소콜 실험실에서 연구는 건강의 국가 Institues 후원됩니다.

Xenopus 계란 1.에서는 체외의 수정 <ol><li> 실험 전에 인간 chorionic 생식 샘 자극 호르몬 (400 단위 / 개구리) 12 시간과 함께 주입했다 암컷 개구리의 알을 얻을 수 있습니다. </li><li> 1 X 마크의 변경 링어 달걀 솔루션 (MMR) 10 해부 testis의 작은 조각으로 체외에서 그들을 비옥의 소량의 (0.5-1 ML)로 플레이스 계란. 2-3 분 후, 계란의 전체 표면을 커버하기 위해 0.1 X MMR을 추가합니다. HCL (수산화 나트륨과 산도 8 조정) - 20 분, 달걀 젤리 코트는 3 % 시스테인에 의해 제거됩니다. 계란은 주사에 대한 (13 ° C) 0.1 X MMR 세 번와 세탁과 감기 인큐베이터에 남아 있습니다. </li><li> 수정된 달걀은 2-4 셀 단계 개발에 사용할 수 있습니다. 주사 들어, 배아는 3 % Ficoll, 0.5 X MMR을 포함하고있는 솔루션으로 전송됩니다. </li></ol> 2. RNA의 Microinjection <ol><li> RNAS는 mMessage mMachine 키트 (앰비온)를 사용하여 선형 DNA 템플릿에서 합성 및 0.1-1 μg / μl의 주식 농도에서 RNase 무료 물로 희석하고 있습니다. 주사에 대한 RNAS 최적의 복용은 파일럿 실험에서 결정됩니다. Diversin - RFP, 멤브레인 마커 GFP - CAAX 8 Frizzled에 대한 RNAS는 사출 당 0.1-1 NG에 사용됩니다. </li><li> 주사 바늘은 바늘 연삭기와 다음 모세관과에서 바늘 풀러와 함께 준비하고 있습니다. 주입하기 전에 각각의 주사 바늘을 주입 액체 당 10 NL를 꺼내 물로 교정입니다. </li><li> 주사 들어, 배아는 3 % Ficoll, 0.5 X MMR의 큰 비말에 플라스틱 접시에 게재됩니다. RNA 솔루션 중 하나 microliter은 Narishige microinjector과 주사 바늘로 빨려입니다. RNA 10 NL은 8 세포 배아 2-3 회 동물 blastomeres로 주입됩니다. 주입 배아는 12 잘 판의 우물에 전송됩니다. </li></ol> 3. 준비 Ectodermal의 Explants <ol><li> 주입된 배아가 초기 gastrula 단계에 도달하면, 그들은 1퍼센트 아가로 오스와 코팅 3cm 플라스틱 접시에 0.6 X MMR 솔루션으로 전송됩니다. Vitelline 막는 포셉 한 쌍의와 함께 수동으로 제거됩니다. Ectodermal의 explants은 텅스텐 바늘과 hairloop를 사용하여 배아에서 excised 수 있습니다. </li><li> Ectodermal의 explants는 유리관에 양도와 인산 3.7 %의 포름 알데히드와 함께 고정 30 분 (PBS) 호수 버퍼입니다. 고정 explants는 PBS 세 번 (10 분마다)로 세탁합니다. DAPI는 핵을 얼룩이 세 번째 세척에 포함되어 있습니다. </li><li> Explants은 슬라이드 유리에 장착된 있습니다. 스카치 테이프의 두 스트립은 슬라이드에 붙어 있으며, explants는 두 스트립 사이에 위치하고 있습니다. explants의 외부 표면에 색소 때문에, explants의 안쪽은 현미경의 목표를 직면한다. 장착 솔루션 11 (PBS 25 MG / ML DABCO, 변색 방지 시약을 포함하여 70 %의 글리세롤)의 2-3 20 μl 방울을 추가합니다. 위에 coverslip 놔. </li></ol> 4. 형광 현미경 Explants의 이미징 <ol><li> 샘플은 적절한 필터를 자이스 혈구 Axioplan 형광 현미경으로 볼 수 있습니다. </li><li> 이미지가 여러 독립적인 explants에서 특정 비행기를 시각화하기 위해 Apotome 첨부 파일이 촬영됩니다. </li></ol> 5. Cryosectioning Cryosectioning는 세포 및 immunostaining에 대한 더 적용에 형광 단백질의 분포를 시각적으로 대안적인 방법입니다. 10 단계에서 배아는 덴트의 정착액 (20 % DMSO, 80 % 메탄올)와 1-2시간에 대한 해결되었습니다 PBS로 씻어하고, 15 % 생선 gelatin/15 %의 자당 솔루션 11 내장. 임베디드 배아는 빠르게 드라이 아이스에 냉동하고 cryosections는 Leica 그라 이오 스탯에 생성됩니다. 크로스 섹션 주입 RNAS 및 번역된 단백질 제품을 상속 ectodermal 세포를 포함합니다. 섹션 형광 보유 및 특정 항체와 immunostained 후 형광과 복합 보조 항체로 분류하실 수 있습니다. 핵은 DAPI 물들일 수 있습니다. 설치 미디어는 위에서 설명한 것과 동일합니다. 위에서 설명한 영상을 수행할 수 있습니다. 6. 대표 결과 : <img src="/files/ftp_upload/2700/2700fig1.jpg" alt="그림 1" /> 그림 1. Frizzled 수용체는 세포막에 Diversin을 모집. Frizzled 8 (Xfz8) 및 사업부 - RFP의 RNAS을 표현 Ectoderm 세포 대신의 세포막에서 사업부 - RFP를 공개 centrosome합니다 (G - tubulin의 공동 얼룩으로 나타났다). 실험의 계획은 상단에, 전형적인 단면이 표시됩니다.

