We would like to thank Katharina Cosker and Stephanie Courchesne for helpful discussions.

Preparation of reagents
<ol>
<li>Collagen coating: collagen coat p35 tissue culture plates and place in an oven at 37&deg;C for 2 days before greasing the dividers.&nbsp;The final concentration of collagen should be at .71 mg/ml diluted in .001N HCl.&nbsp; Then, add 1 ml of mixture per plate.</li>
<li>Grease loaders: In order to fill the grease loader, a 60mL syringe must first be filled with Corning vacuum grease.&nbsp;Use the syringe to fill the grease loader, wrap it in foil and then autoclave for 45 minutes.</li>
<li>Teflon dividers: the dividers can be re-used after each experiment but must first be properly cleaned.&nbsp;Remove the divider from the plate, wipe off all of the remaining grease and place in sulfuric acid for 2 days. After removing from the acid, rinse with water 3X, boil for 20 minutes, allow to dry, place in a glass p100 petri dish and autoclave for 20 minutes.</li>
<li>N2-methylcellulose: Weigh out 1.5g of methylcellulose and place it in a 500mL bottle. Add a stir bar and autoclave it for 20 minutes on dry (from this point all work must be sterile). Next, add 500 mLs of serum free media (N2), and stir in a cold room until it dissolves.&nbsp;Aliquot into 50 mL conicals and freeze at -20&deg;C.&nbsp; For working stock, aliquot one of the 50 mL conicals into 1mL tubes and freeze at -20&deg;C.</li>
<li>DRG media:&nbsp;DMEM, 5% Heat inactivated horse serum, and 1% penicillin streptomycin.</li>
<li>100ng/mL DRGN media: The stock concentration of both nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) is 1mg/mL.&nbsp;Dilute each of the neurotrophins 1:10,000 into the DRG media.&nbsp;Cultures can be grown in NGF alone; this alters the complement of neurons that survive in the cultures. Note: When needed, the concentration of (cytosine arabinoside) AraC is 1uM and used at a final concentration of 0.3uM.&nbsp;This will inhibit growth of Schwann cells and other glia. </li>
<li>10ng/mL DRGN media:&nbsp; Dilute the 100ng/mL DRGN media (1:10) with DRG media. <img src="/files/ftp_upload/old/951_2008_10_27_6/951_Figure-01.png" alt="Figure 1" width="392" height="294" /> Figure 1. Tools needed for set-up </li>
</ol>
Setting up the compartmented chambers (start this process 1-2 days before the dissection)
<ol>
<li>Make a scratch in the middle of a collagen coated p35 dish with an outward motion.</li>
<li>Place 30ul of N2-methylcellulose on the middle of the scratch.&nbsp;Set dishes aside until divider is greased.</li>
<li>Attach a 23-gauge luer stub adapter to the grease loader.&nbsp;Grip the Teflon divider with a pair of 90&deg; angle hemostats and lay it flat with the divider facing up under a microscope.&nbsp;Trace the divider with grease making sure that each time the adapter is placed at a new starting point the adapter is inserted into the grease from the previous step so that there is a continuous line of grease (see diagram).&nbsp;Once the grease is applied to the entire divider, turn one of the prepared p35 dishes upside down and place it so the N2-methylcellulose is over the middle compartment. Press down on the bottom of the dish with a pair of tweezers.&nbsp;Make sure to press on the inside of the divider in four corners (upper left, lower right, upper right, lower left, indicated in diagram by "X"). <img src="/files/ftp_upload/old/951_2008_10_9_2/951_Figure-02.png" alt="Figure 2" width="171" height="183" /> Figure 2: Steps to greasing the divider Note: It is important to press firmly enough so that the grease makes a complete seal with the dish, but if too much pressure is added, the axons will not cross into the side compartments.&nbsp; Pick up the hemostats, turn it over and unclamp the divider. Lastly, place the dish with the divider firmly attached under the microscope focusing on the bottom of the middle compartment. With the grease loader, make a small barrier (.25cm) so that once the cells are placed in the middle compartment they cannot leak out. </li>
<li>After having set up several cultures, place DRG media in each of the side compartments and place in an incubator in which the cells will be maintained.&nbsp; Allow the cultures to sit for several hours and then check for leakage.&nbsp;If the media has leaked into the middle compartment, then the culture is unusable. Note: When first learning this technique, it is important to set up more cultures than&nbsp;are needed for an experiment, as several will be leaky. <img src="/files/ftp_upload/old/951_2008_10_9_3/951_Figure-03.png" alt="Figure 3" width="254" height="191" /> Figure 3: "Good vs leaky" culture </li>
</ol>
Maintaining DRG neurons in compartmented cultures
<ol>
<li>Day 1:&nbsp; Replace DRG media in the side compartments with 100ng/mL DRGN media + AraC.&nbsp; Perform dissection and add cells to center compartment (100,000 cells).&nbsp; </li>
<li>Day 2:&nbsp; Add 10ng/mL media + AraC to the outside of the Teflon divider until the media flows over the grease barrier and exchanges fluid with the center compartment.</li>
<li>Day 3:&nbsp; Replace media in the side compartments to 100ng/mL DRGN omitting the AraC and the surround with 10ng/mL DRGN omitting the AraC.</li>
<li>Day 6:&nbsp; Replace media in the side compartments to 1ng/mL + AraC and the surround with DRG media + AraC.</li>
<li>Day 9:&nbsp; Use for experimentation. <img src="/files/ftp_upload/old/951_2008_10_9_5/951_Figure-04.png" alt="Figure 4" width="267" height="148" /> Figure 4: IHC images of cell bodies and distal axons Note:&nbsp; When changing the media, it is important to aspirate the liquid from the top of the each side compartment.&nbsp;Also, never change the media from the middle compartment itself, only from the surround, and let it flow over the grease barrier into the center. </li>
</ol>

