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+ Cell signaling
+ Genome editing
+ Morphogenesis
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Protocols in Past Issues

Simple Methods for Permanent or Transient Denervation in Mouse Sciatic Nerve Injury Models

AO Alexis Osseni
JT Jean-Luc Thomas
AG Alireza Ghasemizadeh
LS Laurent Schaeffer
VG Vincent Gache
4330 Views
Jun 5, 2022

Our ability to move and breathe requires an efficient communication between nerve and muscle that mainly takes place at the neuromuscular junctions (NMJs), a highly specialized synapse that links the axon of a motor neuron to a muscle fiber. When NMJs or axons are disrupted, the control of muscle fiber contraction is lost and muscle are paralyzed. Understanding the adaptation of the neuromuscular system to permanent or transient denervation is a challenge to understand the pathophysiology of many neuromuscular diseases. There is still a lack of in vitro models that fully recapitulate the in vivo situation, and in vivo denervation, carried out by transiently or permanently severing the nerve afferent to a muscle, remains a method of choice to evaluate reinnervation and/or the consequences of the loss of innervation. We describe here a simple surgical intervention performed at the hip zone to expose the sciatic nerve in order to obtain either permanent denervation (nerve-cut) or transient and reversible denervation (nerve-crush). These two methods provide a convenient in vivo model to study adaptation to denervation.


Graphical abstract:



Use of Optogenetic Amyloid-β to Monitor Protein Aggregation in Drosophila melanogaster, Danio rerio and Caenorhabditis elegans

PK Prameet Kaur
CK Caroline Kibat
ET Emelyne Teo
JG Jan Gruber
AM Ajay Mathuru
NT Nicholas S. Tolwinski
5956 Views
Dec 5, 2020

Alzheimer’s Disease (AD) has long been associated with accumulation of extracellular amyloid plaques (Aβ) originating from the Amyloid Precursor Protein. Plaques have, however, been discovered in healthy individuals and not all AD brains show plaques, suggesting that extracellular Aβ aggregates may play a smaller role than anticipated. One limitation to studying Aβ peptide in vivo during disease progression is the inability to induce aggregation in a controlled manner. We developed an optogenetic method to induce Aβ aggregation and tested its biological influence in three model organisms–D. melanogaster, C. elegans and D. rerio. We generated a fluorescently labeled, optogenetic Aβ peptide that oligomerizes rapidly in vivo in the presence of blue light in all organisms. Here, we detail the procedures for expressing this fusion protein in animal models, investigating the effects on the nervous system using time lapse light-sheet microscopy, and performing metabolic assays to measure changes due to intracellular Aβ aggregation. This method, employing optogenetics to study the pathology of AD, allows spatial and temporal control in vivo that cannot be achieved by any other method at present.

Probe-Seq: Method for RNA Sequencing of Specific Cell Types from Animal Tissue

RA Ryoji Amamoto
MG Mauricio D. Garcia
EW Emma R. West
JC Jiho Choi
SL Sylvain W. Lapan
EL Elizabeth A. Lane  [...]
CC Constance L. Cepko
+ 1 Author
7538 Views
Sep 20, 2020
Most organs and tissues are composed of many types of cells. To characterize cellular state, various transcription profiling approaches are currently available, including whole-tissue bulk RNA sequencing, single cell RNA sequencing (scRNA-Seq), and cell type-specific RNA sequencing. What is missing in this repertoire is a simple, versatile method for bulk transcriptional profiling of cell types for which cell type-specific genetic markers or antibodies are not readily available. We therefore developed Probe-Seq, which uses hybridization of gene-specific probes to RNA markers for isolation of specific types of cells, to enable downstream FACS isolation and bulk RNA sequencing. We show that this method can enable isolation and profiling of specific cell types from mouse retina, frozen human retina, Drosophila midgut, and developing chick retina, suggesting that it is likely useful for most organisms.

In vitro Osteoclastogenesis Assays Using Primary Mouse Bone Marrow Cells

XZ Xueqian Zhuang
Guohong Hu Guohong Hu
12310 Views
Jun 5, 2018
Osteoclasts are a group of bone-absorbing cells to degenerate bone matrix and play pivotal roles in bone growth and homeostasis. The unbalanced induction of osteoclast differentiation (osteoclastogenesis) in pathological conditions, such as osteoporosis, arthritis and skeleton metastasis of cancer, causes great pain, bone fracture, hypercalcemia or even death to patients. In vitro osteoclastogenesis analysis is useful to better understand osteoclast formation in physiological and pathological conditions. Here we summarized an easy-to-follow osteoclastogenesis protocol, which is suitable to evaluate the effect of different factors (cytokines, small molecular chemicals and conditioned medium from cell culture) on osteoclast differentiation using primary murine bone marrow cells.