<ol>
	<li>Gurdon, J. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Embryonic+induction+---+molecular+aspects.">Embryonic induction --- molecular aspects.</a> Development. 99, 285-306 (1987).</li><li>Moody, S. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Principles of Developmental Genetics. , (2007).</li><li>Clevers, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Wnt/beta-catenin+signaling+in+development+and+disease.">Wnt/beta-catenin signaling in development and disease.</a> Cell. 127, 469-480 (2006).</li><li>Klaus, A., Birchmeier, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Wnt+signalling+and+its+impact+on+development+and+cancer.">Wnt signalling and its impact on development and cancer.</a> Nat Rev Cancer. 8, 387-398 (2008).</li><li>Gordon, M. D., Nusse, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Wnt+signaling:+multiple+pathways,+multiple+receptors,+and+multiple+transcription+factors.">Wnt signaling: multiple pathways, multiple receptors, and multiple transcription factors.</a> J Biol Chem. 281, 22429-22433 (2006).</li><li>Schwarz-Romond, T., Asbrand, C., Bakkers, J., Kuhl, M., Schaeffer, H. J., Huelsken, J., Behrens, J., Hammerschmidt, M., Birchmeier, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+ankyrin+repeat+protein+Diversin+recruits+Casein+kinase+Iepsilon+to+the+beta-catenin+degradation+complex+and+acts+in+both+canonical+Wnt+and+Wnt/JNK+signaling.">The ankyrin repeat protein Diversin recruits Casein kinase Iepsilon to the beta-catenin degradation complex and acts in both canonical Wnt and Wnt/JNK signaling.</a> Genes Dev. 16, 2073-2084 (2002).</li><li>Moeller, H., Jenny, A., Schaeffer, H. J., Schwarz-Romond, T., Mlodzik, M., Hammerschmidt, M., Birchmeier, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diversin+regulates+heart+formation+and+gastrulation+movements+in+development.">Diversin regulates heart formation and gastrulation movements in development.</a> Proc Natl Acad Sci U S A. 103, 15900-15905 (2006).</li><li>Itoh, K., Jenny, A., Mlodzik, M., Sokol, S. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Centrosomal+localization+of+Diversin+and+its+relevance+to+Wnt+signaling.">Centrosomal localization of Diversin and its relevance to Wnt signaling.</a> J. Cell Sci. 122, 3791-3798 (2009).</li><li>Itoh, K., Jacob, J., Sokol, Y. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+role+for+Xenopus+Frizzled+8+in+dorsal+development.">A role for Xenopus Frizzled 8 in dorsal development.</a> Mech Dev. 74, 145-157 (1998).</li><li>Newport, J., Kirschner, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+major+developmental+transition+in+early+Xenopus+embryos:+I.+characterization+and+timing+of+cellular+changes+at+the+midblastula+stage.">A major developmental transition in early Xenopus embryos: I. characterization and timing of cellular changes at the midblastula stage.</a> Cell. 30, 675-686 (1982).</li><li>Itoh, K., Brott, B. K., Bae, G. U., Ratcliffe, M. J., Sokol, S. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nuclear+localization+is+required+for+Dishevelled+function+in+Wnt/beta-catenin+signaling.">Nuclear localization is required for Dishevelled function in Wnt/beta-catenin signaling.</a> J Biol. 4, 3-3 (2005).</li></ol>

