ai_agent

<meta charset="utf8"></head><body>在恒定气压下显微注射针的湿斜面协议

<ol><li>Rubin, G. M., Spradling, A. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Genetic+transformation+of+Drosophila+with+transposable+Element+Vectors%5BTitle%5D)+AND+%22Science%22%5BJournal%5D)">Genetic transformation of Drosophila with transposable Element Vectors.</a> Science. 218 (4570), 348-353 (1982).</li>
<li>O'Brochta, D. A., Atkinson, P. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Transformation+systems+in+insects%5BTitle%5D)+AND+%22Methods+Mol+Biol%22%5BJournal%5D)">Transformation systems in insects.</a> Methods Mol Biol. 260, 227-254 (2004).</li>
<li>Handler, A. M., James, A. A. <a target="_blank" href="http://scholar.google.com/scholar?hl=en&safe=off&q=author%3aHandler%2C+AM+%22Insect+Transgenesis%3A+Methods+and+Applications%22">Insect Transgenesis: Methods and Applications</a>. , CRC Press. Boca Rato. (2000).</li>
<li>Harrell, R. A. Mosquito embryo microinjection. <a target="_blank" href="http://scholar.google.com/scholar?hl=en&safe=off&q=author%3aHarrell%2C+RA+%22Cold+Spring+Harbor+Protocols%22">Cold Spring Harbor Protocols</a>. , 10.1101/pdb.prot107686 (2023).</li>
<li>Allen, M. L., O'Brochta, D. A., Atkinson, P. W., Levesque, C. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Stable%2C+germ-line+transformation+of+Culex+Quinquefasciatus+%28Diptera%3A+Culicidae%29%5BTitle%5D)+AND+%22J+Med+Entomol%22%5BJournal%5D)">Stable, germ-line transformation of Culex Quinquefasciatus (Diptera: Culicidae).</a> J Med Entomol. 38 (5), 701-710 (2001).</li>
<li>Grossman, G. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Germline+transformation+of+the+malaria+vector%2C+Anopheles+gambiae%2C+with+the+piggyBac+transposable+element%5BTitle%5D)+AND+%22Insect+Mol+Biol%22%5BJournal%5D)">Germline transformation of the malaria vector, Anopheles gambiae, with the piggyBac transposable element.</a> Insect Mol Biol. 10 (6), 597-604 (2001).</li>
<li>Adelman, Z. N., Jasinskiene, N., James, A. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Development+and+applications+of+transgenesis+in+the+yellow+fever+mosquito%2C+Aedes+aegypti%5BTitle%5D)+AND+%22Mol+Biochem+Parasitol%22%5BJournal%5D)">Development and applications of transgenesis in the yellow fever mosquito, Aedes aegypti.</a> Mol Biochem Parasitol. 121 (1), 1-10 (2002).</li>
<li>Perera, O. P., Harrell, R. A., Handler, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Germ-line+transformation+of+the+South+American+malaria+vector%2C+Anopheles+albimanus%2C+with+a+piggyBac%2FEGFP+transposon+vector+is+routine+and+highly+efficient%5BTitle%5D)+AND+%22Insect+Mol+Biol%22%5BJournal%5D)">Germ-line transformation of the South American malaria vector, Anopheles albimanus, with a piggyBac/EGFP transposon vector is routine and highly efficient.</a> Insect Mol Biol. 11 (4), 291-297 (2002).</li>
<li>Harrell, R. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Mosquito+embryo+microinjection+under+halocarbon+oil+or+in+aqueous+solution%5BTitle%5D)+AND+%22Cold+Spring+Harb+Protoc%22%5BJournal%5D)">Mosquito embryo microinjection under halocarbon oil or in aqueous solution.</a> Cold Spring Harb Protoc. , 10.1101/pdb.prot108203 (2023).</li>
<li>Louradour, I., Ghosh, K., Inbar, E., Sacks, D. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((CRISPR%2FCas9+mutagenesis+in+Phlebotomus+papatasi%3A+The+immune+deficiency+pathway+impacts+vector+competence+for+Leishmania+major%5BTitle%5D)+AND+%22mBio%22%5BJournal%5D)">CRISPR/Cas9 mutagenesis in Phlebotomus papatasi: The immune deficiency pathway impacts vector competence for Leishmania major.</a> mBio. 10 (4), e01941(2019).</li>
<li>Tamura, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Germline+transformation+of+the+silkworm+Bombyx+mori+L.+using+a+piggyBac+transposon-derived+vector%5BTitle%5D)+AND+%22Nat+Biotechnol%22%5BJournal%5D)">Germline transformation of the silkworm Bombyx mori L. using a piggyBac transposon-derived vector.</a> Nat Biotechnol. 18 (1), 81-84 (2000).</li>
<li>BV-10 Micropipette Beveler Operation Manual Rev. 3.00. , Available from: 
 <a target="_blank" href="https://www.manualslib.com/manual/2073788/Sutter-Instrument-Bv-10.html">https://www.manualslib.com/manual/2073788/Sutter-Instrument-Bv-10.html</a> (2018).</li>
</ol>

