这项工作得到了 NIH DK092408 和 DK100227 对生产商的支持. AJR 得到了 T32-DK007013 的支持。作者希望感谢 Dr. 科尔尼 CapaR-GAL4 和 c724-GAL4 的果蝇股票。我们还感谢雅各布 b. 安德森协助维持实验飞行十字架。

作者没有什么可透露的。

在果蝇mts 中, pH 值i的量化成功与否完全取决于提取的 mts 的运行状况以及安装和剥离的质量 (图 A - C)。因此, 仔细处理组织的描述是势在必行的。新涂在 PLL 上的幻灯片实质上有助于 MT 的安装, 因为它们比以前暴露在溶液中的幻灯片更容易粘合。小心安装也有助于识别不同的 MT 段 (图 D)。健康 MTs 分别通过减少 mCherry 聚合和产生更?...

本议定书的目的是用基因编码的 ph 指示剂 (GEpHI) 描述细胞内 ph 值 (ph 值i) 的量化, 并演示这种方法如何用于评估模型昆虫中的侧 H+传输 (D。腹氏管 (MT) 的肾脏结构。MTs 作为果蝇的排泄器官, 在几个关键方面与哺乳动物肾单位的功能相似,1。在苍蝇的胸腔和腹部, MTs 排列为2对小管 (前后)。每个 MT 的单细胞上皮管由新陈代谢活性主细胞组成, 具有明显的顶端 (腔) 和侧 (腔) 极性, 以及夹层星状细胞。前 MTs 由3形态、功能和发育的不同部分组成, 特别是最初的扩张段、移行段和分泌主段, 它们连接到输尿管的2。在细胞尺度的跨上皮离子传输到流明是由一个顶端的等离子膜 V atp 酶3和一个碱金属/H+换热器以及一个侧 Na+-K-atp 酶4,内整流 K+通道5, Na+驱动 Cl−/小贩3−交换器 (NDAE1)6和 Na+-K+2Cl− cotransporter (NKCC;Ncc69)7, 而星状细胞介导 Cl-和水传输8,9。这一复杂但容易接近的生理系统提供了极好的机会, 研究内源性离子转运机制时, 结合了不同的遗传和行为工具的果蝇。
这个协议的基本原理是描述一个遗传可塑性的系统研究上皮离子运输有潜在的集成从细胞到行为和出口的工具到其他模型系统。pHerry10的表达式, GEpHI 从绿色 ph 值敏感的 super-ecliptic pHluorin11、12 (SEpH) 和红色 ph 不敏感的 mCherry13的融合中派生而来, 在 MTs 中允许量化 H+传输单 MT 细胞通过高 K+/尼日利亚校准技术14。由于许多离子转运体移动了 H+当量, 细胞内 pH 值i的量化是通过各种转运体的离子运动的功能表征。果蝇MT 模型系统还提供了功能强大的基因工具在组织特异转基因15和 rna 干涉 (干扰)16表达式, 可以结合细胞成像和全身检测17,18,19的小管函数创建一个具有从分子到行为的垂直集成的健壮工具集。这与许多其他用于评估上皮生物学的协议相对照, 因为历史上这种测量依赖于复杂而艰巨的微解剖, 尖端的离子选择性电极20,21,和昂贵的 pH 敏感染料22 , 具有限制性的负载要求和不均匀组织中的细胞特异性差。GEpHIs 已被用来广泛测量 pHi在各种细胞类型23。早期工作利用绿色荧光蛋白 (GFP) 的固有 ph 敏感度来监测培养的上皮细胞中的 ph 值i 24但过去20年中, 在神经元中使用过 GEpHIs25、胶质26、真菌27和植物细胞28。通过 GAL4/UAS 表达系统15和果蝇MT 的生理可访问性, 将基因构造的细胞靶向性结合起来, 使之成为研究 pH 值的理想准备.调节和上皮离子转运。
pH 值i规则已进行了几十年的研究, 对生命至关重要。MT 制剂提供了一个健壮的模型来教授生理学的 ph 值i调节, 但也执行复杂的研究 ph 值i调节ex 体内和体内。本协议描述了使用 NH4Cl 脉冲酸加载技术21, 在果蝇MT 的上皮细胞的侧膜上进行 H+运动的量化, 但由于 pH 值是基因编码, 这些方法和他们的理论框架可以适用于任何准备转基因和活成像。

