Identification of genes expressed by zebrafish oligodendrocytes using a differential microarray screen

Abstract

Myelination of central nervous system axons requires that oligodendrocytes extend multiple membrane processes that specifically recognize and wrap axons, which is followed by expression of proteins necessary for formation of myelin sheaths. To identify new genes that might be important for myelination, we used microarrays to analyze the expression profiles of cells sorted from transgenic zebrafish embryos and larvae under conditions that permitted or blocked oligodendrocyte development. Here, we describe eight genes that have not been previously implicated in oligodendrocyte development. Among the predicted functions of proteins encoded by these genes are lipid sensing, cell-cell junction formation, cytoskeleton regulation, and intracellular signaling. The predicted functions raise the possibility that these genes are involved in multiple cellular events during oligodendrocyte differentiation and myelin formation.

Zebrafish as a Model for Monocarboxyl Transporter 8-Deficiency

“…The location and shape of these cells was similar to SOX10-positive oligodendrocyte; the myelin-forming cells (36,37). These results suggest that MCT8 transports THs from the blood vessels into oligodendrocytes and neurons, and regulates myelination and neuron development.…”

“…In addition, mct8 expression was observed in oval cell bodies with short projections that did not express both HUC and GFAP markers. Because the structure and the location of these cells are similar to sox10 expressing cells (36,37), they are likely to be oligodendrocytes. Similarly, in mammals, mct8 mRNA and protein were present in oligodendroglial cells derived from mice (50).…”

Individual axons regulate the myelinating potential of single oligodendrocytes in vivo

“…Here, we use zebrafish, which have recently become established as a powerful model for the study of glial cells and myelinated axons (Brosamle and Halpern, 2002;Buckley et al, 2010;Kazakova et al, 2006;Kirby et al, 2006;Li et al, 2007;Lyons et al, 2009;Monk et al, 2009;Pogoda et al, 2006;Takada and Appel, 2010), to study the role that axons play in regulating CNS myelination in vivo. As is the case in mammals, we show that single oligodendrocytes in zebrafish myelinate either a small number of large caliber axons or a larger number of smaller axons.…”

A Dicer-miR-107 Interaction Regulates Biogenesis of Specific miRNAs Crucial for Neurogenesis

“…Neurospheres formed mainly from the proliferation of GFAP + radial glia cells that served as neural progenitors able to self-renew and differentiate after withdrawal of growth factors for three consecutive culture passages ( Figure S3E, arrowhead; data not shown). After 4 days in vitro in the absence of growth factors (Div4d), zebrafish neurospheres differentiated into all neural cell types: astrocytelike cells (GFAP + ) (Nielsen and Jørgensen, 2003), oligodendrocytes (Sox-10 + ) (Takada and Appel, 2010), and mature neurons (a-tubulin + ) (Ulrich et al, 2011) and expressed gene markers of several postmitotic neural cells (Figures S3F, arrowheads, and S3G). qRT-PCR analysis indicated that, during the course of neurosphere differentiation, dicer mRNA levels progressively declined, while miR-107 expression increased ( Figures 5A and 5B).…”