<table><tbody><tr><td>1.0 mm O.D. microcapillaries</td><td>World Precision Instruments</td><td></td><td></td></tr><tr><td>Beveler pedestal oil</td><td>Sutter Instruments</td><td>008</td><td></td></tr><tr><td>Bicycle fender clip</td><td>VeloOrange</td><td>R-clip 4-pack</td><td>https://velo-orange.com/products/vo-r-clip-4-pack</td></tr><tr><td>Boom Stand Microscope</td><td>AmScope</td><td></td><td>AMScope 3.5X-90X Trinocular LED Boom Stand Stereo Microscope or equivalent</td></tr><tr><td>BV-10 Beveler</td><td>Sutter Instruments</td><td>BV-10</td><td></td></tr><tr><td>Diamond abrasive plate&amp;nbsp;</td><td>Sutter Instruments</td><td>104F</td><td>Diamond abrasive plate - extra fine (0.2 &amp;micro; to 1.0 &amp;micro; tip sizes)</td></tr><tr><td>Gasket, Buna-N</td><td>Clippard Instrument Laboratory, Inc.</td><td>11761-2-pkg</td><td>Used to seal connection on T&amp;nbsp; or L connectors, if not already included with these pieces</td></tr><tr><td>Hose Clamp</td><td>Clippard Instrument Laboratory, Inc.</td><td>5000-2-pkg</td><td></td></tr><tr><td>Hose connector</td><td>Clippard Instrument Laboratory, Inc.</td><td>CT4-pkg</td><td>Need 5 hose connectors</td></tr><tr><td>Microinjection Needle Holder</td><td>World Precision Instruments</td><td>MPH3-10</td><td>Needle holder for 1mm outer diameter microcapillaries</td></tr><tr><td>P-2000</td><td>Sutter Instruments</td><td></td><td>Any needle puller</td></tr><tr><td>Photo-Flo 200 Solution</td><td>B&amp;amp;H Photo, Video and Audio</td><td>BH #KOPF200P&amp;nbsp; MFR #1464510</td><td>wetting agent</td></tr><tr><td>Pressure Gauge</td><td>Clippard Instrument Laboratory, Inc.</td><td>PG-100</td><td>0-100 psi gauge</td></tr><tr><td>Reference wick</td><td>Sutter Instruments</td><td>X050300</td><td></td></tr><tr><td>Reference wick holder</td><td>Sutter Instruments</td><td>M100019</td><td></td></tr><tr><td>Regulator</td><td>Clippard Instrument Laboratory, Inc.</td><td>01-Mar</td><td>Need #10-32 ports for connections</td></tr><tr><td>Rubber Packing Sheet 6 inx 6 in</td><td>Danco</td><td>Model # 59849</td><td></td></tr><tr><td>T fitting</td><td>Clippard Instrument Laboratory, Inc.</td><td>15002-2-pkg</td><td></td></tr><tr><td>Threaded Bar</td><td></td><td></td><td>Either a threaded rod or bar with threaded end. Threads must be 10-32.</td></tr><tr><td>Urethane tubing</td><td>Clippard Instrument Laboratory, Inc.</td><td>URH1-0804-BLT-050</td><td></td></tr></tbody></table>

wet beveling of microinjection needles utilizing constant air pressure for feedback on needle opening