<ol>
	<li>Campenot, R. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Independent+Control+of+the+Local+Environment+of+Somas+and+Neurites.">Independent Control of the Local Environment of Somas and Neurites.</a> Methods in Enzymology. 58, 302-307 (1979).</li><li>Watson, F. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Neurotrophins+use+the+Erk5+pathway+to+mediate+a+retrograde+survival+response.">Neurotrophins use the Erk5 pathway to mediate a retrograde survival response.</a> Nature Neuroscience. 4, 981-988 (2001).</li><li>Heerssen, H. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dynein+motors+transport+activated+Trks+to+promote+survival+of+target-dependent+neurons.">Dynein motors transport activated Trks to promote survival of target-dependent neurons.</a> Nature Neuroscience. 7, 596-603 (2004).</li><li>Taylor, A. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+microfluidic+culture+platform+for+CNS+axonal+injury,+regeneration+and+transport.">A microfluidic culture platform for CNS axonal injury, regeneration and transport.</a> Nature Methods. 2, 599-605 (2006).</li><li>Park, J. W., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Microfluidic+culture+platform+for+neuroscience+research.">Microfluidic culture platform for neuroscience research.</a> Nat Protoc. 4, 2128-2136 (2006).</li><li>Ure, D. R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Retrograde+transport+and+steady-state+distribution+of+125I-nerve+growth+factor+in+rat+sympathetic+neurons+in+compartmented+cultures.">Retrograde transport and steady-state distribution of 125I-nerve growth factor in rat sympathetic neurons in compartmented cultures.</a> J Neuroscience. 4, 1282-1290 (1997).</li></ol>

In this video, we have demonstrated how to prepare and maintain compartmented chambers for use in culturing DRG neurons. Done properly, this system allows separation of the cell body from the axon in order to study mechanisms by which neurotrophins signal across long axons. Since there is fluidic isolation between the compartments, it allows for selective stimulation or treatment of one compartment without the other compartments being affected. Compartmented chamber cultures can support other cell types including sympath...

