Analyzing In Vivo Cell Migration using Cell Transplantations and Time-lapse Imaging in Zebrafish Embryos

Summary

Combining cell transplantation, cytoskeletal labeling and loss/gain of function approaches, this protocol describes how the migrating zebrafish prospective prechordal plate can be used to analyze the function of a candidate gene in in vivo cell migration.

Abstract

Cell migration is key to many physiological and pathological conditions, including cancer metastasis. The cellular and molecular bases of cell migration have been thoroughly analyzed in vitro. However, in vivo cell migration somehow differs from in vitro migration, and has proven more difficult to analyze, being less accessible to direct observation and manipulation. This protocol uses the migration of the prospective prechordal plate in the early zebrafish embryo as a model system to study the function of candidate genes in cell migration. Prechordal plate progenitors form a group of cells which, during gastrulation, undergoes a directed migration from the embryonic organizer to the animal pole of the embryo. The proposed protocol uses cell transplantation to create mosaic embryos. This offers the combined advantages of labeling isolated cells, which is key to good imaging, and of limiting gain/loss of function effects to the observed cells, hence ensuring cell-autonomous effects. We describe here how we assessed the function of the TORC2 component Sin1 in cell migration, but the protocol can be used to analyze the function of any candidate gene in controlling cell migration in vivo.

Introduction

In multicellular organisms, cell migration is essential both for the development of the embryo where it ensures the organization of cells into tissues and organs, and for adult life, where it takes part to tissue homeostasis (wound healing) and immunity. In addition to these physiological functions, cell migration is also involved in diverse pathological situations, including, in particular, cancer metastasis.

Cell migration has been analyzed in vitro for decades, providing an overall understanding of the molecular mechanisms ensuring cell movements on flat surfaces. In vivo however, cells are confronted by a more complex ....

Protocol

Note: Figure 1 presents the outline of the protocol.

1. Preparation of the Needles for Injection and Transplantation

Note: Needles can be prepared at any time and stored. Keep them in a Petri dish, on a band of modeling clay. Seal the dish with parafilm to protect from dust.

1. For injection needles, pull a glass capillary (outside diameter 1.0 mm, inside diameter 0.58 mm, without filament (see list of Materials)) with a micropipette puller (see list of Materials). Prefer short and thin needles (tapered part of about 5 mm) as they are more efficient for ....

Results

The presented technique was used to analyze the role of Sin1, one of the core components of the Tor complex 2 (TORC2), in controlling in vivo cell migration. The use of cell transplantation permits labeling of isolated cells and analysis of cell-autonomous effects. Movie S1 shows the migration of transplanted prechordal plate progenitor cells. Actin labeling with ABP140 allows the easy visualization of actin-rich cytoplasmic protrusions. We measured their frequency and orientatio.......

Discussion

This protocol presents an easy way to study the role of a candidate gene in cell migration in vivo, by combining the creation of chimeric embryos using cell transplantation with live imaging.

Creation of mosaic embryos

Studying the dynamics of a cell requires the visualization of its contour to analyze cytoplasmic extensions. This can be achieved by labeling isolated cells in an otherwise unlabeled – or differently labeled - environment, thus off.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Glass capillaries (outside diameter 1.0 mm, inside diameter 0.58 mm)	Harvard Apparatus	300085	standard thickness
Glass capillaries (outside diameter 1.0 mm, inside diameter 0.78 mm)	Harvard Apparatus	300085	thin-walled
Penicillin-Streptomycin	Sigma-Aldrich	P4333	10 000 units penicillin and 10 mg streptomycin per ml
fine tweezers	Dumont Fine Science Tools	11254-20	5F
glass bottom dishes	MatTek	P35G-0-10-C
Air transjector	Eppendorf	5246
Micro-forge	Narishige	MF-900
Microgrinder	Narishige	EG-44
Micromanipulator (for injection)	Narishige	MN-151
Micromanipulator (for cell transplantation)	Leica	Leica Micromanipulator
Hammilton Syringe	Narishige	IM-9B
Micropipette puller	David Kopf Instruments	Model 720
Transplantation mold	Adapative Science Tools	PT-1
Needle holder	Narishige	HI-7
Tube connector	Narishige	CI-1
PTFE tubing	Narishige	CT-1