<meta charset="utf8"></head><body>作者聚焦:通过湿式斜面提高显微注射针质量

利用恒定气压对针头开口进行湿式坡口

Microinjection needles are a critical tool in the delivery of genome modification reagents, CRISPR components (guide RNAs, Cas9 protein, and donor ...

wet-beveling-microinjection-needles-utilizing-constant-air-pressure

Research

JoVE Journal

Biology

Wet Beveling of Microinjection Needles Utilizing Constant Air Pressure for Feedback on Needle Opening

648 次观看.  University of Maryland. 昆虫转化设施，我们是一家大学服务机构，帮助客户制造转基因昆虫。他们的研究范围从神经科学（他们正在进行蚊子嗅觉研究）到公共卫生研究（他们正在制造疟疾疫苗），再到在黑水虻中表达新蛋白质。传统上，针头是通过拉动针头，然后用刷子刷在某物上以打开针头，这样可以产生非常适合显微注射或无法使用的针头。因此，这种方法使...

视频: 作者聚焦:通过湿式斜面提高显微注射针质量

Microinjection-Based Delivery of a Therapeutic Agent into an Awake Rodent Brain

Source: <a href='https://app.jove.com/v/53018/rodent-brain-microinjection-to-study-molecular-substrates-motivated'>Poland, R. et al. Rodent Brain Microinjection to Study Molecular Substrates of Motivated Behavior. J. Vis. Exp. (2015)</a>In this video, a water-filled microinjection setup consisting of a syringe and microinjector tubing is used for precise drug delivery. A rat with a pre-implanted guide cannula undergoes targeted brain microinjection, enabling accurate administration of therapeutic agents in awake animals with minimal tissue damage.

基于显微注射将治疗剂递送至清醒的啮齿动物大脑

Source: Poland, R. et al. Rodent Brain Microinjection to Study Molecular Substrates of Motivated Behavior. J. Vis. Exp. (2015)In this video, a ...

科研

JoVE Encyclopedia of Experiments

Neuroscience

Neurotherapeutics

Drug Delivery

Rodent Brain Microinjection to Study Molecular Substrates of Motivated Behavior

Brain microinjection can aid elucidation of the molecular substrates of complex behaviors, such as motivation. For this purpose rodents can serve as appropriate models, partly because the response to behaviorally relevant stimuli and the circuitry parsing stimulus-action outcomes is astonishingly similar between humans and rodents. In studying molecular substrates of complex behaviors, the microinjection of reagents that modify, augment, or silence specific systems is an invaluable technique. However, it is crucial that the microinjection site is precisely targeted in order to aid interpretation of the results. We present a method for the manufacture of surgical implements and microinjection needles that enables accurate microinjection and unlimited customizability with minimal cost. Importantly, this technique can be successfully completed in awake rodents if conducted in conjunction with other JoVE articles that covered requisite surgical procedures. Additionally, there are many behavioral paradigms that are well suited for measuring motivation. The progressive ratio is a commonly used method that quantifies the efficacy of a reinforcer to maintain responding despite an (often exponentially) increasing work requirement. This assay is sensitive to reinforcer magnitude and pharmacological manipulations, which allows reinforcing efficacy and/ or motivation to be determined. We also present a straightforward approach to program operant software to accommodate a progressive ratio reinforcement schedule.

啮齿动物脑显微注射研究动机行为的分子底物

Rodents are an appropriate model to investigate the molecular substrates of behavior and complex psychiatric disorders. Brain microinjection in awake rodents can be used to elucidate disease substrates. An efficient and customizable brain microinjection method as well as the execution of an operant paradigm that quantifies motivation is presented.

啮齿动物脑显微注射学习动机行为的分子基板

Brain microinjection can aid elucidation of the molecular substrates of complex behaviors, such as motivation. For this purpose rodents can serve as ...

