効率と精度の容易さを最適化するために洗練されている。アッセイは、ここで説明しながら、だから、ワームの最大数（最大スループット：Lee らによって実証スループットよりわずかに大きいプレート当たり250ワーム/時間、3）を評価する機能があり、この方法の本当の強さはある以前アッセイ（ 表1）の属性の多くの簡潔集大成。

<table border="1">
 <tbody>
 <tr>
 <td>Name of Reagent/Material</td>
 <td>Company</td>
 <td>Catalogue Number</td>
 <td>Comments</td>
 </tr>
 <tr>
 <td>S Basal (- cholesterol) [5.8 g NaCl; 1 M K phosphate buffer, pH 6.0; dH2O to 1 liter.] Autoclave</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>PicoFuge</td>
 <td>Stratagene</td>
 <td>400552</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Microscopes</td>
 <td>Leica</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Dissecting</td>
 <td>Leica</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>P1000 Pipette</td>
 <td>Gilson</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>P10 Pipette</td>
 <td>Gilson</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>0.5 M Sodium Azide</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Chemotaxis Agar [1.6% BBL-agar (Benton-Dickinson) or 2% Difco-agar. Autoclave. Add 5 mM potassium phosphate, pH 6.0; 1 mM CaCl2, 1 mM MgSO4]</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Ethanol/Distilled Water</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Test Compounds (eg. 0.5% diacetyl)</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>Agar</td>
 <td>Bio-Rad</td>
 <td>166-0600</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>NH4Cl</td>
 <td>Amresco</td>
 <td>CA97062-046</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>MOPS</td>
 <td>VWR</td>
 <td>CA12001-120</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>NH4OH</td>
 <td>BDH</td>
 <td>CABDH8641-2</td>
 <td>&nbsp;</td>
 </tr>
 <tr>
 <td>0.25% Tween 20</td>
 <td>Bio-Rad</td>
 <td>170-6531</td>
 <td>&nbsp;</td>
 </tr>
 </tbody>
</table>

c. elegans chemotaxis assay

多くの生物は、食料源を模索有害物質を避け、仲間を見つけるために走化性を使用しています。 線虫（Caenorhabditis elegans）は、印象的な走化性行動を持っています。 着臭剤のワームの応答を試験後ろ前提領域に置き、臭剤に応答誘発動きを観察することである。でも、多くの利用可能なアッセイで、有意なサンプルサイズを維持しながら、互いにワームの相互作用を最小限に抑えながら、対照および試験領域の両方に対して開始位置ワームを最適化が進行中1-10の作業のままである。ここで説明する方法は、Bargmann らによって開発されたアッセイ1を変更することによってこれらの問題に対処することを目的とする。ペトリ皿を4つの象限に分割され、 &quot;テスト&quot;二マーク二つの対向する象限は &quot;コントロール&quot;を付している。麻酔薬は、すべてのテストおよび制御部位に配置される。ワームがcircl、プレートの中央に配置されているeは非運動ワームは無視されることを保証するために原点を中心となった。彼らは試験および対照試料から等距離にあるように、4つの象限システムを利用ではなく、1 2または2 1にかかわらず、それらが始まった起源の側の、ワームの動きにバイアスを排除します。これは、ワームを遅らせたり、彼らの意図されたパスの不正確な解釈をもたらし、多くの遠回りルートを取るように強制することができ匂い、に対応するために他のワームのクラスタを通過することを余儀なくされているワームの問題を回避します。また、このメソッドは、より大きなサンプルサイズを有する研究者が無人の検定を実行し、割り当てられた時間の有効期限が切れた後のワームを獲得できるようにすることで、実用的な利点を示しています。

野生型（N2）C.を比較するODR-10（KY10）変異にエレガンス 。 私たちは、知られているCをジアセチル使用エレガンスは化学誘引物質、ジアセチル1,12の受容体を欠いた変異のそれに野生型ワームを比較する。 野生型（N2）ワームを走化指数は、エタノール、および0.839から0.100±0.066であった±0.031から0.5パーセントジアセチル。予?...