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">	
		
		<div>
		<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>collagen</td>
<td>Reagent</td>
<td>BD Biosciences</td>
<td>354249</td>
<td>&nbsp;</td>
<tr>
<td>N2-methylcellulose 400CPS</td>
<td>Reagent</td>
<td>Sel-Win Chemicals</td>
<td>&nbsp;</td>
<td>&nbsp;</td>
<tr>
<td>Teflon divider</td>
<td>Other</td>
<td>Tyler Research</td>
<td>CAMP10</td>
<td>many other types of dividers are available</td>
</tr>
<tr>
<td>Pin rake</td>
<td>Tool</td>
<td>Tyler Research</td>
<td>Camp-PR</td>
<td>&nbsp;</td>
<tr>
<td>Grease loader</td>
<td>Tool</td>
<td>Tyler Research</td>
<td>Camp-GLSS</td>
<td>&nbsp;</td>
<tr>
<td>DMEM</td>
<td>Reagent</td>
<td>Fisher</td>
<td>MT10017CV</td>
<td>&nbsp;</td>
<tr>
<td>NGF</td>
<td>Reagent</td>
<td>Peprotech</td>
<td>450-01</td>
<td>&nbsp;</td>
<tr>
<td>BDNF</td>
<td>Reagent</td>
<td>Peprotech</td>
<td>450-02</td>
<td>&nbsp;</td>
<tr>
<td>High vacuum grease</td>
<td>Reagent</td>
<td>Fisher</td>
<td>14-635-5D</td>
<td>&nbsp;</td>
<tr>
<td>AraC</td>
<td>Reagent</td>
<td>Sigma</td>
<td>C-1768</td>
<td>&nbsp;</td>
<tr>
<td>23 gauge luer stub adapter</td>
<td>Tool</td>
<td>Fisher</td>
<td>427565</td>
<td>&nbsp;</td>
<tr>
<td>90&deg; angle hemostats</td>
<td>Tool</td>
<td>Roboz</td>
<td>RS-7035</td>
<td>&nbsp;</td>		</tbody>
		</table>
		</div>

preparation and maintenance of dorsal root ganglia neurons in compartmented cultures

Neurons extend axonal processes that are far removed from the cell body to innervate target tissues, where target-derived growth factors are required for neuronal survival and function. Neurotrophins are specifically required to maintain the survival and differentiation of innervating sensory neurons but the question of how these target-derived neurotrophins communicate to the cell body of innervating neurons has been an area of active research for over 30 years. The most commonly accepted model of how neurotrophin signals reach the cell body proposes that signaling endosomes carry this signal retrogradely along the axon. In order to study retrograde transport, a culture system was originally devised by Robert Campenot, in which cell bodies are isolated from their axons. The technique of preparing these compartmented chambers for culturing sensory neurons recapitulates the selective stimulation of neuron terminals that occurs in vivo following release of target-derived neurotrophins. Retrograde signaling events that require long-range microtubule dependent retrograde transport have important implications for the treatment of neurodegenerative disorders.

Watch this Scientific Journal Video about Preparation and Maintenance of Dorsal Root Ganglia Neurons in Compartmented Cultures at JoVE.com

Preparation and Maintenance of Dorsal Root Ganglia Neurons in Compartmented Cultures

Here we describe the technique of preparing and maintaining compartmented chambers for culturing sensory neurons of the dorsal root ganglia.

Neurons extend axonal processes that are far removed from the cell body to innervate target tissues, where target-derived growth factors are required for ...

preparation-maintenance-dorsal-root-ganglia-neurons-compartmented

Research

JoVE Journal

Biology

22.3K ビュー.  Dana Farber Cancer Institute. ここでは、後根神経節の培養感覚ニューロンについてはコンパートメント室を準備し、維持するテクニックについて説明します。

ビデオ: Preparation and Maintenance of Dorsal Root Ganglia Neurons in Compartmented Cultures

