The drawing below is a zebrafish embryo just 3 days after egg fertilisation. The head is to the left and the tail is to the right (only 4mm long). We can study the rapid development of these small embryos by direct live observation due to their inherent transparency. The box indicates a small area of the spinal cord.
The image below the drawing is of a cell called an oligodendrocyte, which is responsible for making the myelin sheaths, the long thin structures. Myelin sheaths surround the nerve cell processes in our brains and spinal cords and allow rapid nerve propagation and maintain nerve health. It is a great advantage of zebrafish to be able to see and monitor such cells in the living animal over time without the need for any surgery.
We use zebrafish to study nervous system development. Our current focus is on elucidating mechanisms that orchestrate the formation of myelinated axons. Myelinated axons are essential for normal nervous system development and function, and disruption of the myelin sheath and associated axons is associated with many human diseases including Multiple Sclerosis (MS).
Our lab uses zebrafish for two principle reasons: their amenability for live cell imaging and high-resolution cellular analyses, and their ability to be used to carry out large-scale genetic and chemical screens.
Zebrafish embryos are transparent and undergo rapid early development (myelin is formed from just two days after egg fertilization). These facts coupled with the relative simplicity of the early nervous system and the availability of transgenic lines that drive fluorescent reporters in a variety of cell types, make the zebrafish ideal for live in vivo imaging of entire developmental processes. We are currently using these approaches to study cell behaviour and cell-cell interactions during central nervous system myelination in vivo (see publications). We are also conducting a gene discovery screen to identify the molecular basis myelination by in vivo. We also carry out chemical compound screens as an additional approach to identify the molecular basis of myelination, and as part of collaborative drug discovery projects.
- Professor Peter Brophy (CNR, University of Edinburgh)
- Professor Charles ffrench Constant (CRM, University of Edinburgh)
- Prof. Robin Franklin (Cambridge University)
- Prof. Mikael Simons (Max Planck Institute, Goettingen)
- Professor William Talbot (Stanford University)
- Dr. Claire Wyart (ICM, Paris) Biogen Idec (Cambridge, MA, USA)