Watch this Scientific Journal Video about C. elegans Chemotaxis Assay at JoVE.com

C. elegans Chemotaxis Assay

定量の走化性応答の評価方法<em&gt;線虫（Caenorhabditis elegans）</em&gt;記載されている。走化指数（CI）は正確に特定のターゲットへのワームの応答を評価し、興味のある株と化合物との間の比較のプラットフォームとしての役割を果たすための方法として採用されました。

C. elegansの走化性アッセイ

Many organisms use chemotaxis to seek out food sources, avoid noxious substances, and find mates.  Caenorhabditis elegans has impressive chemotaxis ...

Research

JoVE Journal

Biology

C. elegans Chemotaxis Assay

45.0K ビュー.  Queen's University. 定量の走化性応答の評価方法線虫（Caenorhabditis elegans）記載されている。走化指数（CI）は正確に特定のターゲットへのワームの応答を評価し、興味のある株と化合物との間の比較のプラットフォームとしての役割を果たすための方法として採用されました。

ビデオ: C. elegans Chemotaxis Assay

Generation of Stable Transgenic C. elegans Using Microinjection

Transgenic Caenorhabditis elegans can be readily created via microinjection of a DNA plasmid solution into the gonad 1. The plasmid DNA rearranges to form extrachromosomal concatamers that are stably inherited, though not with the same efficiency as actual chromosomes 2. A gene of interest is co-injected with an obvious phenotypic marker, such as rol-6 or GFP, to allow selection of transgenic animals under a dissecting microscope. The exogenous gene may be expressed from its native promoter for cellular localization studies. Alternatively, the transgene can be driven by a different tissue-specific promoter to assess the role of the gene product in that particular cell or tissue. This technique efficiently drives gene expression in all tissues of C. elegans except for the germline or early embryo 3. Creation of transgenic animals is widely utilized for a range of experimental paradigms. This video demonstrates the microinjection procedure to generate transgenic worms. Furthermore, selection and maintenance of stable transgenic C. elegans lines is described.

This video demonstrates the technique of microinjection into the gonad of C. elegans to create transgenic animals.

マイクロインジェクションを使用して安定したトランスジェニック線虫の世代

Transgenic Caenorhabditis elegans can be readily created via microinjection of a DNA plasmid solution into the gonad 1.  The plasmid DNA rearranges to ...

生物学

Application of a C. elegans Dopamine Neuron Degeneration Assay for the Validation of Potential Parkinson's Disease Genes

Improvements to the diagnosis and treatment of Parkinson's disease (PD) are dependent upon knowledge about susceptibility factors that render populations at risk. In the process of attempting to identify novel genetic factors associated with PD, scientists have generated many lists of candidate genes, polymorphisms, and proteins that represent important advances, but these leads remain mechanistically undefined. Our work is aimed toward significantly narrowing such lists by exploiting the advantages of a simple animal model system. While humans have billions of neurons, the microscopic roundworm Caenorhabditis elegans has precisely 302, of which only eight produce dopamine (DA) in hemaphrodites. Expression of a human gene encoding the PD-associated protein, alpha-synuclein, in C. elegans DA neurons results in dosage and age-dependent neurodegeneration.
Worms expressing human alpha-synuclein in DA neurons are isogenic and express both GFP and human alpha-synuclein under the DA transporter promoter (Pdat-1). The presence of GFP serves as a readily visualized marker for following DA neurodegeneration in these animals. We initially demonstrated that alpha-synuclein-induced DA neurodegeneration could be rescued in these animals by torsinA, a protein with molecular chaperone activity 1. Further, candidate PD-related genes identified in our lab via large-scale RNAi screening efforts using an alpha-synuclein misfolding assay were then over-expressed in C. elegans DA neurons. We determined that five of seven genes tested represented significant candidate modulators of PD as they rescued alpha-synuclein-induced DA neurodegeneration 2. Additionally, the Lindquist Lab (this issue of JoVE) has performed yeast screens whereby alpha-synuclein-dependent toxicity is used as a readout for genes that can enhance or suppress cytotoxicity. We subsequently examined the yeast candidate genes in our C. elegans alpha-synuclein-induced neurodegeneration assay and successfully validated many of these targets 3, 4.
Our methodology involves generation of a C. elegans DA neuron-specific expression vector using recombinational cloning of candidate gene cDNAs under control of the Pdat-1 promoter. These plasmids are then microinjected in wild-type (N2) worms, along with a selectable marker for successful transformation. Multiple stable transgenic lines producing the candidate protein in DA neurons are obtained and then independently crossed into the alpha-synuclein degenerative strain and assessed for neurodegeneration, at both the animal and individual neuron level, over the course of aging.