관심 없음 충돌 선언하지 않습니다.

우리는 Diversin의 subcellular 지방화를 특징으로 위의 프로토콜을 사용하고 있습니다. 동물 극 explants에서 Diversin - RFP는 핵 옆에 발견되었으며 cryosections (그림 1)에서 G - tubulin, centrosomal 마커와 colocalized. 단백질의 subcellular 지방화가 확인되면, 삭제 구조는 단백질 도메인이 필요하고 subcellular 지방화 충분되는 구축 생성할 수 있습니다. 이 방법을 사용 Diversin의 centrosomal 현지화 도메인은 중간에 매핑되?...

polarized translocation of fluorescent proteins in xenopus ectoderm in response to wnt signaling

세포 극성 동적으로 배아 개발 1, 2 중 내장 및 외부 양쪽 요인에 의해 규제됩니다 진핵 세포의 기본 속성입니다. 이 규정에 관련된 신호 경로 중 하나는 embryogenesis 동안 여러 번 사용하고 인간의 질병에 3, 4, 5에 중요합니다 Wnt 경로입니다. 이 경로의 여러 분자 구성 요소는 coordinately 공간 제한 방식으로 신호를 통제하지만 기본 메커니즘은 완전히 이해되지 않습니다. Xenopus 배아 상피 세포가 다양한 신호 단백질의 subcellular 지방화를 공부하는 우수한 시스템입니다. 형광등 융합 단백질은 RNA의 microinjection에 의해 Xenopus의 배아에서 표현, ectodermal의 explants 준비하고 단백질 지방화는 epifluorescence에 의해 평가됩니다. 이 실험 프로토콜에서 우리는 Diversin, 신호 및 세포 극성 결정 6, 7에 연루되어 세포질 단백질의 subcellular 지방화는 Wnt 신호 전달 8 공부 Xenopus ectodermal 세포의 시각이다 방법에 대해 설명합니다. Wnt 리간드 또는 Frizzled 수용체의 Coexpression 붉은 형광 단백질, RFP와 함께 융합 Diversin의 유통을 바꿀지도 모르겠어, 그리고 편광 패션 8, 9에있는 세포막에 모집. 이 전 생체내 프로토콜은 신호의 공간적 제어 손상 조직과는 다른 그리고 더 많은 어려운 분석되는 교양 포유 동물 세포의 체외 연구에서에 대한 유용한 이외해야합니다.

Watch this Scientific Journal Video about Polarized Translocation of Fluorescent Proteins in Xenopus Ectoderm in Response to Wnt Signaling at JoVE.com

Polarized Translocation of Fluorescent Proteins in Xenopus Ectoderm in Response to Wnt Signaling

Xenopus ectoderm은 배아의 세포 극성의 연구에 대한 매력적인 모델이되고있다. 분석은 형광 단백질의 subcellular 배포는 ectoderm 세포에 과세되는, 설명되어 있습니다. 이 프로토콜은 신호의 공간적 제어 관련 주소 질문을하는 데 도움이됩니다.

의 형광 단백질의 편광 Translocation XenopusWnt 신호에 응답> Ectoderm

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

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Biology

Polarized Translocation of Fluorescent Proteins in Xenopus Ectoderm in Response to Wnt Signaling

10.7K 조회수.  Mount Sinai School of Medicine. Xenopus ectoderm은 배아의 세포 극성의 연구에 대한 매력적인 모델이되고있다. 분석은 형광 단백질의 subcellular 배포는 ectoderm 세포에 과세되는, 설명되어 있습니다. 이 프로토콜은 신호의 공간적 제어 관련 주소 질문을하는 데 도움이됩니다.