Preparation of Neuronal Cultures from Midgastrula Stage Drosophila Embryos

This video illustrates the procedure for making primary neuronal cultures from midgastrula stage Drosophila embryos. The methods for collecting embryos and their dechorionation using bleach are demonstrated. Using a glass pipet attached to a mouth suction tube, we illustrate the removal of all cells from single embryos. The method for dispersing cells from each embyro into a small (5 l) drop of medium on an uncoated glass coverslip is demonstrated. A view through the microscope at 1 hour after plating illustrates the preferred cell density. Most of the cells that survive when grown in defined medium are neuroblasts that divide one or more times in culture before extending neuritic processes by 12-24 hours. A view through the microscope illustrates the level of neurite outgrowth and branching expected in a healthy culture at 2 days in vitro. The cultures are grown in a simple bicarbonate based defined medium, in a 5% CO2 incubator at 22-24&deg;C. Neuritic processes continue to elaborate over the first week in culture and when they make contact with neurites from neighboring cells they often form functional synaptic connections. Neurons in these cultures express voltage-gated sodium, calcium, and potassium channels and are electrically excitable. This culture system is useful for studying molecular genetic and environmental factors that regulate neuronal differentiation, excitability, and synapse formation/function.

This video demonstrates the preparation of primary neuronal cultures from midgastrula stage Drosophila embryos. Views of live cultures show cells 1 hour after plating and differentiated neurons after 2 days of growth in a bicarbonate-based defined medium. The neurons are electrically excitable and form synaptic connections.

This video illustrates the procedure for making primary neuronal cultures from midgastrula stage Drosophila embryos. The methods for collecting embryos ...

Preparation of Dissociated Mouse Cortical Neuron Cultures

This video will guide you through the process for generating cortical neuronal cultures from late embryo and early postnatal mouse brain. These cultures can be used for a variety of applications including immunocytochemistry, biochemistry, electrophysiology, calcium and sodium imaging, protein and/or RNA isolation. These cultures also provide a platform to study the neuronal development of transgenic animals that carry a late embryonic or postnatal lethal gene mutation. The procedure is relatively straight forward, requires some experience in tissue culture technique and should not take longer than two to three hours if you are properly prepared. Careful separation of the cortical rind from the thalamo-cortical fiber tract will reduce the number of unwanted non-neuronal cells. To increase yields of neuronal cells triturate the pieces of the cortical tissue gently after the enzyme incubation step. This is imperative as it prevents unnecessary injury to cells and premature neuronal cell death. Since these cultures are maintained in the absence of glia feeder cells, they also offer an added advantage of growing cultures enriched in neurons.

This video shows a procedure for generating neuronal cultures from late embryo and early postnatal mouse cortex. These cultures can be used for immunocytochemistry, biochemistry, electrophysiology, calcium and sodium imaging and provide a platform to study the neuronal development of transgenic animals that carry a postnatal lethal gene mutation.

This video will guide you through the process for generating cortical neuronal cultures from late embryo and early postnatal mouse brain. These cultures ...

Preparation of Gene Gun Bullets and Biolistic Transfection of Neurons in Slice Culture

Biolistic transfection is a physical means of transfecting cells by bombarding tissue with high velocity DNA coated particles. We provide a detailed protocol for biolistic transfection of rat hippocampal slices, from the initial preparation of DNA coated bullets to the final shooting of the organotypic slice cultures using a gene gun. Gene gun transfection is an efficient and easy means of transfecting neurons and is especially useful for fluorescently labeling a small subset of cells in tissue slice. In this video, we first outline the steps required to coat gold particles with DNA. We next demonstrate how to line the inside of plastic tubing with the gold/DNA bullets, and how to cut this tubing to obtain the plastic cartridges for loading into the gene gun. Finally, we perform biolistic transfection of rat hippocampal slice cultures, demonstrating handling of the Bio-Rad Helios gene gun, and offering trouble shooting advice to obtain healthy and optimally transfected tissue slices.  

We describe a method for preparing DNA coated gold bullets and demonstrate the use of such bullets to biolistically transfect neurons in cultured hippocampal slices.

Biolistic transfection is a physical means of transfecting cells by bombarding tissue with high velocity DNA coated particles. We provide a detailed ...