<table>
	<tbody>
		<tr>
			<td>Poly-L-Lysine Solution</td>
			<td>Sigma-Aldrich</td>
			<td>P4832</td>
			<td>Store at 4 &#176;C, can be reused.</td>
		</tr>
		<tr>
			<td>Nigericin Sodium Salt</td>
			<td>Sigma-Aldrich</td>
			<td>N7143</td>
			<td>CAUTION: Handle with gloves. Store as aliquots of 20 mM stock solution in DMSO at 4 &#176;C.</td>
		</tr>
		<tr>
			<td>Adhesive Perfusion Chamber Covers, adhesive size 1 mm, chamber diameter &#215; thickness 9 mm &#215; 0.9 mm, ports diameter 1.5 mm</td>
			<td>Sigma-Aldrich</td>
			<td>GBL622105</td>
			<td>Can be substituted as needed to match perfusion system.</td>
		</tr>
		<tr>
			<td>Sylgard 184 Silicone Elastomer Kit</td>
			<td>Ellsworth Adhesives</td>
			<td>184 SIL ELAST KIT 0.5KG</td>
			<td>Available from multiple vendors.</td>
		</tr>
		<tr>
			<td>Helping Hands Soldering Stands</td>
			<td>Harbor Freight Tools</td>
			<td>60501</td>
			<td>Available from multiple vendors.</td>
		</tr>
		<tr>
			<td>Open Gravity-fed Perfusion System with Valve Controller, 8 to 1 Manifold and Reserviors</td>
			<td>Bioscience Tools</td>
			<td>PS-8S</td>
			<td>Any comparable perfusion system can be used.</td>
		</tr>
		<tr>
			<td>Flow Regulator</td>
			<td>Warner Instruments</td>
			<td>64-0221</td>
			<td>Can be substituted as needed to match perfusion system.</td>
		</tr>
		<tr>
			<td>Schneider&#39;s Medium</td>
			<td>Fisher Scientific</td>
			<td>21720024</td>
			<td>Store at 4 &#176;C in sterile aliquots.</td>
		</tr>
		<tr>
			<td>#5 Inox Steel Forceps</td>
			<td>Fine Science Tools</td>
			<td>11252-20</td>
			<td>Can be substituted based on experimenter comfort.</td>
		</tr>
		<tr>
			<td>35 mm x 10 mm polystyrene Petri dish</td>
			<td>Corning Life Sciences</td>
			<td>Fisher Scientific 08-757-100A</td>
			<td>Exact brand and size are unimportant.</td>
		</tr>
		<tr>
			<td>75 x 25 mm Microscope Slides</td>
			<td>Corning Life Sciences</td>
			<td>2949-75X25</td>
			<td>Exact brand and size can vary as long as perfusion wells are compatible.</td>
		</tr>
		<tr>
			<td>Filimented Borosilicate Capillary Glass, ID 1.5 mm, OD 0.86 mm, thickness 0.32 mm</td>
			<td>Warner Instruments</td>
			<td>64-0796</td>
			<td>Filiment not necessary, glass can be substituted to match perfusion tubing and perfusion wells.</td>
		</tr>
		<tr>
			<td>Tygon Tubing, ID 1/16 inch, OD 1/8 inch, thickness 1/32 inch</td>
			<td>Fisher Scientific</td>
			<td>14-171-129</td>
			<td>Available from multiple vendors, can be substituted to match perfusion system.</td>
		</tr>
		<tr>
			<td>Vacuum Silicone Grease</td>
			<td>Sigma-Aldrich</td>
			<td>Z273554</td>
			<td>Available from multiple vendors.</td>
		</tr>
		<tr>
			<td>Plastic Flow Control Clamp</td>
			<td>Fisher Scientific</td>
			<td>05-869</td>
			<td>Available from multiple vendors, sterility not required</td>
		</tr>
		<tr>
			<td>Glass rods, 5 mm diameter</td>
			<td>delphiglass.com</td>
			<td>9198</td>
			<td>Exact size is personal preference, multiple vendors available</td>
		</tr>
		<tr>
			<td>PAP Hydrophobic Pen</td>
			<td>Sigma-Aldrich</td>
			<td>Z377821</td>
			<td>Available from multiple vendors.</td>
		</tr>
		<tr>
			<td>Sealing Film</td>
			<td>Sigma-Aldrich</td>
			<td>P7668</td>
			<td>Available from multiple vendors.</td>
		</tr>
		<tr>
			<td>15 mL Falcon tube</td>
			<td>BD Falcon</td>
			<td>352096</td>
			<td>Available from multiple vendors.</td>
		</tr>
		<tr>
			<td>50 mL Falcon tube</td>
			<td>BD Falcon</td>
			<td>352070</td>
			<td>Available from multiple vendors.</td>
		</tr>
		<tr>
			<td>HEPES; 4-(2-Hydroxyethyl)piperazine-1-ethanesulfonic acid</td>
			<td>Sigma-Aldrich</td>
			<td>H3375</td>
			<td>Available from multiple vendors.</td>
		</tr>
		<tr>
			<td>MES; 4-Morpholineethanesulfonic acid monohydrate</td>
			<td>Sigma-Aldrich</td>