Application of a C. elegans Dopamine Neuron Degeneration Assay for the Validation of Potential Parkinson&#039;s Disease Genes

This video demonstrates how to use C. elegans to assess dopaminergic neuron neurodegeneration as a model for Parkinson's disease. Furthermore, genetic screens are used to identify factors that either enhance degeneration or are neuroprotective.

潜在的なパーキンソン病の遺伝子を検証するための線虫のドーパミンニューロンの変性のアッセイのアプリケーション

Improvements to the diagnosis and treatment of Parkinson's disease (PD) are dependent upon knowledge about susceptibility factors that render populations ...

Paradigms for Pharmacological Characterization of C. elegans Synaptic Transmission Mutants

The nematode, Caenorhabditis elegans, has become an expedient model for studying neurotransmission. C. elegans is unique among animal models, as the anatomy and connectivity of its nervous system has been determined from electron micrographs and refined by pharmacological assays. In this video, we describe how two complementary neural stimulants, an acetylcholinesterase inhibitor, called aldicarb, and a gamma-aminobutyric acid (GABA) receptor antagonist, called pentylenetetrazole (PTZ), may be employed to specifically characterize signaling at C. elegans neuromuscular junctions (NMJs) and facilitate our understanding of antagonistic neural circuits.
Of 302 C. elegans neurons, nineteen GABAergic D-type motor neurons innervate body wall muscles (BWMs), while four GABAergic neurons, called RMEs, innervate head muscles. Conversely, thirty-nine motor neurons express the excitatory neurotransmitter, acetylcholine (ACh), and antagonize GABA transmission at BWMs to coordinate locomotion. The antagonistic nature of GABAergic and cholinergic motor neurons at body wall NMJs was initially determined by laser ablation and later buttressed by aldicarb exposure. Acute aldicarb exposure results in a time-course or dose-responsive paralysis in wild-type worms. Yet, loss of excitatory ACh transmission confers resistance to aldicarb, as less ACh accumulates at worm NMJs, leading to less stimulation of BWMs. Resistance to aldicarb may be observed with ACh-specific or general synaptic function mutants. Consistent with antagonistic GABA and ACh transmission, loss of GABA transmission, or a failure to negatively regulate ACh release, confers hypersensitivity to aldicarb. Although aldicarb exposure has led to the isolation of numerous worm homologs of neurotransmission genes, aldicarb exposure alone cannot efficiently determine prevailing roles for genes and pathways in specific C. elegans motor neurons. For this purpose, we have introduced a complementary experimental approach, which uses PTZ.
Neurotransmission mutants display clear phenotypes, distinct from aldicarb-induced paralysis, in response to PTZ. Wild-type worms, as well as mutants with specific inabilities to release or receive ACh, do not show apparent sensitivity to PTZ. However, GABA mutants, as well as general synaptic function mutants, display anterior convulsions in a time-course or dose-responsive manner. Mutants that cannot negatively regulate general neurotransmitter release and, thus, secrete excessive amounts of ACh onto BWMs, become paralyzed on PTZ. The PTZ-induced phenotypes of discrete mutant classes indicate that a complementary approach with aldicarb and PTZ exposure paradigms in C. elegans may accelerate our understanding of neurotransmission. Moreover, videos demonstrating how we perform pharmacological assays should establish consistent methods for C. elegans research.

This video demonstrates how to employ two neural stimulants, aldicarb and pentylenetetrazole (PTZ), in complementary ways to study synaptic function in the nematode, C. elegans. This complementary approach may also be used to shed light on evolutionarily conserved mechanisms for modulating neuronal synchrony and has implications for epilepsy and seizures.

C. elegansのシナプス伝達の変異体の薬理学的特性評価のためのパラダイム

The nematode, Caenorhabditis elegans, has become an expedient model for studying neurotransmission. C. elegans is unique among animal models, as the ...