行为学

Personalized Needles for Microinjections in the Rodent Brain

Microinjections have been used for a long time for the delivery of drugs or toxins within specific brain areas and, more recently, they have been used to deliver gene or cell therapy products. Unfortunately, current microinjection techniques use steel or glass needles that are suboptimal for multiple reasons: in particular, steel needles may cause tissue damage, and glass needles may bend when lowered deeply into the brain, missing the target region. In this article, we describe a protocol to prepare and use quartz needles that combine a number of useful features. These needles do not produce detectable tissue damage and, being very rigid, ensure reliable delivery in the desired brain region even when using deep coordinates. Moreover, it is possible to personalize the design of the needle by making multiple holes of the desired diameter. Multiple holes facilitate the injection of large amounts of solution within a larger area, whereas large holes facilitate the injection of cells. In addition, these quartz needles can be cleaned and re-used, such that the procedure becomes cost-effective.

用于啮齿动物大脑显微注射的个性化针头

We describe here a protocol for microinjection in the rodent brain that uses quartz needles. These needles do not produce detectable tissue damage and ensure reliable delivery even in deep regions. Moreover, they can be adapted to research needs by personalized designs and can be re-used.

啮齿动物脑 Microinjections 的个性化针

Microinjections have been used for a long time for the delivery of drugs or toxins within specific brain areas and, more recently, they have been used to ...

神经科学

Micromanipulation Techniques Allowing Analysis of Morphogenetic Dynamics and Turnover of Cytoskeletal Regulators

Examining the spatiotemporal dynamics of proteins can reveal their functional importance in various contexts. In this article, it is discussed how fluorescent recovery after photobleaching (FRAP) and photoactivation techniques can be used to study the spatiotemporal dynamics of proteins in subcellular locations. We also show how these techniques enable straightforward determination of various parameters linked to actin cytoskeletal regulation and cell motility. Moreover, the microinjection of cells is additionally described as an alternative treatment (potentially preceding or complementing the aforementioned photomanipulation techniques) to trigger instantaneous effects of translocated proteins on cell morphology and function. Micromanipulation such as protein injection or local application of plasma membrane-permeable drugs or cytoskeletal inhibitors can serve as powerful tool to record immediate consequences of a given treatment on cell behavior at the single cell and subcellular level. This is exemplified here by immediate induction of lamellipodial cell edge protrusion by the injection of recombinant Rac1 protein, as established a quarter-century ago. In addition, we provide a protocol for determining the turnover of enhanced green fluorescent protein (EGFP)-VASP, an actin filament polymerase prominently accumulating at lamellipodial tips of B16-F1 cells, employing FRAP and including associated data analysis and curve fitting. We also present guidelines for estimating the rates of lamellipodial actin network polymerization, as exemplified by cells expressing EGFP-tagged &#946;-actin. Finally, instructions are given for how to investigate the rates of actin monomer mobility within the cell cytoplasm, followed by actin incorporation at sites of rapid filament assembly, such as the tips of protruding lamellipodia, using photoactivation approaches. None of these protocols is&#160;restricted to components or regulators of the actin cytoskeleton, but can easily be extended to explore in analogous fashion the spatiotemporal dynamics and function of proteins in various different subcellular structures or functional contexts.

显微作技术，允许分析形态发生动力学和细胞骨架调节因子的周转

We describe how micro- and photomanipulation techniques such as FRAP and photoactivation enable the determination of motility parameters and the spatiotemporal dynamics of proteins within migrating cells. Experimental readouts include subcellular dynamics and turnover of motility regulators or of the underlying actin cytoskeleton.

微操作系统技术允许分析骨架调节器的形态发生动力学和营业额

Examining the spatiotemporal dynamics of proteins can reveal their functional importance in various contexts. In this article, it is discussed how ...

