Figure 1.
Glial cells in the chick optic nerve are immunoreactive for Nkx2.2, Sox2, Sox9, GFAP and TFBP.
Longitudinal sections through the optic nerve and nerve head were labeled with antibodies to Nkx2.2 (magenta in a, d, f and g; blue in e; green in h and j), Sox2 (red), TFBP (green in c–e and g) and GFAP (grayscale; i and j). Images were obtained by using wide-field epifluoresence microscopy (a–g) or confocal microscopy (h–j). The region indicated by the yellow box in panel d is enlarged 4-fold in panels e–g, and the region in panel j is enlarged 2-fold in the inset. Arrow-heads indicate the nuclei of GFAP/Sox2-positive Müller glia. Small double-arrows indicate TFBP-positive oligodendrocytes in the retina. Arrows indicate Sox2/Nkx2.2-positive nuclei of NIRG cells in the optic nerve and retina. Carets indicate Sox2-positive nuclei of peripapillary glia. Hollow arrow-heads indicate Sox2/Nkx2.2-negative, TFBP-positive oligodendrocytes in the optic nerve. Small double-arrows indicate TFBP-positive oligodendrocytes in the retina. The scale bar (50 µm) in panel d applies to a–d, and the bar in j applies to h–j. Abbreviations: ONL – outer nuclear layer, INL – inner nuclear layer, IPL – inner plexiform layer.
Table 1.
Summary of the glial cell types in the eyes of different vertebrate species.
Table 2.
Summary of immunolabeling of glial cells in the retina and optic nerve of different vertebrate species.
Figure 2.
Glial cells in the mouse retina and optic nerve are immunoreactive for Sox2, Sox9, GFAP, and S100β.
Sections through the retina and optic nerve head were labeled with antibodies to Sox9 (magenta; a–d and h), GFAP (green; a–d and h), Sox2 (magenta; e–g and i), and S100β (green; e–g and i). Hollow arrow-heads indicate the nuclei of Müller glia. Arrows indicate the nuclei of astrocytes. Small double-arrow-heads indicate the nuclei of cholinergic amacrine cells that are labeled for Sox2. Asterisks indicate blood vessels. The scale bar (50 µm) in panel a applies to a alone, the bar in d applies to b–d, the bar in g applies to e–g, and the bar in i applies to i and h. Abbreviations: ONL – outer nuclear layer, INL – inner nuclear layer, IPL – inner plexiform layer, GCL – ganglion cell layer.
Figure 3.
The guinea pig retina does not contain astrocytes or NIRG cells.
Vertical sections of the retina were labeled with antibodies to Islet1 (green; a, b and e), Sox9 (magenta; a, c and e), Sox2 (red; a, d–f and h) and S100β (green; g and h). Arrow-heads indicate the nuclei of Müller glia, small double-arrows indicate the nuclei of bipolar cells that are labeled for Islet1 alone, and the small double-arrow-heads indicate the nuclei of cholinergic amacrine cells that are labeled for Islet1 and Sox2. The scale bar (50 µm) in panel a applies to a alone, the bar in b applies to b–e, and the bar in h applies to g–h. Abbreviations: RPE – retinal pigmented epithelium, PRL – photoreceptor layer, ONL – outer nuclear layer, INL – inner nuclear layer, IPL – inner plexiform layer, GCL – ganglion cell layer.
Figure 4.
Glial cells in the guinea pig optic nerve and nerve head are immunoreactive for Sox2, GFAP, Nkx2.2, Sox9 and S100β.
Longitudinal sections through the optic nerve and nerve head were labeled with antibodies to Sox2 (red in a), GFAP (green in a), Nkx2.2 (green in b and d), Sox9 (red in c,d,f and g) and S100β (green in e and g). Images were obtained by using wide-field epifluoresence microscopy (a) or confocal microscopy (b–g). Arrow-heads indicate the nuclei of Müller glia. The arrows in panels b–d indicate glial cells in the optic nerve that are immunoreactive for Nkx2.2 and Sox9. The arrows in panels e–g indicate glial cells in the optic nerve head that are immunoreactive for S100β and Sox9 The asterisks in panel a indicate a blood vessel. The regions indicated by yellow boxes in panels in b–d are enlarged 2-fold in the in-sets. The transparent blue lines indicate the boundaries between the optic nerve head and neural retina. The scale bar (50 µm) in panel a applies to a alone, the panel in d applies to b–d, and the bar in g applies to e–g. Abbreviations: ONL – outer nuclear layer, INL – inner nuclear layer, IPL – inner plexiform layer, GCL – ganglion cell layer.
Figure 5.
In the dog retina, astrocytes are immunoreactive Sox2, Sox9 and GFAP, whereas NIRG-like cells are immunoreactive Sox2 and Sox9 alone.
Vertical sections of the retina were label with antibodies to Sox9 (green in a,d,e,g and h), Islet1 (magenta in b and d), Sox2 (red in c and d) and GFAP (red in f–h). Panel h includes orthogonal projections to demonstrate that some of the Sox9-positive nuclei in the NFL are not rimmed by GFAP-positive cytoplasm. Arrow-heads indicate the nuclei of Müller glia. Hollow arrow-heads indicate Islet1-positive nuclei of bipolar cells. Small hollow, double arrow-heads indicate the nucleus of cholinergic amacrine cells that is positive for Islet1 and Sox2. Small double-arrows indicate the nuclei of presumptive NIRG-like cells that are positive for Sox9 and Sox2, but negative for GFAP. Arrows indicate GFAP-positive astrocytes that are labeled for Sox9 and Sox2. The scale bar (50 µm) in panel d applies to d and a–d, the bar in g applies to e–g, and the bar in h applies to h alone. Abbreviations: INL – inner nuclear layer, IPL – inner plexiform layer, GCL – ganglion cell layer, NFL – nerve fiber layer.