Preparation of 2-dGuo-Treated Thymus Organ Cultures

In the thymus, interactions between developing T-cell precursors and stromal cells that include cortical and medullary epithelial cells are known to play a key role in the development of a functionally competent T-cell pool. However, the complexity of T-cell development in the thymus in vivo can limit analysis of individual cellular components and particular stages of development. In vitro culture systems provide a readily accessible means to study multiple complex cellular processes. Thymus organ culture systems represent a widely used approach to study intrathymic development of T-cells under defined conditions in vitro. Here we describe a system in which mouse embryonic thymus lobes can be depleted of endogenous haemopoeitic elements by prior organ culture in 2-deoxyguanosine, a compound that is selectively toxic to haemopoeitic cells. As well as providing a readily accessible source of thymic stromal cells to investigate the role of thymic microenvironments in the development and selection of T-cells, this technique also underpins further experimental approaches that include the reconstitution of alymphoid thymus lobes in vitro with defined haemopoietic elements, the transplantation of alymphoid thymuses into recipient mice, and the formation of reaggregate thymus organ cultures. (This article is based on work first reported Methods in Molecular Biology 2007, Vol. 380 pages 185-196).

This video demonstrates the dissection and removal of the fetal thymus as well the preparation of ex vivo cultures of 2-dGuo-treated thymus.

In the thymus, interactions between developing T-cell precursors and stromal cells that include cortical and medullary epithelial cells are known to play ...

Protocol for Culturing Sympathetic Neurons from Rat Superior Cervical Ganglia (SCG)

The superior cervical ganglia (SCG) in rats are small, glossy, almond-shaped structures that contain sympathetic neurons.  These neurons provide sympathetic innervations for the head and neck regions and they constitute a well-characterized and relatively homogeneous population (4).  Sympathetic neurons are dependent on nerve growth factor (NGF) for survival, differentiation and axonal growth and the wide-spread availability of NGF facilitates their culture and experimental manipulation (2, 3, 6).  For these reasons, cultured sympathetic neurons have been used in a wide variety of studies including neuronal development and differentiation, mechanisms of programmed and pathological cell death, and signal transduction (1, 2, 5, and 6).  Dissecting out the SCG from newborn rats and culturing sympathetic neurons is not very complicated and can be mastered fairly quickly.  In this article, we will describe in detail how to dissect out the SCG from newborn rat pups and to use them to establish cultures of sympathetic neurons.  The article will also describe the preparatory steps and the various reagents and equipment that are needed to achieve this.

Protocol for Culturing Sympathetic Neurons from Rat Superior Cervical Ganglia SCG

This is a protocol describing how to isolate and culture primary sympathetic neurons from superior cervical ganglia (SCG) of newborn rat pups.

The superior cervical ganglia (SCG) in rats are small, glossy, almond-shaped structures that contain sympathetic neurons.  These neurons provide ...

Preparation of Aplysia Sensory-motor Neuronal Cell Cultures

The nervous system of the marine mollusk Aplysia californica is relatively simple, consisting of approximately 20,000 neurons. The neurons are large (up to 1 mm in diameter) and identifiable, with distinct sizes, shapes, positions and pigmentations, and the cell bodies are externally exposed in five paired ganglia distributed throughout the body of the animal. These properties have allowed investigators to delineate the circuitry underlying specific behaviors in the animal1. The monosynaptic connection between sensory and motor neurons is a central component of the gill-withdrawal reflex in the animal, a simple defensive reflex in which the animal withdraws its gill in response to tactile stimulation of the siphon. This reflex undergoes forms of non-associative and associative learning, including sensitization, habituation and classical conditioning. Of particular benefit to the study of synaptic plasticity, the sensory-motor synapse can be reconstituted in culture, where well-characterized stimuli elicit forms of plasticity that have direct correlates in the behavior of the animal2,3. Specifically, application of serotonin produces a synaptic strengthening that, depending on the application protocol, lasts for minutes (short-term facilitation), hours (intermediate-term facilitation) or days (long-term facilitation). In contrast, application of the peptide transmitter FMRFamide produces a synaptic weakening or depression that, depending on the application protocol, can last from minutes to days (long-term depression). The large size of the neurons allows for repeated sharp electrode recording of synaptic strength over periods of days together with microinjection of expression vectors, siRNAs and other compounds to target specific signaling cascades and molecules and thereby identify the molecular and cell biological steps that underlie the changes in synaptic efficacy.
An additional advantage of the Aplysia culture system comes from the fact that the neurons demonstrate synapse-specificity in culture4,5. Thus, sensory neurons do not form synapses with themselves (autapses) or with other sensory neurons, nor do they form synapses with non-target identified motor neurons in culture. The varicosities, sites of synaptic contact between sensory and motor neurons, are large enough (2-7 microns in diameter) to allow synapse formation (as well as changes in synaptic morphology) with target motor neurons to be studied at the light microscopic level.
In this video, we demonstrate each step of preparing sensory-motor neuron cultures, including anesthetizing adult and juvenile Aplysia, dissecting their ganglia, protease digestion of the ganglia, removal of the connective tissue by microdissection, identification of both sensory and motor neurons and removal of each cell type by microdissection, plating of the motor neuron, addition of the sensory neuron and manipulation of the sensory neurite to form contact with the cultured motor neuron.

