Similarities and differences between fish oligodendrocytes and schwann cells in vitro

Abstract

In light of the striking differences between oligodendrocytes of the optic nervdtract of adult goldfish and their mammalian counterparts, a further characterization of goldfish oligodendrocytes was performed. A comparison with Schwann cells was included because fish optic nerveltract-derived oligodendrocytes bear remarkable similarities to this type of glial cell. Fish optic nerveltract-derived oligodendrocytes that had differentiated into 04 and 6D2-positive cells and thus expressed early myelin marker molecules were found to incorporate BrdU and to divide in vitro over a period of weeks. For the induction of more advanced markers of myelinogenesis such as the CNS-specific myelin protein 36K, oligodendrocytes required extensive contact with axons. Other agents, such as fetal calf or carp serum, substrate components, or forscolin failed, however, to induce 36K expression. 0416D2-positive oligodendrocytes could be distinguished from fish 6D2-positive Schwann cells derived from cranial nerves by their antigenic phenotype: Schwann cells but not oligodendrocytes exhibited the low affinity NGF receptor. While both cell types carry the cell adhesion molecules NCAM, E 587 antigen, and the L2/HNK-1 epitope, only Schwann cells possess a further adhesion molecule, Neurolin.

Increased expression of specific recognition molecules by retinal ganglion cells and by optic pathway glia accompanies the successful regeneration of retinal axons in adult zebrafish

“…2. There is evidence from cell culture studies that oligodendrocyte-like cells isolated from goldfish optic nerve can express both an L1-related antigen and N-CAM (Bastmeyer et al, 1994; see also Stuermer et al, 1992). Our data suggest that the observation by Bastmeyer and colleagues is significant also in vivo.…”

“…Axonal regeneration in the CNS is likely to depend not only on the absence of inhibitors in the environment but also on the expression of molecules that are capable of supporting axonal outgrowth (reviewed by Stuermer et al, 1992;Bahr and Bonhoeffer, 1994; see also Blaugrund et al, 1990;Bastmeyer et al, 1994;Battisti et al, 1995;Schwalb et al, 1995). Therefore, the demonstration of up-regulation of the expression levels of 11.1, 11.2, n-cam, and beta3 mRNAs in the lesioned optic pathway of the zebrafish is of particular interest.…”

Characterization of peripheral myelin protein 22 in zebrafish (zPMP22) suggests an early role in the development of the peripheral nervous system

“…We performed in situ hybridization on wholemount preparations of cranial nerves from adult zebrafish, a nerve that is myelinated by Schwann cells (Bastmeyer et al, 1994;Levavasseur et al, 1998). The pattern of in situ labeling was similar to the staining observed for PMP22 in mammalian peripheral nerves (Baechner et al, 1995).…”

Supernumerary neuromasts in the posterior lateral line of zebrafish lacking peripheral glia

“…The absence of sox10 leads to deficient pigmentation and defective development of peripheral glia in the zebrafish, but does not affect the development of sensory axons innervating the lateral line (14,17). We used the monoclonal antibody 6D2, which recognizes a carbohydrate epitope of the piscine P 0 -like myelin glycoproteins IP1 and IP2 (22,23), to confirm that glial cells are absent along the horizontal myoseptum in both cls (Fig. 4 G and H) and ngn1 mutant larvae (Fig.…”