			<td>69892</td>
			<td>Available from multiple vendors.</td>
		</tr>
		<tr>
			<td>TAPS; N-[Tris(hydroxymethyl)methyl]-3-aminopropanesulfonic acid</td>
			<td>Sigma-Aldrich</td>
			<td>T5130</td>
			<td>Available from multiple vendors.</td>
		</tr>
		<tr>
			<td>10x/0.45 Air Objective</td>
			<td>Zeiss</td>
			<td>000000-1063-139</td>
			<td>Comparable objectives can be substituted. 40x objectives can be used for single cell imaging.</td>
		</tr>
		<tr>
			<td>Dissecting Stereoscope</td>
			<td>Zeiss</td>
			<td>Discovery.V8</td>
			<td>Any dissecting stereoscope can be used.</td>
		</tr>
		<tr>
			<td>UAS-pHerry transgenic Drosophila melagnogaster</td>
			<td>Available from Romero Lab</td>
			<td></td>
			<td>First published: Citation 10</td>
		</tr>
		<tr>
			<td>capaR-GAL4 driver line Drosophila melagnogaster</td>
			<td>Available from Romero Lab</td>
			<td></td>
			<td>First published: Citation 32</td>
		</tr>
		<tr>
			<td>c724-GAL4 driver line Drosophila melagnogaster</td>
			<td>Available from Romero Lab</td>
			<td></td>
			<td>First published: Citation 2</td>
		</tr>
		<tr>
			<td>Monochromatic High Sensitivity Digital Camera</td>
			<td>Zeiss</td>
			<td>Axiocam 506 mono</td>
			<td>Exact brand and model can vary, can be replaced with any monochromatic high-sensitivity camera suited to live cellular imaging.</td>
		</tr>
		<tr>
			<td>GFP/FITC filter set, 470/40 nm ex., 515 nm longpass em., 500 nm dichroic</td>
			<td>Chroma</td>
			<td>CZ909</td>
			<td>Any GFP/FITC filer set can be substituted.</td>
		</tr>
		<tr>
			<td>RFP/TRITC filter set, 546/10 nm ex., 590 nm longpass em., 565 nm dichroic</td>
			<td>Chroma</td>
			<td>CZ915</td>
			<td>Any GFP/FITC filer set can be substituted.</td>
		</tr>
		<tr>
			<td>Inverted Epifluoescent Microscope</td>
			<td>Zeiss</td>
			<td>Axio Observer Z.1</td>
			<td>Any comparable microscope with motorized filter switching can be used. Upright microscopes can be used with open perfusion baths and water-immersion objectives.</td>
		</tr>
		<tr>
			<td>Statistical Analysis Software</td>
			<td>Microcal</td>
			<td>Origin 6.0</td>
			<td>Any software with comparable functionality can be substituted</td>
		</tr>
		<tr>
			<td>Image Analysis Software</td>
			<td>National Institutes of Health</td>
			<td>ImageJ 1.50i</td>
			<td>Any software with comparable functionality can be substituted</td>
		</tr>
		<tr>
			<td>Image Acquisition Software</td>
			<td>Zeiss</td>
			<td>Zen 1.1.2.0</td>
			<td>Any software with comparable functionality can be substituted</td>
		</tr>
		<tr>
			<td>Single-edged Carbon Steel Razor Blade</td>
			<td>Electron Microscopy Sciences</td>
			<td>71960</td>
			<td>Available from multiple vendors.</td>
		</tr>
		<tr>
			<td>Microscopy Slide Folder</td>
			<td>Fisher Scientific</td>
			<td>16-04</td>
			<td>Available from multiple vendors.</td>
		</tr>
		<tr>
			<td>Bunsen Burner</td>
			<td>Fisher Scientific</td>
			<td>50-110-1231</td>
			<td>Available from multiple vendors.</td>
		</tr>
		<tr>
			<td>Polystrene Drosophila Rearing Vials with Flugs</td>
			<td>Genesee Scientific</td>
			<td>32-109BF</td>
			<td>Comparable items can be substituted.</td>
		</tr>
		<tr>
			<td>2.5 L Laboratory Ice Bucket</td>
			<td>Fisher Scientific</td>
			<td>07-210-129</td>
			<td>Available from multiple vendors.</td>
		</tr>
		<tr>
			<td>NMDG; N-Methyl-D-glucamine</td>
			<td>Sigma-Aldrich</td>
			<td>M2004</td>
			<td>Available from multiple vendors.</td>
		</tr>
		<tr>
			<td>200 uL barrier pipette tips</td>
			<td>MidSci</td>
			<td>AV200</td>
			<td>Available from multiple vendors.</td>
		</tr>
		<tr>
			<td>200 uL variable volume pipette</td>
			<td>Gilson Incorporated</td>
			<td>PIPETMAN P200</td>
			<td>Available from multiple vendors.</td>
		</tr>
	</tbody>
</table>

