Characterization of myelination in the developing zebrafish
- 8 May 2002
- Vol. 39 (1), 47-57
- https://doi.org/10.1002/glia.10088
Abstract
Myelination, the process by which glial cells ensheath and electrically insulate axons, has been investigated intensely. Nevertheless, knowledge of how myelination is regulated or how myelinating cells communicate with neurons is still incomplete. As a prelude to genetic analyses of these processes, we have identified zebrafish orthologues of genes encoding major myelin proteins and have characterized myelination in the larval zebrafish. Expression of genes corresponding to proteolipid protein (PLP/DM20), myelin protein zero (P0), and myelin basic protein (MBP) is detected at 2 days postfertilization (dpf), first in the ventral hindbrain, close to the midline. During the next 8 days, expression spreads rostrally to the midbrain and optic nerve, and caudally to the spinal cord. DM20 is expressed in the CNS only, while MBP transcripts are detected both in the CNS and in Schwann cells of the lateral line, cranial nerves, and spinal motor nerves. Unlike its closest homologue, trout IP1, zebrafish P0 transcripts were restricted to the CNS. Ultrastructurally, the expression of myelin genes correlated well with myelination, although myelination showed a temporal lag. Myelinated axons were first detected at 4 dpf in the ventral hindbrain, where they were loosely wrapped by processes of glia cells. By 7 dpf, bundles of heavily myelinated axons were observed in the same region. Axons in the lateral line and optic nerves were also surrounded by compact myelin. Conservation in gene expression patterns and the early appearance of myelinated axons, support using the zebrafish to dissect the process of myelination by a genetic approach. GLIA 39:47–57, 2002.Keywords
This publication has 46 references indexed in Scilit:
- Comparative genomics provides evidence for an ancient genome duplication event in fishPhilosophical Transactions Of The Royal Society B-Biological Sciences, 2001
- Structure, heterologous expression, and adhesive properties of the P0‐like myelin glycoprotein IP1 of trout CNSMicroscopy Research and Technique, 2001
- Glial inhibition of nerve regeneration in the mature mammalian CNSGlia, 1999
- Molecular Evolution of Myelin Proteolipid ProteinBiochemical and Biophysical Research Communications, 1997
- Molecular Cloning and Tissue Expression of a cDNA Encoding IP1—A P0‐Like Glycoprotein of Trout CNS MyelinJournal of Neurochemistry, 1995
- Characterization of Basic Proteins from Goldfish MyelinJournal of Neurochemistry, 1993
- Protein zero of peripheral nerve myelin: Biosynthesis, membrane insertion, and evidence for homotypic interactionNeuron, 1990
- Human myelin DM-20 proteolipid protein deletion defined by cDNA sequenceBiochemical and Biophysical Research Communications, 1987
- Expression of a myelin basic protein gene in transgenic shiverer mice: Correction of the dysmyelinating phenotypeCell, 1987
- A Morphological and Biochemical Study of Myelinogenesis in Fish BrainDevelopmental Neuroscience, 1981