Article

Kirby, B.B. et al. In vivo time-lapse imaging shows dynamic oligodendrocyte progenitor behavior during zebrafish development. Nat. Neurosci. 9, 1506-1511

Department of Biological Sciences, Vanderbilt University, 465 21st Avenue South, Nashville, Tennessee 37232, USA.
Nature Neuroscience (Impact Factor: 16.1). 01/2007; 9(12):1506-11. DOI: 10.1038/nn1803
Source: PubMed

ABSTRACT

Myelinating oligodendrocytes arise from migratory and proliferative oligodendrocyte progenitor cells (OPCs). Complete myelination requires that oligodendrocytes be uniformly distributed and form numerous, periodically spaced membrane sheaths along the entire length of target axons. Mechanisms that determine spacing of oligodendrocytes and their myelinating processes are not known. Using in vivo time-lapse confocal microscopy, we show that zebrafish OPCs continuously extend and retract numerous filopodium-like processes as they migrate and settle into their final positions. Process remodeling and migration paths are highly variable and seem to be influenced by contact with neighboring OPCs. After laser ablation of oligodendrocyte-lineage cells, nearby OPCs divide more frequently, orient processes toward the ablated cells and migrate to fill the unoccupied space. Thus, process activity before axon wrapping might serve as a surveillance mechanism by which OPCs determine the presence or absence of nearby oligodendrocyte-lineage cells, facilitating uniform spacing of oligodendrocytes and complete myelination.

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    • "Zebrafish were maintained and bred as described (Westerfield, 1993) and all procedures approved by the University of Utah Institutional Animal Care and Use Committee (IACUC#15- 10011). The Tg(sox10:mRFP) transgenic line was described previously (Kirby et al., 2006). The 3042bp proximal snai1b promoter immediately adjacent to the start ATG codon was amplified Disease Models & Mechanisms @BULLET DMM @BULLET Advance article by standard PCR with primers containing BamH1 (5') and EcoR1 (3') restriction enzyme sites. "
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    • "The TeNT transgenic fish described above provide an excellent opportunity to examine this question. Earlier studies using the sox10:RFP reporter line (Kirby et al., 2006) demonstrated that OPC exhibit highly motile processes during the time-frame spanning OPC specification to the initiation of axon wrapping (approximately 36e72 h post fertilization (hpf)). The study by Hines et al. (2015) "
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    • "Second, only axons above a certain diameter are myelinated (Waxman and Bennett, 1972), and third, recent data suggest that internodes are not evenly spaced throughout the length of the axon (Tomassy et al., 2014). Live imaging in zebrafish has shown that oligodendrocytes go through a dynamic period of process extensions and retractions prior to the final selection of the axons to be myelinated (Kirby et al., 2006). However, following the initial wrapping of the oligodendrocyte processes around the axon, very few retractions are observed (Czopka et al., 2013), suggesting the existence of a narrow time window in which the axons are selected. "
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