optical quantification of intracellular ph in drosophila melanogaster malpighian tubule epithelia with a fluorescent genetically-encoded ph indicator

上皮离子转运对系统离子稳态和基本细胞电化学梯度的维持至关重要。细胞内 ph 值 (ph 值i) 受许多离子转运体的影响, 因此监测 ph 值i是评估转运体活动的有用工具。现代基因编码的 ph 指标 (GEpHIs) 提供了在细胞和亚细胞尺度上的完整单元的 ph 值i的光学定量。本议定书描述 real-time 定量的细胞 pHi调节在氏管 (MTs) 的果蝇通过ex 活体成像 pHerry, pseudo-ratiometric GEpHI 与 pK非常适合跟踪胞中的 pH 值变化。提取的成人蝇 MTs 是由形态和功能分明的单细胞层上皮的部分组成, 并可作为一个容易接近的和基因驯服的研究上皮运输模型。GEpHIs 提供了一些优于传统 pH 敏感荧光染料和离子选择电极的优势。GEpHIs 可以标记不同的细胞数量提供适当的启动子元素可用。此标记在ex 体内、体内和原位准备工作中特别有用, 它们本质上是异构的。GEpHIs 也允许定量的 pH 值i在完整的组织, 而无需重复染料治疗或组织外化。当前 GEpHIs 的主要缺点是在组织损伤和构造表达的反应中, 聚集在胞浆包裹体中的倾向。这些缺点, 它们的解决方案, 和 GEpHIs 的内在优势, 通过评估侧质子 (H) 在功能分明的主要和星状细胞中提取的飞行 MTs 的传输来证明.所描述的技术和分析可以很容易地适应各种各样的脊椎动物和无脊椎动物的准备工作, 而且化验的复杂程度可从教学实验室扩展到通过特定转运体对离子通量的复杂测定。

健康的组织和正确的识别前 MTs 是至关重要的成功的协议。在解剖过程中, 应注意不要直接接触 mts, 而只能由输尿管来处理, 因为握住 mts 直接会导致破损 (图 4A- B)。当 MTs 被平扫到滑梯上时, 小管必须尽可能少地接触, 避免多余的运动, 因为这会损害单细胞上皮层 (图 4C)。正确解剖前 MTs, 通过胞上皮细胞?...

Watch this Scientific Journal Video about Optical Quantification of Intracellular pH in Drosophila melanogaster Malpighian Tubule Epithelia with a Fluorescent Genetically-encoded pH Indicator at JoVE.

Optical Quantification of Intracellular pH in Drosophila melanogaster Malpighian Tubule Epithelia with a Fluorescent Genetically-encoded pH Indicator

细胞离子传输通常可以通过监测细胞内 ph 值(ph 值i)来评估。基因编码的 ph 值指标(GEpHIs)提供了细胞内 ph 值的光学定量。本议定书详细介绍了细胞内 ph 值的量化, 通过蜂窝状的前体活成像的氏管的果蝇与 pHerry, pseudo-ratiometric 基因编码的 pH 指标。

用荧光基因编码的 ph 指示剂对果蝇氏小管上皮细胞内 ph 值的光学定量

Epithelial ion transport is vital to systemic ion homeostasis as well as maintenance of essential cellular electrochemical gradients. Intracellular pH ...

optical-quantification-intracellular-ph-drosophila-melanogaster

Research

JoVE Journal

Biology

Optical Quantification of Intracellular pH in Drosophila melanogaster Malpighian Tubule Epithelia with a Fluorescent Genetically-encoded pH Indicator

10.1K 次观看.  Mayo Clinic College of Medicine. 细胞离子传输通常可以通过监测细胞内 ph 值(ph 值i)来评估。基因编码的 ph 值指标(GEpHIs)提供了细胞内 ph 值的光学定量。本议定书详细介绍了细胞内 ph 值的量化, 通过蜂窝状的前体活成像的氏管的果蝇与 pHerry, pseudo-ratiometric 基因编码的 pH 指标。

视频: Optical Quantification of Intracellular pH in Drosophila melanogaster Malpighian Tubule Epithelia with a Fluorescent Genetically-encoded pH Indicator

