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Fig. 4. Expression of vimentin in stage-19, -22 and -24 embryos. (Note: the diagram in this and Figs 5, 6, 7 and 8 indicates the optical section planes presented.) In an anterior-dorsal view of a stage-19 embryo stained with RV202 (A) the neural tube (nt) runs vertically down the centre of the embryo and ends with two bulbs that are the nascent optic vesicles (ov). Vimentin-expressing cells line the sides of the neural tube (nv). Individual round or wedge-shaped cells can be identified through the cleared ectoderm and neural tube. There does not appear to be any staining of the optic vesicles themselves. In an anterior view of a stage-22 embryo stained with RV202 (B), the outer lateral margin of the neural tube contains many cells that are darkly stained for vimentin (nv). There is no staining for vimentin in the optic vesicles. Staining of the cement gland (c) is artifactual. Vimentin-positive cells (nv) can be seen in a lateral view of the optic vesicle of a stage-24 embryo stained with 14h7 (C). Dorsal (dor) is left and ventral (ven) is right in C. Dorsal is at the top and ventral is at the bottom in B. Bars in A and B, 100^m; in C, 250um |
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Fig. 5. Vimentin expression in stage 20 and 22 embryos. In a lateral optic section of a stage-22 embryo stained with RV202 (A), vimentin-expressing cells of the anterior neural tube (nv) are more elongate. Somites (s) are beginning to form beneath the anterior neural tube; vimentin staining can be seen on their surfaces in different focal planes. In a transverse physical section through the trunk of a stage-20 embryo stained with 14h7 (B), the cells at the outer margin of the neural tube stain intensely and those on the ventricular surface stain weakly (nv). The stained cells on the outer margin of the neural tube are restricted to the lateral neural tube and are absent from both dorsal and ventral regions, c, cement gland; n, notochord; nt, neural tube, ov, optic vesicle. Bars in A, 150/im; in B, 100 fim. |
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Fig. 6. Vimentin expression in the stage-26 embryo. A lateral optic section of a stage-26 embryo stained with RV202 (A) reveals that vimentin-expressing cells (nv) are present in the neural tube, from the head to the tailbud. Vimentin-expressing somitic mesenchyme (sm) is present on the eight anteriormost trunk somites. Vimentin-expressing mesenchymal cells are found in the head where the branchial arches are forming (hm) as well as below the anterior trunk somites where the pronephros are forming (pm). An oblique frontal/lateral physical section through posterior trunk region of the neural tube and somites of a stage-26 embryo stained with RV202 (B) reveals that the vimentin-expressing cells of the neural tube (nv) become gradually less elongated toward the tail, ant, anterior; pos, posterior; c, cement gland; nt, neural tube; ov, optic vesicle; s, somite. Bars, 350 fim in A and 150/xm in B. |
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Fig. 7. Vimentin expression in the head region of the stage-26 embryo. In a transverse physical section through the head of a stage-26 embryo stained with 14h7 (A), vimentin-expressing head mesenchyme (hm) appears adjacent to the brain and in the region of the mandibular arch (ma). Vimentin-containing processes of cells of the mesencephalon (me) extend in toward the ventricle (nv). Staining in the cement gland is an artifact. In a transverse physical section through an anterior somite of the trunk stained with 14h7 (B), the mesenchyme at the surface of the somites (sm) is expressing vimentin. Vimentin- expressing cells (nv) are present at the margin of the neural tube and have small processes that extend midway to the ventricular surface. There are no vimentin-expressing cells in the ventral region of the neural tube. There appear to be vimentin-expressing mesenchymal cells dorsal to the neural tube (unmarked arrow), c, cement gland; ma, mandibular arch; me, mesencephalon; n, notochord; nt, neural tube; ov, optic vesicle; s, somites. Bars, 50 jxm in both parts. |
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Fig. 8. A & B.