비디오: Polarized Translocation of Fluorescent Proteins in Xenopus Ectoderm in Response to Wnt Signaling

Quantification of &gamma;H2AX Foci in Response to Ionising Radiation

DNA double-strand breaks (DSBs), which are induced by either endogenous metabolic processes or by exogenous sources, are one of the most critical DNA lesions with respect to survival and preservation of genomic integrity. An early response to the induction of DSBs is phosphorylation of the H2A histone variant, H2AX, at the serine-139 residue, in the highly conserved C-terminal SQEY motif, forming &gamma;H2AX1. Following induction of DSBs, H2AX is rapidly phosphorylated by the phosphatidyl-inosito 3-kinase (PIKK) family of proteins, ataxia telangiectasia mutated (ATM), DNA-protein kinase catalytic subunit and ATM and RAD3-related (ATR)2. Typically, only a few base-pairs (bp) are implicated in a DSB, however, there is significant signal amplification, given the importance of chromatin modifications in DNA damage signalling and repair. Phosphorylation of H2AX mediated predominantly by ATM spreads to adjacent areas of chromatin, affecting approximately 0.03% of total cellular H2AX per DSB2,3. This corresponds to phosphorylation of approximately 2000 H2AX molecules spanning ~2 Mbp regions of chromatin surrounding the site of the DSB and results in the formation of discrete &gamma;H2AX foci which can be easily visualized and quantitated by immunofluorescence microscopy2. The loss of &gamma;H2AX at DSB reflects repair, however, there is some controversy as to what defines complete repair of DSBs; it has been proposed that rejoining of both strands of DNA is adequate however, it has also been suggested that re-instatement of the original chromatin state of compaction is necessary4-8. The disappearence of &gamma;H2AX involves at least in part, dephosphorylation by phosphatases, phosphatase 2A and phosphatase 4C5,6. Further, removal of &gamma;H2AX by redistribution involving histone exchange with H2A.Z has been implicated7,8. Importantly, the quantitative analysis of &gamma;H2AX foci has led to a wide range of applications in medical and nuclear research. Here, we demonstrate the most commonly used immunofluorescence method for evaluation of initial DNA damage by detection and quantitation of &gamma;H2AX foci in &gamma;-irradiated adherent human keratinocytes9.

Quantification of &amp;#947;H2AX Foci in Response to Ionising Radiation

Quantification of DNA double-strand streaks using &gamma;H2AX formation as a molecular marker has become an invaluable tool in radiation biology. Here we demonstrate the use of an immunofluorescence assay for quantification of &gamma;H2AX foci after exposure of cells to radiation.

Ionising 방사선에 대한 응답으로 γH2AX Foci의 부량

DNA double-strand breaks (DSBs), which are induced by either endogenous metabolic processes or by exogenous sources, are one of the most critical DNA ...

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생물학

Photoconversion of Purified Fluorescent Proteins and Dual-probe Optical Highlighting in Live Cells

Photoconvertible fluorescent proteins (pc-FPs) are a class of fluorescent proteins with "optical highlighter" capability, meaning that the color of fluorescence can be changed by exposure to light of a specific wavelength. Optical highlighting allows noninvasive marking of a subpopulation of fluorescent molecules, and is therefore ideal for tracking single cells or organelles.
Critical parameters for efficient photoconversion are the intensity and the exposure time of the photoconversion light. If the intensity is too low, photoconversion will be slow or not occur at all. On the other hand, too much intensity or too long exposure can photobleach the protein and thereby reduce the efficiency of photoconversion.
This protocol describes a general approach how to set up a confocal laser scanning microscope for pc-FP photoconversion applications. First, we describe a procedure for preparing purified protein droplet samples. This sample format is very convenient for studying the photophysical behavior of fluorescent proteins under the microscope. Second, we will use the protein droplet sample to show how to configure the microscope for photoconversion. And finally, we will show how to perform optical highlighting in live cells, including dual-probe optical highlighting with mOrange2 and Dronpa.