Dissection of Larval CNS in Drosophila Melanogaster

The central nervous system (CNS) of Drosophila larvae is complex and poorly understood.  One way to investigate the CNS is to use immunohistochemistry to examine the expression of various novel and marker proteins.  Staining of whole larvae is impractical because the tough cuticle prevents antibodies from penetrating inside the body cavity.  In order to stain these tissues it is necessary to dissect the animal prior to fixing and staining.  In this article we demonstrate how to dissect Drosophila larvae without damaging the CNS.  Begin by tearing the larva in half with a pair of fine forceps, and then turn the cuticle "inside-out" to expose the CNS.  If the dissection is performed carefully the CNS will remain attached to the cuticle.  We usually keep the CNS attached to the cuticle throughout the fixation and staining steps, and only completely remove the CNS from the cuticle just prior to mounting the samples on glass slides.  We also show some representative images of a larval CNS stained with Eve, a transcription factor expressed in a subset of neurons in the CNS.  The article concludes with a discussion of some of the practical uses of this technique and the potential difficulties that may arise.

In this article we demonstrate how to dissect the central nervous system from third instar Drosophila larvae.

在果蝇幼虫中枢神经系统的剖析

The central nervous system (CNS) of Drosophila larvae is complex and poorly understood.  One way to investigate the CNS is to use immunohistochemistry to ...

科研

生物学

Monitoring Heart Function in Larval Drosophila melanogaster for Physiological Studies

We present various methods to record cardiac function in the larval Drosophila. The approaches allow heart rate to be measured in unrestrained and restrained whole larvae. For direct control of the environment around the heart another approach utilizes the dissected larvae and removal of the internal organs in order to bathe the heart in desired compounds. The exposed heart also allows membrane potentials to be monitored which can give insight of the ionic currents generated by the myocytes and for electrical conduction along the heart tube. These approaches have various advantages and disadvantages for future experiments that are discussed. The larval heart preparation provides an additional model besides the Drosophila skeletal NMJ to investigate the role of intracellular calcium regulation on cellular function. Learning more about the underlying ionic currents that shape the action potentials in myocytes in various species, one can hope to get a handle on the known ionic dysfunctions associated to specific genes responsible for various diseases in mammals.

Monitoring Heart Function in Larval Drosophila melanogaster for Physiological Studies

We present various ways to monitor heart function in the larva of Drosophila for assessing questions dealing with the function of gap junctions, ion channel mutations, modulation of pacemaker activity and pharmacological studies.

在幼虫的监测心脏功能果蝇生理研究

We present various methods to record cardiac function in the larval Drosophila. The approaches allow heart rate to be measured in unrestrained  and  ...

Monitoring Dynamic Changes In Mitochondrial Calcium Levels During Apoptosis Using A Genetically Encoded Calcium Sensor

Dynamic changes in intracellular calcium concentration in response to various stimuli regulates many cellular processes such as proliferation, differentiation, and apoptosis1. During apoptosis, calcium accumulation in mitochondria promotes the release of pro-apoptotic factors from the mitochondria into the cytosol2. It is therefore of interest to directly measure mitochondrial calcium in living cells in situ during apoptosis. High-resolution fluorescent imaging of cells loaded with dual-excitation ratiometric and non-ratiometric synthetic calcium indicator dyes has been proven to be a reliable and versatile tool to study various aspects of intracellular calcium signaling. Measuring cytosolic calcium fluxes using these techniques is relatively straightforward. However, measuring intramitochondrial calcium levels in intact cells using synthetic calcium indicators such as rhod-2 and rhod-FF is more challenging. Synthetic indicators targeted to mitochondria have blunted responses to repetitive increases in mitochondrial calcium, and disrupt mitochondrial morphology3. Additionally, synthetic indicators tend to leak out of mitochondria over several hours which makes them unsuitable for long-term experiments. Thus, genetically encoded calcium indicators based upon green fluorescent protein (GFP)4 or aequorin5 targeted to mitochondria have greatly facilitated measurement of mitochondrial calcium dynamics. Here, we describe a simple method for real-time measurement of mitochondrial calcium fluxes in response to different stimuli. The method is based on fluorescence microscopy of 'ratiometric-pericam' which is selectively targeted to mitochondria. Ratiometric pericam is a calcium indicator based on a fusion of circularly permuted yellow fluorescent protein and calmodulin4. Binding of calcium to ratiometric pericam causes a shift of its excitation peak from 415 nm to 494 nm, while the emission spectrum, which peaks around 515 nm, remains unchanged. Ratiometric pericam binds a single calcium ion with a dissociation constant in vitro of ~1.7 &mu;M4. These properties of ratiometric pericam allow the quantification of rapid and long-term changes in mitochondrial calcium concentration. Furthermore, we describe adaptation of this methodology to a standard wide-field calcium imaging microscope with commonly available filter sets. Using two distinct agonists, the purinergic agonist ATP and apoptosis-inducing drug staurosporine, we demonstrate that this method is appropriate for monitoring changes in mitochondrial calcium concentration with a temporal resolution of seconds to hours. Furthermore, we also demonstrate that ratiometric pericam is also useful for measuring mitochondrial fission/fragmentation during apoptosis. Thus, ratiometric pericam is particularly well suited for continuous long-term measurement of mitochondrial calcium dynamics during apoptosis.