Transverse sections of stage-35 embryos stained for vimentin. In a
transverse section of the head stained with 14h7 (A), vimentin is found in most ofthe head mesenchyme (hm) surrounding the brain, in the meninges (inn), in thecorneal endothelium (ce) and in the mandibular arch (ma). There is also somemesenchyme (em) in the eye. Vimentin is expressed in cells of the mesencephalonand diencephalon (nv). These cells exhibit the characteristic morphology ofmature radial glia, i.e. they are very thin and extend from the margin to the ventricular surface. The staining of the ectoderm is artifactual. A transverse section through an anterior somite of the dorsal trunk (B) reveals that vimentin is expressed in the dorsal fin mesenchyme (dm). Vimentin is also found in the mesenchyme associated with the outer surface of the somites (sm) and in mesoderm below the pronephric ducts (pm). Vimentin-expressing cells are present in the neural tube and extend from the pial to the ventricular surface (nv).....In the area of the embryo ventral to the region illustrated in B (C) are found the lateral body wall and the yolky endoderm ventral to the pronephros. The pronephric rriesoderm is at the top (pm) and below it, between the mesoderm and the endoderm are the vitelline veins (vv) which contain vimentin-expressing mesenchyme. c, cement gland; de, diencephalon; df, dorsal fin; e, eye; me, mesencephalon; n, notochord; nt, neural tube (spinal chord); p, pharynx; pd, pronephric duct; s, somite; vv, vitelline veins. Bars, 50um in A & B, 25um in C. |
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Fig. 8.C Transverse sections of stage-35 embryos stained for vimentin. In the area of the embryo ventral to the region illustrated in B (C) are found the lateral body wall and the yolky endoderm ventral to the pronephros. The pronephric mesoderm is at the top (pm) and below it, between the mesoderm and the endoderm are the vitelline veins (vv) which contain vimentin-expressing mesenchyme. vv, vitelline veins. pm, pronephric ducts. Bar 25 um in C. |
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Fig. 9. Vimentin staining in the stage-35 embryo. In a lateral optic section of stage-35 embryo stained with RV202 (A), vimentin can be found in the neural tube, in the dorsal fin (df) and on the somites (the somitic mesenchyme is mostly out of focus in this picture). Vimentin is expressed in the pronephric mesenchyme (pm) below the first six somites with progressively less mesenchyme below the more posterior somites. The reticulated pattern of the vitelline veins (vv) can be seen throughout the belly around the yolky endoderm. Vimentin-expressing mesenchyme is present on the branchial arches (ba), around the otic vesicle (oi), covering the eye (e) and on the surface of the brain (b). A close-up optical section of the dorsal fin (B) reveals that the morphology of individual dorsal fin mesenchymal cells (dm) can be distinguished by the vimentin staining. In a lateral optical section midway through the embryo (C), vimentin-expressing mesenchyme surrounds the heart in the pericardial cavity (cm). A close lateral optical section of the anterior somites (D) reveals individual, vimentin-expressing mesenchymal (sm) cells. Individual pronephric mesenchymal cells (pin) are visible below the somites. A close lateral view of the region ventral to the anterior somites is shown in D. (E) reveals that the pronephric mesenchyme (pm) expresses vimentin, as do cells of the vitelline veins (vv). b, brain; ba, branchial arch; c, cement gland; df, dorsal fin; e, eye; nt, neural tube; ot, otic vesicle; s, somite; vv, vitelline veins. Bars, 250um in A, 50um in B, 20um in C, 100um in D and 20um in E. |
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Fig. 1. 14h7 and RV202 staining of A6 cells. Methanol-fixed A6 cells were stained with anti- tubulin (A,B), 14h7 (C,D) or RV202 (E,F). In control cells (A,C,E), both 14h7 and RV202 stain an extended filamentous system, distinct from the microtubule system. Cells treated with nocodazole have depolymerized microtubules (B) and collapsed filament systems stained by 14h7 and RV202 (D,F). Cytokeratin filaments remain extended in nocodazole-treated cells (not shown). Bar in A marks 15/zm. |