This protocol describes a general approach to perform photoconversion of fluorescent proteins on a confocal laser scanning microscope. We describe procedures for the photoconversion of puried protein samples, as well as for dual-probe optical highlighting in live cells with mOrange2 and Dronpa.

라이브 세포에 형광 단백질과 듀얼 프로브 광학 하이라이트 기능을 정화의 Photoconversion

Photoconvertible fluorescent proteins (pc-FPs) are a class of fluorescent proteins with "optical highlighter" capability, meaning that the color of ...

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 also be used to study the structure-function relationship for other ion channels and neurotransmitter receptors1. BK channels are widely expressed in different tissues and have been implicated in many physiological functions, including regulation of smooth muscle contraction, frequency tuning of inner hair cells and regulation of neurotransmitter release2-6. BK channels are activated by membrane depolarization and by intracellular Ca2+ and Mg2+ 6-9. Therefore, the protocol is designed to control both the membrane voltage and the intracellular solution. In this protocol, messenger RNA of BK channels is injected into Xenopus laevis oocytes (stage V-VI) followed by 2-5 days of incubation at 18&deg;C10-13. Membrane patches that contain single or multiple BK channels are excised with the inside-out configuration using patch clamp techniques10-13. The intracellular side of the patch is perfused with desired solutions during recording so that the channel activation under different conditions can be examined. To summarize, the mRNA of BK channels is injected into Xenopus laevis oocytes to express channel proteins on the oocyte membrane; patch clamp techniques are used to record currents flowing through the channels under controlled voltage and intracellular solutions.

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

Ionic current of BK channels is recorded using patch clamp techniques. BK channels are expressed in Xenopus oocytes by injecting messenger RNA. The intracellular solution during patch clamp recordings is controlled by a perfusion system.

이온 채널 유학을위한 패치 클램프 및 재관류 기법으로 표현 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 ...

Rapid Genetic Analysis of Epithelial-Mesenchymal Signaling During Hair Regeneration

Hair follicle morphogenesis, a complex process requiring interaction between epithelia-derived keratinocytes and the underlying mesenchyme, is an attractive model system to study organ development and tissue-specific signaling. Although hair follicle development is genetically tractable, fast and reproducible analysis of factors essential for this process remains a challenge. Here we describe a procedure to generate targeted overexpression or shRNA-mediated knockdown of factors using lentivirus in a tissue-specific manner. Using a modified version of a hair regeneration model 5, 6, 11, we can achieve robust gain- or loss-of-function analysis in primary mouse keratinocytes or dermal cells to facilitate study of epithelial-mesenchymal signaling pathways that lead to hair follicle morphogenesis. We describe how to isolate fresh primary mouse keratinocytes and dermal cells, which contain dermal papilla cells and their precursors, deliver lentivirus containing either shRNA or cDNA to one of the cell populations, and combine the cells to generate fully formed hair follicles on the backs of nude mice. This approach allows analysis of tissue-specific factors required to generate hair follicles within three weeks and provides a fast and convenient companion to existing genetic models.

Tissue-specific analysis of a hair follicle regeneration model using lentivirus to mediate gain- or loss-of-function.

헤어 재생시 상피 - 중간 엽 시그널링의 빠른 유전 분석

Hair follicle morphogenesis, a complex process requiring interaction between epithelia-derived keratinocytes and the underlying mesenchyme, is an ...

Intravital Microscopy for Imaging Subcellular Structures in Live Mice Expressing Fluorescent Proteins

Here we describe a procedure to image subcellular structures in live rodents that is based on the use of confocal intravital microscopy. As a model organ, we use the salivary glands of live mice since they provide several advantages. First, they can be easily exposed to enable access to the optics, and stabilized to facilitate the reduction of the motion artifacts due to heartbeat and respiration. This significantly facilitates imaging and tracking small subcellular structures. Second, most of the cell populations of the salivary glands are accessible from the surface of the organ. This permits the use of confocal microscopy that has a higher spatial resolution than other techniques that have been used for in vivo imaging, such as two-photon microscopy. Finally, salivary glands can be easily manipulated pharmacologically and genetically, thus providing a robust system to investigate biological processes at a molecular level.
In this study we focus on a protocol designed to follow the kinetics of the exocytosis of secretory granules in acinar cells and the dynamics of the apical plasma membrane where the secretory granules fuse upon stimulation of the beta-adrenergic receptors. Specifically, we used a transgenic mouse that co-expresses cytosolic GFP and a membrane-targeted peptide fused with the fluorescent protein tandem-Tomato. However, the procedures that we used to stabilize and image the salivary glands can be extended to other mouse models and coupled to other approaches to label in vivo cellular components, enabling the visualization of various subcellular structures, such as endosomes, lysosomes, mitochondria, and the actin cytoskeleton.