This protocol describes a method for real-time measurement of mitochondrial calcium fluxes by fluorescent imaging. The method takes advantage of a circularly permutated YFP-based dual-excitation ratiometric calcium sensor (ratiometric pericam-mt) selectively expressed in mitochondria.

使用一种基因编码的钙传感器来监测细胞凋亡过程中线粒体钙水平的动态变化

Dynamic changes in intracellular calcium concentration in response to various stimuli regulates many cellular processes such as proliferation, ...

Measurement of Lifespan in Drosophila melanogaster

Aging is a phenomenon that results in steady physiological deterioration in nearly all organisms in which it has been examined, leading to reduced physical performance and increased risk of disease. Individual aging is manifest at the population level as an increase in age-dependent mortality, which is often measured in the laboratory by observing lifespan in large cohorts of age-matched individuals. Experiments that seek to quantify the extent to which genetic or environmental manipulations impact lifespan in simple model organisms have been remarkably successful for understanding the aspects of aging that are conserved across taxa and for inspiring new strategies for extending lifespan and preventing age-associated disease in mammals.
The vinegar fly, Drosophila melanogaster, is an attractive model organism for studying the mechanisms of aging due to its relatively short lifespan, convenient husbandry, and facile genetics. However, demographic measures of aging, including age-specific survival and mortality, are extraordinarily susceptible to even minor variations in experimental design and environment, and the maintenance of strict laboratory practices for the duration of aging experiments is required. These considerations, together with the need to practice careful control of genetic background, are essential for generating robust measurements. Indeed, there are many notable controversies surrounding inference from longevity experiments in yeast, worms, flies and mice that have been traced to environmental or genetic artifacts1-4. In this protocol, we describe a set of procedures that have been optimized over many years of measuring longevity in Drosophila using laboratory vials. We also describe the use of the dLife software, which was developed by our laboratory and is available for download (<a href="http://sitemaker.umich.edu/pletcherlab/software">http://sitemaker.umich.edu/pletcherlab/software</a>). dLife accelerates throughput and promotes good practices by incorporating optimal experimental design, simplifying fly handling and data collection, and standardizing data analysis. We will also discuss the many potential pitfalls in the design, collection, and interpretation of lifespan data, and we provide steps to avoid these dangers.

Measurement of Lifespan in Drosophila melanogaster

Drosophila melanogaster is a powerful model organism for exploring the molecular basis of longevity regulation. This protocol will discuss the steps involved in generating a reproducible, population-based measurement of longevity as well as potential pitfalls and how to avoid them.

寿命测量<em&gt;果蝇</em

Aging is a phenomenon that results in steady physiological deterioration in nearly all organisms in which it has been examined, leading to reduced ...

Measurement of Vacuolar and Cytosolic pH In Vivo in Yeast Cell Suspensions

Vacuolar and cytosolic pH are highly regulated in yeast cells and occupy a central role in overall pH homeostasis. We describe protocols for ratiometric measurement of pH in vivo using pH-sensitive fluorophores localized to the vacuole or cytosol. Vacuolar pH is measured using BCECF, which localizes to the vacuole in yeast when introduced into cells in its acetoxymethyl ester form. Cytosolic pH is measured with a pH-sensitive GFP expressed under control of a yeast promoter, yeast pHluorin. Methods for measurement of fluorescence ratios in yeast cell suspensions in a fluorimeter are described. Through these protocols, single time point measurements of pH under different conditions or in different yeast mutants have been compared and changes in pH over time have been monitored. These methods have also been adapted to a fluorescence plate reader format for high-throughput experiments. Advantages of ratiometric pH measurements over other approaches currently in use, potential experimental problems and solutions, and prospects for future use of these techniques are also described.