Dissecting and Recording from The C. Elegans Neuromuscular Junction

Neurotransmission is the process by which neurons transfer information via chemical signals to their post-synaptic targets, on a rapid time scale. This complex process requires the coordinated activity of many pre- and post-synaptic proteins to ensure appropriate synaptic connectivity, conduction of electrical signals, targeting and priming of secretory vesicles, calcium sensing, vesicle fusion, localization and function of postsynaptic receptors and finally, recycling mechanisms. As neuroscientists it is our goal to elucidate which proteins function in each of these steps and understand their mechanisms of action. Electrophysiological recordings from synapses provide a quantifiable read out of the underlying electrical events that occur during synaptic transmission. By combining this technique with the powerful array of molecular and genetic tools available to manipulate synaptic proteins in C. elegans, we can analyze the resulting functional changes in synaptic transmission. 
The C. elegans NMJs formed between motor neurons and body wall muscles control locomotion, therefore, mutants with uncoordinated locomotory phenotypes (known as unc s) often perturb synaptic transmission at these synapses 1. Since unc mutants are maintained on a rich supply of a bacterial food source, they remain viable as long as they retain some pharyngeal pumping ability to ingest food. This, together with the fact that C. elegans exist as hermaphrodites, allows them to pass on mutant progeny without the need for elaborate mating behaviors. These attributes, coupled with our recent ability to record from the worms NMJs 2,3,7 make this an excellent model organism in which to address precisely how unc mutants impact neurotransmission. 
The dissection method involves immobilizing adult worms using a cyanoacrylic glue in order to make an incision in the worm cuticle exposing the NMJs. Since C. elegans adults are only 1 mm in length the dissection is performed with the use of a dissecting microscope and requires excellent hand-eye coordination. NMJ recordings are made by whole-cell voltage clamping individual body wall muscle cells and neurotransmitter release can be evoked using a variety of stimulation protocols including electrical stimulation, light-activated channel-rhodopsin-mediated depolarization 4 and hyperosmotic saline, all of which will be briefly described.

Application of electrophysiology to accessible synapses provides a quantifiable measure of synaptic activity, useful in analyzing synaptic mutants. This article describes a dissection method used to expose the neuromuscular junctions (NMJ) of Caenorhabditis elegans (C. elegans) and briefly discusses some of the uses to which this preparation can be applied.

解離性とC. elegansの神経筋接合部から録音する

Neurotransmission is the process by which neurons transfer information via chemical signals to their post-synaptic targets, on a rapid time scale.   This ...

Generation of Transgenic C. elegans by Biolistic Transformation

The number of laboratories using the free living nematode C. elegans is rapidly growing. The popularity of this biological model is attributed to a rapid generation time and short life span, easy and inexpensive maintenance, fully sequenced genome, and array of RNAi resources and mutant animals. Additionally, analysis of the C. elegans genome revealed a great similarity between worms and higher vertebrates, which suggests that research in worms could be an important adjunct to studies performed in whole mice or cultured cells. A powerful and important part of worm research is the ability to use transgenic animals to study gene localization and function. Transgenic animals can be created either via microinjection of the worm germline or through the use of biolistic bombardment. Bombardment is a newer technique and is less familiar to a number of labs. Here we describe a simple protocol to generate transgenic worms by biolistic bombardment with gold particles using the Bio-Rad PDS-1000 system. Compared with DNA microinjection into hermaphrodite germline, this protocol has the advantage of not requiring special skills from the operator with regards to identifying worm anatomy or performing microinjection. Further multiple transgenic lines are usually obtained from a single bombardment. Also in contrast to microinjection, biolistic bombardment produces transgenic animals with both extrachromosomal arrays and integrated transgenes. The ability to obtain integrated transgenic lines can avoid the use of mutagenic protocols to integrate foreign DNA. In conclusion, biolistic bombardment can be an attractive method for the generation of transgenic animals, especially for investigators not interested in investing the time and effort needed to become skilled at microinjection.

Generation of Transgenic C. elegans by Biolistic Transformation

Transgenic worms are commonly used in C. elegans research. Described is a simple, yet effective, protocol to introduce transgenes into worms using biolistic bombardment with DNA-coated gold particles. The effort involved and results of bombardment compare favorably with microinjection for the generation of transgenic animals.

トランスジェニックの世代 C.エレガンスバイオリスティック変換による

The number of laboratories using the free living nematode C. elegans is rapidly growing. The popularity of this biological model is attributed to a rapid ...