生物学

In Vivo Calcium Imaging of Lateral-line Hair Cells in Larval Zebrafish

Sensory hair cells are mechanoreceptors found in the inner ear that are required for hearing and balance. Hair cells are activated in response to sensory stimuli that mechanically deflect apical protrusions called hair bundles. Deflection opens mechanotransduction (MET) channels in hair bundles, leading to an influx of cations, including calcium. This cation influx depolarizes the cell and opens voltage-gated calcium channels located basally at the hair-cell presynapse. In mammals, hair cells are encased in bone, and it is challenging to functionally assess these activities in vivo. In contrast, larval zebrafish are transparent and possess an externally located lateral-line organ that contains hair cells. These hair cells are functionally and structurally similar to mammalian hair cells and can be functionally assessed in vivo. This article outlines a technique that utilizes a genetically encoded calcium indicator (GECI), GCaMP6s, to measure stimulus-evoked calcium signals in zebrafish lateral-line hair cells. GCaMP6s can be used, along with confocal imaging, to measure in vivo calcium signals at the apex and base of lateral-line hair cells. These signals provide a real-time, quantifiable readout of both mechanosensation- and presynapse-dependent calcium activities within these hair cells. These calcium signals also provide important functional information regarding how hair cells detect and transmit sensory stimuli. Overall, this technique generates useful data about relative changes in calcium activity in vivo. It is less well-suited for quantification of the absolute magnitude of calcium changes. This in vivo technique is sensitive to motion artifacts. A reasonable amount of practice and skill are required for proper positioning, immobilization, and stimulation of larvae. Ultimately, when properly executed, the protocol outlined in this article provides a powerful way to collect valuable information about the activity of hair-cells in their natural, fully integrated states within a live animal.

斑马鱼幼虫侧线毛细胞的体内钙成像

The zebrafish is a model system that has many valuable features including optical clarity, rapid external development, and, of particular importance to the field of hearing and balance, externally located sensory hair cells. This article outlines how transgenic zebrafish can be used to assay both hair-cell mechanosensation and presynaptic function in toto.

幼虫斑马鱼外系头发细胞的活体钙成像

Sensory hair cells are mechanoreceptors found in the inner ear that are required for hearing and balance. Hair cells are activated in response to sensory ...

Microinjectrode System for Combined Drug Infusion and Electrophysiology

This microinjectrode system is designed for drug infusion, electrophysiology, and delivery and retrieval of experimental probes, such as microelectrodes and nanosensors, optimized for repeated use in awake, behaving animals. The microinjectrode system can be configured for multiple purposes: (1) simple arrangement of the cannula for placement of an experimental probe that would otherwise be too fragile to penetrate the dura mater, (2) microfluidic infusion of a drug, either independently or coupled to a cannula containing an experimental probe (i.e., microelectrode, nanosensor). In this protocol we explain the step by step construction of the microinjectrode, its coupling to microfluidic components, and the protocol for use of the system in vivo. The microfluidic components of this system allow for delivery of volumes on the nanoliter scale, with minimal penetration damage. Drug infusion can be performed independently or simultaneously with experimental probes such as microelectrodes or nanosensors in an awake, behaving animal. Applications of this system range from measuring the effects of a drug on cortical electrical activity and behavior, to understanding the function of a specific region of cortex in the context of behavioral performance based on probe or nanosensor measurements. To demonstrate some of the capabilities of this system, we present an example of muscimol infusion for reversible inactivation of the frontal eye field (FEF) in rhesus macaque during a working memory task.

用于药物输注和电生理学联合的显微注射系统

We present a microinjectrode system designed for electrophysiology and assisted delivery of experimental probes (i.e., nanosensors, microelectrodes), with optional drug infusion. Widely available microfluidic components are coupled to a cannula containing the probe. A step-by-step protocol for microinjectrode construction is included, with results during muscimol infusion in macaque cortex.

联合药物输液和电生理学的显微注射系统

This microinjectrode system is designed for drug infusion, electrophysiology, and delivery and retrieval of experimental probes, such as microelectrodes ...

Drosophila Embryo Preparation and Microinjection for Live Cell Microscopy Performed using an Automated High Content Analyzer

Modern approaches in quantitative live cell imaging have become an essential tool for exploring cell biology, by enabling the use of statistics and computational modeling to classify and compare biological processes. Although cell culture model systems are great for high content imaging, high throughput studies of cell morphology suggest that ex vivo cultures are limited in recapitulating the morphological complexity found in cells within living organisms. As such, there is a need for a scalable high throughput model system to image living cells within an intact organism. Described here is a protocol for using a high content image analyzer to simultaneously acquire multiple time-lapse videos of embryonic Drosophila melanogaster development during the syncytial blastoderm stage. The syncytial blastoderm has traditionally served as a great in vivo model for imaging biological events; however, obtaining a significant number of experimental replicates for quantitative and high-throughput approaches has been labor intensive and limited by the imaging of a single embryo per experimental repeat. Presented here is a method to adapt imaging and microinjection approaches to suit a high content imaging system, or any inverted microscope capable of automated multipoint acquisition. This approach enables the simultaneous acquisition of 6-12 embryos, depending on desired acquisition factors, within a single imaging session.