Preparation of Aplysia Sensory-motor Neuronal Cell Cultures

Primary cultures of Aplysia sensory-motor neurons provide a model preparation for studying synapse formation and synaptic plasticity in vitro. This video demonstrates the identification and microdissection of sensory and motor neurons from Aplysia ganglia as well as the methods for establishing and maintaining sensory-motor neurons in culture.

The nervous system of the marine mollusk Aplysia californica is relatively simple, consisting of approximately 20,000 neurons.  The neurons are large (up ...

Alternative Cultures for Human Pluripotent Stem Cell Production, Maintenance, and Genetic Analysis

Human pluripotent stem cells (hPSCs) hold great promise for regenerative medicine and biopharmaceutical applications. Currently, optimal culture and efficient expansion of large amounts of clinical-grade hPSCs are critical issues in hPSC-based therapies. Conventionally, hPSCs are propagated as colonies on both feeder and feeder-free culture systems. However, these methods have several major limitations, including low cell yields and generation of heterogeneously differentiated cells. To improve current hPSC culture methods, we have recently developed a new method, which is based on non-colony type monolayer (NCM) culture of dissociated single cells. Here, we present detailed NCM protocols based on the Rho-associated kinase (ROCK) inhibitor Y-27632. We also provide new information regarding NCM culture with different small molecules such as Y-39983 (ROCK I inhibitor), phenylbenzodioxane (ROCK II inhibitor), and thiazovivin (a novel ROCK inhibitor). We further extend our basic protocol to cultivate hPSCs on defined extracellular proteins such as the laminin isoform 521 (LN-521) without the use of ROCK inhibitors. Moreover, based on NCM, we have demonstrated efficient transfection or transduction of plasmid DNAs, lentiviral particles, and oligonucleotide-based microRNAs into hPSCs in order to genetically modify these cells for molecular analyses and drug discovery. The NCM-based methods overcome the major shortcomings of colony-type culture, and thus may be suitable for producing large amounts of homogeneous hPSCs for future clinical therapies, stem cell research, and drug discovery.

Here, we present human pluripotent stem cell (hPSC) culture protocols, based on non-colony type monolayer (NCM) growth of dissociated single cells. This new method, utilizing Rho-associated kinase inhibitors or the laminin isoform 521 (LN-521), is suitable for producing large amounts of homogeneous hPSCs, genetic manipulation, and drug discovery.

Human pluripotent stem cells (hPSCs) hold great promise for regenerative medicine and biopharmaceutical applications. Currently, optimal culture and ...