RNAi Screening to Identify Postembryonic Phenotypes in C. elegans

C. elegans has proven to be a valuable model system for the discovery and functional characterization of many genes and gene pathways1. More sophisticated tools and resources for studies in this system are facilitating continued discovery of genes with more subtle phenotypes or roles. 
Here we present a generalized protocol we adapted for identifying C. elegans genes with postembryonic phenotypes of interest using RNAi2. This procedure is easily modified to assay the phenotype of choice, whether by light or fluorescence optics on a dissecting or compound microscope. This screening protocol capitalizes on the physical assets of the organism and molecular tools the C. elegans research community has produced. As an example, we demonstrate the use of an integrated transgene that expresses a fluorescent product in an RNAi screen to identify genes required for the normal localization of this product in late stage larvae and adults. First, we used a commercially available genomic RNAi library with full-length cDNA inserts. This library facilitates the rapid identification of multiple candidates by RNAi reduction of the candidate gene product. Second, we generated an integrated transgene that expresses our fluorecently tagged protein of interest in an RNAi-sensitive background. Third, by exposing hatched animals to RNAi, this screen permits identification of gene products that have a vital embryonic role that would otherwise mask a post-embryonic role in regulating the protein of interest. Lastly, this screen uses a compound microscope equipped for single cell resolution.

RNAi Screening to Identify Postembryonic Phenotypes in C. elegans

We describe a sensitized method to identify postembryonic regulators of protein expression and localization in C. elegans using an RNAi-based genomic screen and an integrated transgene that expresses a functional, fluorescently tagged protein.

の後胚表現型を識別するためのRNAiスクリーニング C.エレガンス</em

C. elegans has proven to be a valuable model system for the discovery and functional characterization of many genes and gene pathways1. More sophisticated ...

Basic Caenorhabditis elegans Methods: Synchronization and Observation

Research into the molecular and developmental biology of the nematode Caenorhabditis elegans was begun in the early seventies by Sydney Brenner and it has since been used extensively as a model organism 1. C. elegans possesses key attributes such as simplicity, transparency and short life cycle that have made it a suitable experimental system for fundamental biological studies for many years 2. Discoveries in this nematode have broad implications because many cellular and molecular processes that control animal development are evolutionary conserved 3.
C. elegans life cycle goes through an embryonic stage and four larval stages before animals reach adulthood. Development can take 2 to 4 days depending on the temperature. In each of the stages several characteristic traits can be observed. The knowledge of its complete cell lineage 4,5 together with the deep annotation of its genome turn this nematode into a great model in fields as diverse as the neurobiology 6, aging 7,8, stem cell biology 9 and germ line biology 10. 
An additional feature that makes C. elegans an attractive model to work with is the possibility of obtaining populations of worms synchronized at a specific stage through a relatively easy protocol. The ease of maintaining and propagating this nematode added to the possibility of synchronization provide a powerful tool to obtain large amounts of worms, which can be used for a wide variety of small or high-throughput experiments such as RNAi screens, microarrays, massive sequencing, immunoblot or in situ hybridization, among others. 
Because of its transparency, C. elegans structures can be distinguished under the microscope using Differential Interference Contrast microscopy, also known as Nomarski microscopy. The use of a fluorescent DNA binder, DAPI (4',6-diamidino-2-phenylindole), for instance, can lead to the specific identification and localization of individual cells, as well as subcellular structures/defects associated to them.

Basic Caenorhabditis elegans Methods: Synchronization and Observation

The easiness of maintaining and propagating the nematode C. elegans make it a nice model organism to work with. The possibility of synchronizing worms allows the work with a significant amount of subjects at the same developmental stage, what facilitates the study of one particular process in many animals.

基本的な<em&gt;線虫Caenorhabditis elegans</em&gt;方法：同期との観測

Research into the molecular and developmental biology of the nematode Caenorhabditis elegans was begun in the early seventies by Sydney Brenner and it has ...

A Method for Culturing Embryonic C. elegans Cells

C. elegans is a powerful model system, in which genetic and molecular techniques are easily applicable. Until recently though, techniques that require direct access to cells and isolation of specific cell types, could not be applied in C. elegans. This limitation was due to the fact that tissues are confined within a pressurized cuticle which is not easily digested by treatment with enzymes and/or detergents. Based on early pioneer work by Laird Bloom, Christensen and colleagues 1 developed a robust method for culturing C. elegans embryonic cells in large scale. Eggs are isolated from gravid adults by treatment with bleach/NaOH and subsequently treated with chitinase to remove the eggshells. Embryonic cells are then dissociated by manual pipetting and plated onto substrate-covered glass in serum-enriched media. Within 24 hr of isolation cells begin to differentiate by changing morphology and by expressing cell specific markers. C. elegans cells cultured using this method survive for up 2 weeks in vitro and have been used for electrophysiological, immunochemical, and imaging analyses as well as they have been sorted and used for microarray profiling.