Measurement of Vacuolar and Cytosolic pH In Vivo in Yeast Cell Suspensions

Vacuolar and cytosolic pH can be measured in live yeast (S. cerevisiae) cells using ratiometric fluorescent dyes localized to specific cellular compartments. We describe procedures for measuring vacuolar pH with BCECF-AM, which localizes to the vacuole in yeast, and cytosolic pH with a cytosolic ratiometric pH-sensitive GFP (yeast pHluorin).

液泡和胞质pH值的测量<em&gt;在体内</em在酵母细胞悬浮液

Vacuolar and  cytosolic pH are highly regulated in yeast cells and occupy a central role in  overall pH homeostasis. We describe  protocols for ...

Genetically-encoded Molecular Probes to Study G Protein-coupled Receptors

To facilitate structural and dynamic studies of G protein-coupled receptor (GPCR) signaling complexes, new approaches are required to introduce informative probes or labels into expressed receptors that do not perturb receptor function. We used amber codon suppression technology to genetically-encode the unnatural amino acid, p-azido-L-phenylalanine (azF) at various targeted positions in GPCRs heterologously expressed in mammalian cells. The versatility of the azido group is illustrated here in different applications to study GPCRs in their native cellular environment or under detergent solubilized conditions. First, we demonstrate a cell-based targeted photocrosslinking technology to identify the residues in the ligand-binding pocket of GPCR where a tritium-labeled small-molecule ligand is crosslinked to a genetically-encoded azido amino acid. We then demonstrate site-specific modification of GPCRs by the bioorthogonal Staudinger-Bertozzi ligation reaction that targets the azido group using phosphine derivatives. We discuss a general strategy for targeted peptide-epitope tagging of expressed membrane proteins in-culture and its detection using a whole-cell-based ELISA approach. Finally, we show that azF-GPCRs can be selectively tagged with fluorescent probes. The methodologies discussed are general, in that they can in principle be applied to any amino acid position in any expressed GPCR to interrogate active signaling complexes.

We genetically-encode the unnatural amino acid, p-azido-L-phenylalanine at various targeted positions in GPCRs and show the versatility of the azido group in different applications. These include a targeted photocrosslinking technology to identify residues in the ligand-binding pocket of a GPCR, and site-specific bioorthogonal modification of GPCRs with a peptide-epitope tag or fluorescent probe.

基因编码的分子探针来研究G蛋白偶联受体

To facilitate structural and dynamic studies of G protein-coupled receptor (GPCR) signaling complexes, new approaches are required to introduce ...

Use of the Ramsay Assay to Measure Fluid Secretion and Ion Flux Rates in the Drosophila melanogaster Malpighian Tubule

Modulation of renal epithelial ion transport allows organisms to maintain ionic and osmotic homeostasis in the face of varying external conditions. The Drosophila&#160;melanogaster Malpighian (renal) tubule offers an unparalleled opportunity to study the molecular mechanisms of epithelial ion transport, due to the powerful genetics of this organism and the accessibility of its renal tubules to physiological study. Here, we describe the use of the Ramsay assay to measure fluid secretion rates from isolated fly renal tubules, with the use of ion-specific electrodes to measure sodium and potassium concentrations in the secreted fluid. This assay allows study of transepithelial fluid and ion fluxes of ~20 tubules at a time, without the need to transfer the secreted fluid to a separate apparatus to measure ion concentrations. Genetically distinct tubules can be analyzed to assess the role of specific genes in transport processes. Additionally, the bathing saline can be modified to examine the effects of its chemical characteristics, or drugs or hormones added. In summary, this technique allows the molecular characterization of basic mechanisms of epithelial ion transport in the Drosophila tubule, as well as regulation of these transport mechanisms.

Use of the Ramsay Assay to Measure Fluid Secretion and Ion Flux Rates in the Drosophila melanogaster Malpighian Tubule

This protocol describes the use of the Ramsay assay to measure fluid secretion rates from isolated Malpighian (renal) tubules from Drosophila melanogaster. In addition, the use of ion-specific electrodes to measure sodium and potassium concentrations in the secreted fluid, allowing calculation of transepithelial ion flux, is described.

使用拉姆齐试验来测量液体分泌和离子流率在<em&gt;果蝇</em&gt;马氏管

Modulation of renal epithelial ion transport allows organisms to maintain ionic and osmotic homeostasis in the face of varying external conditions. The ...

Maintenance of a Drosophila melanogaster Population Cage

Large quantities of DNA, RNA, proteins and other cellular components are often required for biochemistry and molecular biology experiments. The short life cycle of Drosophila enables collection of large quantities of material from embryos, larvae, pupae and adult flies, in a synchronized way, at a low economic cost. A major strategy for propagating large numbers of flies is the use of a fly population cage. This useful and common tool in the Drososphila community is an efficient way to regularly produce milligrams to tens of grams of embryos, depending on uniformity of developmental stage desired. While a population cage can be time consuming to set up, maintaining a cage over months takes much less time and enables rapid collection of biological material in a short period. This paper describes a detailed and flexible protocol for the maintenance of a Drosophila melanogaster population cage, starting with 1.5 g of harvested material from the previous cycle.

