Major isoform of zebrafish P0 is a 23.5 kDa myelin glycoprotein expressed in selected white matter tracts of the central nervous system

Bai, Q., Sun, M., Stolz, D.B., and Burton, E.A.
The Journal of comparative neurology   519(8): 1580-1596 (Journal)
Registered Authors
Burton, Edward A., Sun, Ming
mpz, P0, zebrafish, myelin, oliodendrocyte, tectum, optic nerve, olfactory tract, tectobulbar tract, glycosylation, immunoglobulin domain
MeSH Terms
  • Amino Acid Sequence
  • Animals
  • Central Nervous System/anatomy & histology
  • Central Nervous System/metabolism*
  • Gene Expression Regulation, Developmental
  • Humans
  • Molecular Sequence Data
  • Myelin P0 Protein/genetics
  • Myelin P0 Protein/metabolism*
  • Protein Isoforms/genetics
  • Protein Isoforms/metabolism*
  • Sequence Alignment
  • Zebrafish/anatomy & histology*
  • Zebrafish/metabolism*
  • Zebrafish Proteins/genetics
  • Zebrafish Proteins/metabolism*
21452240 Full text @ J. Comp. Neurol.
The zebrafish mpz gene, encoding the ortholog of mammalian myelin protein zero, is expressed in oligodendrocytes of the zebrafish central nervous system (CNS). The putative gene product, P0, has been implicated in promoting axonal regeneration in addition to its proposed structural functions in compact myelin. We raised novel zebrafish P0-specific antibodies and established that P0 is a 23.5 kDa glycoprotein containing a 3 kDa N-linked carbohydrate moiety. P0 was localized to myelin sheaths surrounding axons, but was not detected in the cell bodies or proximal processes of oligodendrocytes. Many white matter tracts in the adult zebrafish CNS were robustly immunoreactive for P0, including afferent visual and olfactory pathways, commissural and longitudinal tracts of the brain, and selected ascending and descending tracts of the spinal cord. P0 was first detected during development in premyelinating oligodendrocytes of the ventral hindbrain at 48 hours postfertilization (hpf). By 72 hpf, short segments of longitudinally oriented P0-immunoreactive myelinating axons were seen in the hindbrain; expression in the spinal cord, optic pathways, hindbrain commissures, midbrain, and peripheral nervous system followed. The mpz transcript was found to be alternatively spliced, giving rise to P0 isoforms with alternative C-termini. The 23.5 kDa isoform was most abundant in the CNS, but other isoforms predominated in the myelin sheath surrounding the Mauthner axon. These data provide a detailed account of P0 expression and demonstrate novel P0 isoforms, which may have discrete functional properties. The restriction of P0 immunoreactivity to myelin sheaths indicates that the protein is subject to stringent intracellular compartmentalization, which likely occurs through posttranslational mechanisms.
Genes / Markers
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Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Engineered Foreign Genes