A Method for Culturing Embryonic C. elegans Cells

We describe here a revised protocol for large-scale culture of embryonic C. elegans cells. Embryonic C. elegans cells cultured in vitro using this method, appear to differentiate and recapitulate the expression of genes in a cell specific manner. Techniques that require direct access to the cells or isolation of specific cell types from the other tissues can be applied on C. elegans cultured cells.

培養胚のための方法<em&gt; C.虫</em&gt;細胞

C. elegans is a powerful model system, in which genetic and molecular techniques are easily applicable. Until recently though, techniques that require ...

Antibody Staining in C. Elegans Using &quot;Freeze-Cracking&quot;

To stain C. elegans with antibodies, the relatively impermeable cuticle must be bypassed by chemical or mechanical methods. "Freeze-cracking" is one method used to physically pull the cuticle from nematodes by compressing nematodes between two adherent slides, freezing them, and pulling the slides apart. Freeze-cracking provides a simple and rapid way to gain access to the tissues without chemical treatment and can be used with a variety of fixatives. However, it leads to the loss of many of the specimens and the required compression mechanically distorts the sample. Practice is required to maximize recovery of samples with good morphology. Freeze-cracking can be optimized for specific fixation conditions, recovery of samples, or low non-specific staining, but not for all parameters at once. For antibodies that require very hard fixation conditions and tolerate the chemical treatments needed to chemically permeabilize the cuticle, treatment of intact nematodes in solution may be preferred. If the antibody requires a lighter fix or if the optimum fixation conditions are unknown, freeze-cracking provides a very useful way to rapidly assay the antibody and can yield specific subcellular and cellular localization information for the antigen of interest.

Antibody Staining in C. Elegans Using &quot;Freeze-Cracking&quot;

"Freeze-cracking," a method for exposing the inner tissues of the nematode C. elegans to antibodies for protein localization, is demonstrated.

抗体染色中<em&gt; C.虫</em&gt;「フリーズクラッキング」使用

To stain C.  elegans with antibodies, the relatively impermeable cuticle must be  bypassed by chemical or mechanical methods.  "Freeze-cracking" is one ...

Measuring the Effects of Bacteria on C. Elegans Behavior Using an Egg Retention Assay

C. elegans egg-laying behavior is affected by environmental cues such as osmolarity1 and vibration2. In the total absence of food C. elegans also cease egg-laying and retain fertilized eggs in their uterus3. However, the effect of different sources of food, especially pathogenic bacteria and particularly Enterococcus faecalis, on egg-laying
	behavior is not well characterized. The egg-in-worm (EIW) assay is a useful tool to quantify the effects of different types of bacteria, in this case E. faecalis, on egg- laying behavior.
	
	EIW assays involve counting the number of eggs retained in the uterus of C. elegans4. The EIW assay involves bleaching staged, gravid adult C. elegans to remove the cuticle and separate the retained eggs from the animal. Prior to bleaching, worms are exposed to bacteria (or any type of environmental cue) for a fixed period of time. After bleaching, one is very easily able to count the number of eggs retained inside the uterus of the worms. In this assay, a quantifiable increase in egg retention after E. faecalis exposure can be easily measured. The EIW assay is a behavioral assay that may be used to screen for potentially pathogenic bacteria or the presence of environmental toxins. In addition, the EIW assay may be a tool to screen for drugs that affect neurotransmitter signaling since egg-laying behavior is modulated by neurotransmitters such as serotonin and acetylcholine5-9.

Measuring the Effects of Bacteria on C. Elegans Behavior Using an Egg Retention Assay

An egg-in-worm (EIW) assay is a useful method to quantify egg-laying behavior. Alterations in egg laying can be a behavioral response of the model organism Caenorhabditis elegans to potentially harmful environmental substances such as those produced by pathogenic bacteria.

上の細菌の影響を測定する<em&gt; C.エレガンス</em卵保持アッセイを用いて&gt;行動

C. elegans egg-laying behavior is  affected by environmental cues such as osmolarity1 and  vibration2. In the total absence of food C. elegans also cease ...