Lateral Root Inducible System in Arabidopsis and Maize

Lateral root development contributes significantly to the root system, and hence is crucial for plant growth. The study of lateral root initiation is however tedious, because it occurs only in a few cells inside the root and in an unpredictable manner. To circumvent this problem, a Lateral Root Inducible System (LRIS) has been developed. By treating seedlings consecutively with an auxin transport inhibitor and a synthetic auxin, highly controlled lateral root initiation occurs synchronously in the primary root, allowing abundant sampling of a desired developmental stage. The LRIS has first been developed for Arabidopsis thaliana, but can be applied to other plants as well. Accordingly, it has been adapted for use in maize (Zea mays). A detailed overview of the different steps of the LRIS in both plants is given. The combination of this system with comparative transcriptomics made it possible to identify functional homologs of Arabidopsis lateral root initiation genes in other species as illustrated here for the CYCLIN B1;1 (CYCB1;1) cell cycle gene in maize. Finally, the principles that need to be taken into account when an LRIS is developed for other plant species are discussed.

Lateral Root Inducible System in Arabidopsis and Maize

The Lateral Root Inducible System (LRIS) allows for synchronous induction of lateral roots and is presented for Arabidopsis thaliana and maize.

Lateral root development contributes significantly to the root system, and hence is crucial for plant growth. The study of lateral root initiation is ...

Divergence of Root Microbiota in Different Habitats based on Weighted Correlation Networks

The root microbiome plays an important role in plant growth and environmental adaptation. Network analysis is an important tool for studying communities, which can effectively explore the interaction relationship or co-occurrence model of different microbial species in different environments. The purpose of this manuscript is to provide details on how to use the weighted correlation network algorithm to analyze different co-occurrence networks that may occur in microbial communities due to different ecological environments. All analysis of the experiment is performed in the WGCNA package. WGCNA is an R package for weighted correlation network analysis. The experimental data used to demonstrate these methods were microbial community data from the NCBI (National Center for Biotechnology Information) database for three niches of the rice (Oryza sativa) root system. We used the weighted correlation network algorithm to construct co-abundance networks of microbial community in each of the three niches. Then, differential co-abundance networks among endosphere, rhizoplane and rhizosphere soil were identified. In addition, the core genera in network were obtained by the "WGCNA" package, which plays an important regulated role in network functions. These methods enable researchers to analyze the response of microbial network to environmental disturbance and verify different microbial ecological response theories. The results of these methods show that the significant differential microbial networks identified in the endosphere, rhizoplane and rhizosphere soil of rice.

Network analysis was applied to evaluate the association of various ecological microbial communities, such as soil, water and rhizosphere. Presented here is a protocol on how to use the WGCNA algorithm to analyze different co-occurrence networks that may occur in the microbial communities due to different ecological environments.

The root microbiome plays an important role in plant growth and environmental adaptation. Network analysis is an important tool for studying communities, ...

An Improved Chemotaxis Assay for the Rapid Identification of Rhizobacterial Chemoattractants in Root Exudates

Chemotaxis identification is very important for the research and application of rhizosphere growth-promoting bacteria. We established a straightforward method to quickly identify the chemoattractants that could induce the chemotactic movement of rhizosphere growth-promoting bacteria on sterile glass slides via simple steps. Bacteria solution (OD600 = 0.5) and sterile chemoattractant aqueous solution were added dropwise on the glass slide at an interval of 1 cm. An inoculating loop was used to connect the chemoattractant aqueous solution to the bacterial solution. The slide was kept at room temperature for 20 min on the clean bench. Finally, the chemoattractant aqueous solution was collected for bacterial counting and microscopic observation. In this study, through multiple comparisons of experimental results, the method overcame multiple shortcomings of traditional bacterial chemotaxis methods. The method reduced the error of plate counting and shortened the experimental cycle. For the identification of chemoattractant substances, this new method can save 2-3 days compared to the traditional method. Additionally, this method allows any researcher to systematically complete a bacterial chemotaxis experiment within 1-2 days. The protocol can be considered a valuable resource for understanding plant-microbe interactions.

Here, we present an improved chemotaxis assay protocol. The goal of this protocol is to reduce the steps and costs of traditional bacterial chemotaxis methods and to serve as a valuable resource for understanding plant-microbe interactions.

Chemotaxis identification is very important for the research and application of rhizosphere growth-promoting bacteria. We established a straightforward ...