Maintenance of a Drosophila melanogaster Population Cage

This manuscript reports a detailed protocol for culturing, on a regular basis, a population of Drosophila melanogaster using a fly population cage.

的维持<em&gt;果蝇</em&gt;人口笼

Large quantities of DNA, RNA, proteins and other cellular components are often required for biochemistry and molecular biology experiments. The short life ...

Application of Genetically Encoded Fluorescent Nitric Oxide (NO&#8226;) Probes, the geNOps, for Real-time Imaging of NO&#8226; Signals in Single Cells

Nitric Oxide (NO&#8226;) is a small radical, which mediates multiple important cellular functions in mammals, bacteria and plants. Despite the existence of a large number of methods for detecting NO&#8226; in vivo and in vitro, the real-time monitoring of NO&#8226; at the single-cell level is very challenging. The physiological or pathological effects of NO&#8226; are determined by the actual concentration and dwell time of this radical. Accordingly, methods that allow the single-cell detection of NO&#8226; are highly desirable. Recently, we expanded the pallet of NO&#8226; indicators by introducing single fluorescent protein-based genetically encoded nitric oxide (NO&#8226;) probes (geNOps) that directly respond to cellular NO&#8226; fluctuations and, hence, addresses this need. Here we demonstrate the usage of geNOps to assess intracellular NO&#8226; signals in response to two different chemical NO&#8226;-liberating molecules. Our results also confirm that freshly prepared 3-(2-hydroxy-1-methyl-2-nitrosohydrazino)-N-methyl-1-propanamine (NOC-7) has a much higher potential to evoke change in intracellular NO&#8226; levels as compared with the inorganic NO&#8226; donor sodium nitroprusside (SNP). Furthermore, dual-color live-cell imaging using the green geNOps (G-geNOp) and the chemical Ca2+ indicator fura-2 was performed to visualize the tight regulation of Ca2+-dependent NO&#8226; formation in single endothelial cells. These representative experiments demonstrate that geNOps are suitable tools to investigate the real-time generation and degradation of single-cell NO&#8226; signals in diverse experimental setups.

This manuscript presents protocols for the application of novel genetically encoded nitric oxide (NO&#8226;) probes (geNOps) to monitor single cell NO&#8226; fluctuations in real-time using fluorescence microscopy. The Ca2+-triggered NO&#8226; formation on the level of individual endothelial cells was visualized by combining geNOps with a chemical Ca2+ sensor.

遗传编码的荧光一氧化氮的应用（NO•）探针，所述geNOps，用于在单细胞NO•信号的实时影像

Nitric Oxide (NO&#8226;) is a small radical, which mediates multiple important cellular functions in mammals, bacteria and plants. Despite the existence ...

Optical Cross-Sectional Muscle Area Determination of Drosophila Melanogaster Adult Indirect Flight Muscles

Muscle mass wasting, known as muscle atrophy, is a common phenotype in Drosophila models of neuromuscular diseases. We have used the indirect flight muscles (IFMs) of flies, specifically the dorso-longitudinal muscles (DLM), as the experimental subject to measure the atrophic phenotype brought about by different genetic causes. In this protocol, we describe how to embed fly thorax muscles for semi thin sectioning, how to obtain a good contrast between muscle and the surrounding tissue, and how to process optical microscope images for semiautomatic acquisition of quantifiable data and analysis. We describe three specific applications of the methodological pipeline. First, we show how the method can be applied to quantify muscle degeneration in a myotonic dystrophy fly model; second, measurement of muscle cross-sectional area can help to identify genes that either promote or prevent muscle atrophy and/or muscle degeneration; third, this protocol can be applied to determine whether a candidate compound is able to significantly modify a given atrophic phenotype induced by a disease-causing mutation or by an environmental trigger.

Optical Cross-Sectional Muscle Area Determination of Drosophila Melanogaster Adult Indirect Flight Muscles

We report a method to quantify muscle area, which is an indirect method to determine muscle mass in Drosophila adults. We demonstrate the application of our methodology by analyzing the indirect flight muscles in a Drosophila model of Myotonic Dystrophy disease.

果蝇成人间接飞行肌的光学横截肌面积测定

Muscle mass wasting, known as muscle atrophy, is a common phenotype in Drosophila models of neuromuscular diseases. We have used the indirect flight ...