Figure 6.
In the dog eye, glial cells in the optic nerve and nerve head express the transcription factors Nkx2.2, Sox2 and Sox9.
Longitudinal sections through the optic nerve and nerve head were labeled with antibodies to Nkx2.2 (green), Sox2 (red) and Sox9 (magenta). The area indicated by the yellow box in panel b is enlarged 2.5-fold in panels c–f. White arrows indicate the nuclei of cells labeled for Nkx2.2, Sox 2 and Sox9. Yellow arrows indicate cells labeled for Nkx2.2 and Sox9, but not Sox2. Small double-arrows indicate cells labeled for Sox2 and Sox9, but not Nkx2.2. Solid arrow-heads indicate the nuclei of Müller glia labeled for Sox2 and Sox9. Hollow arrow-heads indicate peripapillary glia labeled for Sox2 and Sox9. The scale bar (50 µm) in panel b applies to a and b, and the bar in f applies to c–f. Abbreviations: ONL – outer nuclear layer, INL – inner nuclear layer, GCL – ganglion cell layer.
Figure 7.
In the monkey eye, Sox2/Sox9-positive glial cells scattered across the GCL and NFL are GFAP+ astrocytes or GFAP− NIRG-like cells.
Vertical sections of the retina were labeled for Islet1 (green in a and d), Sox9 (magenta in b and d; red in e; green in f–l), Sox2 (red in c and d), Brn3a (green in e), GFAP (red in g–l). DRAQ5 (magenta) was used to stain nuclei (h and i). The area indicated by the yellow box in panel i is enlarged 2.5-fold in panels j–l. Small-double arrows indicate the nuclei of Müller glia. Arrows indicate the nuclei of glial cells in the GCL or NFL. Small double arrow-heads indicate Sox9-positive nuclei in the RPE (a–d). Small hollow, double arrow-heads indicate Islet1-positive nuclei of bipolar cells (a–d). Blue arrows indicate Islet1-positive nuclei of ganglion cells (a–d). In panels f–l., arrows indicate GFAP/Sox9-positive astrocytes and hollow arrow-heads indicate GFAP-negative/Sox9-positive NIRG-like cells. Asterisks indicate blood vessels. The scale bar (50 µm) in panel d applies to panels a–d, the bar in e applies to e alone, and the bar in i applies to f–i. Abbreviations: RPE- retinal pigmented epithelium, PRL – photoreceptor layer, ONL – outer nuclear layer, INL – inner nuclear layer, IPL – inner plexiform layer, GCL – ganglion cell layer, NFL – nerve fiber layer.
Figure 8.
In the monkey eye, S100β is expressed by many Müller glia in the retina and glial cells in the optic nerve.
Sections of the retina and optic nerve head were labeled with antibodies to Islet1 (a and d), Sox2 (green in b,d,e and g; red in h–k), S100β (red in c,d,f and g) and nestin (green in h–k). Arrow-heads indicate the nuclei of Müller glia labeled for Sox2 and/or S100β. Blue arrows indicate Sox2/Islet1-positive nuclei of cholinergic amacrine cells (a–d). Small double-arrow-heads indicate the nuclei of Sox2-positive glial cells that are nestin-negative (h–o). Arrows indicate presumptive NIRG-like cells that are labeled for Sox2, nestin and Pax2. Small hollow-double-arrows indicate nuclei labeled for Pax2 and Sox2, but not nestin (l–o). Asterisks indicate blood vessels. The scale bar (50 µm) in panel d applies to a–d, the bar in h applies to e–g and h, and the bar in i applies to f, g and i. Abbreviations: ONL – outer nuclear layer, INL – inner nuclear layer, IPL – inner plexiform layer, GCL – ganglion cell layer, NFL – nerve fiber layer, ONH – optic nerve head.
Figure 9.
In the monkey eye, glial cells in the optic nerve and nerve head express Sox9, Nkx2.2, Sox2, S100β and APC.
Longitudinal and transverse sections through the optic nerve and nerve head were labeled with antibodies to Sox9 (red in a–d; green in e–k and l–p), Nkx2.2 (green in a–d; red q and r), S100β (red in g and h), Sox2 (red in i, k and l–p) and APC (magenta l–p; green q and r). DRAQ5 (magenta) was used to stain nuclei (e and h). Images were obtained using confocal microscopy (a–h and l–r) or wide-field epifluoresence (i–k). The images in panels p and r were generated as 3D shadow-reconstructions of Z-stacks using Zeiss Zen software. The area indicated by the yellow box in panel a is enlarged 4-fold in panels b–d. Arrows indicate glial cells in the optic nerve that are labeled for Nkx2.2 and Sox9 (a–d), Sox9 and S100β (e–h), Sox9 and Sox2 (i–k), Sox2, Sox9 but not APC (l–p), or Nkx2.2 and APC (q and r). Hollow arrow-heads indicate the nuclei of glial cells labeled for Sox9 alone (b–d and i–k), or DRAQ5 alone (e–h). Arrowheads indicate oligodendrocytes labeled for Sox2, Sox9 and APC (l–p) or Nkx2.2 and APC (q and r). Asterisks indicate blood vessels. The scale bar (50 µm) in panel a applies to a alone, the bar in h applies to e–h, the bar in k applies to i–k, the bar l applies to l alone, the bar p applies to m–p alone, the bar in q applies to o alone, the bar in r applies to r alone.