Intravital microscopy is a powerful tool that enables imaging various biological processes in live animals. In this article, we present a detailed method for imaging the dynamics of subcellular structures, such as the secretory granules, in the salivary glands of live mice.

형광 단백질을 표현 라이브 마우스의 이미징 세포 이하의 구조물의 intravital 현미경

Here we describe a procedure to image subcellular structures in live rodents that is based on the use of confocal intravital microscopy. As a model organ, ...

Facial Transplants in Xenopus laevis Embryos

Craniofacial birth defects occur in 1 out of every 700 live births, but etiology is rarely known due to limited understanding of craniofacial development. To identify where signaling pathways and tissues act during patterning of the developing face, a 'face transplant' technique has been developed in embryos of the frog Xenopus laevis. A region of presumptive facial tissue (the "Extreme Anterior Domain" (EAD)) is removed from a donor embryo at tailbud stage, and transplanted to a host embryo of the same stage, from which the equivalent region has been removed. This can be used to generate a chimeric face where the host or donor tissue has a loss or gain of function in a gene, and/or includes a lineage label. After healing, the outcome of development is monitored, and indicates roles of the signaling pathway within the donor or surrounding host tissues. Xenopus is a valuable model for face development, as the facial region is large and readily accessible for micromanipulation. Many embryos can be assayed, over a short time period since development occurs rapidly. Findings in the frog are relevant to human development, since craniofacial processes appear conserved between Xenopus and mammals.

Facial Transplants in Xenopus laevis Embryos

A technique for transplanting "Extreme Anterior Domain" facial tissue between Xenopus laevis embryos has been developed. Tissue can be moved from one gene expression background into another, allowing the study of local requirements for craniofacial development and for signaling interactions between facial regions.

의 얼굴 이식<em&gt;는 Xenopus laevis의</em&gt; 태아

Craniofacial birth defects occur in 1 out of every 700 live births, but etiology is rarely known due to limited understanding of craniofacial development. ...

The Xenopus Oocyte Cut-open Vaseline Gap Voltage-clamp Technique With Fluorometry

The cut-open oocyte Vaseline gap (COVG) voltage clamp technique allows for analysis of electrophysiological and kinetic properties of heterologous ion channels in oocytes. Recordings from the cut-open setup are particularly useful for resolving low magnitude gating currents, rapid ionic current activation, and deactivation. The main benefits over the two-electrode voltage clamp (TEVC) technique include increased clamp speed, improved signal-to-noise ratio, and the ability to modulate the intracellular and extracellular milieu.
Here, we employ the human cardiac sodium channel (hNaV1.5), expressed in Xenopus oocytes, to demonstrate the cut-open setup and protocol as well as modifications that are required to add voltage clamp fluorometry capability.
The properties of fast activating ion channels, such as hNaV1.5, cannot be fully resolved near room temperature using TEVC, in which the entirety of the oocyte membrane is clamped, making voltage control difficult. However, in the cut-open technique, isolation of only a small portion of the cell membrane allows for the rapid clamping required to accurately record fast kinetics while preventing channel run-down associated with patch clamp techniques.
In conjunction with the COVG technique, ion channel kinetics and electrophysiological properties can be further assayed by using voltage clamp fluorometry, where protein motion is tracked via cysteine conjugation of extracellularly applied fluorophores, insertion of genetically encoded fluorescent proteins, or the incorporation of unnatural amino acids into the region of interest1. This additional data yields kinetic information about voltage-dependent conformational rearrangements of the protein via changes in the microenvironment surrounding the fluorescent molecule.