使用自动高内涵分析仪进行果蝇胚胎制备和活细胞显微镜显微注射

Presented here is a protocol to microinject and simultaneously image multiple Drosophila embryos during embryonic development using a plate-based, high content imager.

使用自动高含量分析仪进行活细胞显微镜的果蝇胚胎制备和微注射

Modern approaches in quantitative live cell imaging have become an essential tool for exploring cell biology, by enabling the use of statistics and ...

发育生物学

Preparing and Injecting Embryos of Culex Mosquitoes to Generate Null Mutations using CRISPR/Cas9

Culex mosquitoes are the major vectors of several diseases that negatively impact human and animal health including West Nile virus and diseases caused by filarial nematodes such as canine heartworm and elephantasis. Recently, CRISPR/Cas9 genome editing has been used to induce site-directed mutations by injecting a Cas9 protein that has been complexed with a guide RNA (gRNA) into freshly laid embryos of several insect species, including mosquitoes that belong to the genera Anopheles and Aedes. Manipulating and injecting Culex mosquitoes is slightly more difficult as these mosquitoes lay their eggs upright in rafts rather than individually like other species of mosquitoes. Here we describe how to design gRNAs, complex them with Cas9 protein, induce female mosquitoes of Culex pipiens to lay eggs, and how to prepare and inject newly laid embryos for microinjection with Cas9/gRNA. We also describe how to rear and screen injected mosquitoes for the desired mutation. The representative results demonstrate that this technique can be used to induce site-directed mutations in the genome of Culex mosquitoes and, with slight modifications, can be used to generate null-mutants in other mosquito species as well.&#160;

准备和注射库蚊胚胎以使用 CRISPR/Cas9 产生无效突变

CRISPR/Cas9 is increasingly used to characterize gene function in non-model organisms. This protocol describes how to generate knock-out lines of Culex pipiens, from preparing injection mixes, to obtaining and injecting mosquito embryos, as well as how to rear, cross, and screen injected mosquitoes and their progeny for desired mutations.

准备和注射 Culex 蚊子的胚胎，使用CRISPR/Cas9产生空突变

Culex mosquitoes are the major vectors of several diseases that negatively impact human and animal health including West Nile virus and diseases caused by ...

Microinjection of Xenopus Laevis Oocytes

Microinjection of Xenopus laevis oocytes followed by thin-sectioning electron microscopy (EM) is an excellent system for studying nucleocytoplasmic transport. Because of its large nucleus and high density of nuclear pore complexes (NPCs), nuclear transport can be easily visualized in the Xenopus oocyte. Much insight into the mechanisms of nuclear import and export has been gained through use of this system (reviewed by Pant&eacute;, 2006). In addition, we have used microinjection of Xenopus oocytes to dissect the nuclear import pathways of several viruses that replicate in the host nucleus. 
Here we demonstrate the cytoplasmic microinjection of Xenopus oocytes with a nuclear import substrate. We also show preparation of the injected oocytes for visualization by thin-sectioning EM, including dissection, dehydration, and embedding of the oocytes into an epoxy embedding resin. Finally, we provide representative results for oocytes that have been microinjected with the capsid of the baculovirus Autographa californica nucleopolyhedrovirus (AcMNPV) or the parvovirus Minute Virus of Mice (MVM), and discuss potential applications of the technique.

非洲爪蟾卵母细胞的显微注射

Here we demonstrate cytoplasmic microinjection of Xenopus laevis oocytes with a nuclear import substrate, as well as preparation of the injected oocytes for visualization by thin-sectioning electron microscopy.

非洲爪蟾卵母细胞的微量注射

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