The Xenopus Oocyte Cut-open Vaseline Gap Voltage-clamp Technique With Fluorometry

The cut-open Vaseline gap approach is used to obtain low noise recordings of ionic and gating currents from voltage-dependent ion channels expressed in Xenopus oocytes with high resolution of fast channel kinetics. With minor modification, voltage clamp fluorometry can be coupled to the cut-open oocyte protocol.

<em&gt; Xenopus의</em형광 측정으로&gt; 난자 절개 바셀린 갭 전압 클램프 기술

The cut-open oocyte Vaseline gap (COVG) voltage clamp technique allows for analysis of electrophysiological and kinetic properties of heterologous ion ...

Reconstitution Of &#946;-catenin Degradation In Xenopus Egg Extract

Xenopus laevis egg extract is a well-characterized, robust system for studying the biochemistry of diverse cellular processes. Xenopus egg extract has been used to study protein turnover in many cellular contexts, including the cell cycle and signal transduction pathways1-3. Herein, a method is described for isolating Xenopus egg extract that has been optimized to promote the degradation of the critical Wnt pathway component, &beta;-catenin. Two different methods are described to assess &beta;-catenin protein degradation in Xenopus egg extract. One method is visually informative ([35S]-radiolabeled proteins), while the other is more readily scaled for high-throughput assays (firefly luciferase-tagged fusion proteins). The techniques described can be used to, but are not limited to, assess &beta;-catenin protein turnover and identify molecular components contributing to its turnover. Additionally, the ability to purify large volumes of homogenous Xenopus egg extract combined with the quantitative and facile readout of luciferase-tagged proteins allows this system to be easily adapted for high-throughput screening for modulators of &beta;-catenin degradation.

Reconstitution Of &amp;#946;-catenin Degradation In Xenopus Egg Extract

A method is described for analyzing protein degradation using radiolabeled and luciferase-fusion proteins in Xenopus egg extract and its adaptation for high-throughput screening for small molecule modulators of protein degradation.

β-catenin의 저하의 재구성<em&gt; Xenopus의</em&gt; 계란 추출

Xenopus laevis egg extract is a well-characterized, robust system for studying the biochemistry of diverse cellular processes. Xenopus egg extract has ...

Quantification of Orofacial Phenotypes in Xenopus

Xenopus has become an important tool for dissecting the mechanisms governing craniofacial development and defects. A method to quantify orofacial development will allow for more rigorous analysis of orofacial phenotypes upon abrogation with substances that can genetically or molecularly manipulate gene expression or protein function. Using two dimensional images of the embryonic heads, traditional size dimensions-such as orofacial width, height and area- are measured. In addition, a roundness measure of the embryonic mouth opening is used to describe the shape of the mouth. Geometric morphometrics of these two dimensional images is also performed to provide a more sophisticated view of changes in the shape of the orofacial region. Landmarks are assigned to specific points in the orofacial region and coordinates are created. A principle component analysis is used to reduce landmark coordinates to principle components that then discriminate the treatment groups. These results are displayed as a scatter plot in which individuals with similar orofacial shapes cluster together. It is also useful to perform a discriminant function analysis, which statistically compares the positions of the landmarks between two treatment groups. This analysis is displayed on a transformation grid where changes in landmark position are viewed as vectors. A grid is superimposed on these vectors so that a warping pattern is displayed to show where significant landmark positions have changed. Shape changes in the discriminant function analysis are based on a statistical measure, and therefore can be evaluated by a p-value. This analysis is simple and accessible, requiring only a stereoscope and freeware software, and thus will be a valuable research and teaching resource.

Quantification of Orofacial Phenotypes in Xenopus

A method to quantify the orofacial size and shape of Xenopus laevis embryos has been developed. In this protocol, traditional size measurements are combined with geometric morphometrics to allow for more sophisticated analyses of orofacial development and defects.

구강 안면 표현형의 정량화에<em&gt; Xenopus의</em

Xenopus has become an important tool for dissecting the mechanisms governing craniofacial development and defects. A method to quantify orofacial ...

Measuring Glutathione-induced Feeding Response in Hydra

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

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

히드라의 글루타티온 유도 먹이 반응을 측정

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