Mackie EJ et al. (1988), The distribution of tenascin coincides with pat...

XB-ART-27812

Development 1988 Jan 01;1021:237-50.

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The distribution of tenascin coincides with pathways of neural crest cell migration.

Mackie EJ , Tucker RP , Halfter W , Chiquet-Ehrismann R , Epperlein HH .

Abstract
The distribution of the extracellular matrix (ECM) glycoprotein, tenascin, has been compared with that of fibronectin in neural crest migration pathways of Xenopus laevis, quail and rat embryos. In all species studied, the distribution of tenascin, examined by immunohistochemistry, was more closely correlated with pathways of migration than that of fibronectin, which is known to be important for neural crest migration. In Xenopus laevis embryos, anti-tenascin stained the dorsal fin matrix and ECM along the ventral route of migration, but not the ECM found laterally between the ectoderma and somites where neural crest cells do not migrate. In quail embryos, the appearance of tenascin in neural crest pathways was well correlated with the anterior-to-posterior wave of migration. The distribution of tenascin within somites was compared with that of the neural crest marker, HNK-1, in quail embryos. In the dorsal halves of quail somites which contained migrating neural crest cells, the predominant tenascin staining was in the anterior halves of the somites, codistributed with the migrating cells. In rat embryos, tenascin was detectable in the somites only in the anterior halves. Tenascin was not detectable in the matrix of cultured quail neural crest cells, but was in the matrix surrounding somite and notochord cells in vitro. Neural crest cells cultured on a substratum of tenascin did not spread and were rounded. We propose that tenascin is an important factor controlling neural crest morphogenesis, perhaps by modifying the interaction of neural crest cells with fibronectin.

PubMed ID: 2458221

Species referenced: Xenopus laevis
Genes referenced: b3gat1l fn1 tnc

Article Images: [+] show captions

	Fig. 1. Immunohistochemical staining of cross-sections through the anterior trunk of Xenopus laevis embryos with antibodies to tenascin (77V) and fibronectin (FN). (A) Anti-tenascin staining is limited to the matrix of the dorsal fin (df) and the intersomitic furrows (if) in stage 25/26 embryos. The neural crest (large arrow) is still found along the dorsal surface of the neural tube (ni) at this stage. No anti-tenascin staining is seen between the ectoderm and the somites (s, small arrows), nch, notochord; en, endoderm. (B) Anti-fibronectin stains the ECM throughout the stage 25/26 embryo. (C) At stage 32, when neural crest cells are found in the dorsal fin and along the ventral pathway (along the medial surface of the somites, arrows), anti-tenascin stains the ECM of the dorsal fin, intersomitic furrows and ventral pathway. (D) Anti-fibronectin stains the ECM throughout the embryo, including the matrix underlying the ectoderm where the neural crest cells are not found.
	Fig. 2. Anti-tenascin (77V) and anti-fibronectin (FN) staining of cross-sections through different axial levels of a 54h-old quail embryo. (A) In the anterior trunk, where neural crest cells have begun to migrate, anti-tenascin stains the ECM surrounding the neural tube (nt), notochord and somites (s). Anti-tenascin staining is seen only in the embryo and not in extraembryonic membranes (arrow). (B) In an adjacent section, anti-fibronectin stains the ECM throughout the embryo and the extraembryonic membranes (arrow). (C) At an axial level posterior to (i.e. preceding) neural crest cell migration, anti-tenascin staining is very faint in the embryo and is not seen in extraembryonic membranes (arrow). (D) In contrast to the staining with anti-tenascin, anti-fibronectin stains the ECM throughout the embryo and extraembryonic membranes (arrow) in a section adjacent to that shown in C. (E) At an axial level posterior to that shown in C and D, anti-tenascin stains cells at the ingressing margin of Hensen's node (arrow), but elsewhere in the embryo anti-tenascin staining is very faint. (F) Anti-fibronectin intensely stains ECM in a section (adjacent to that shown in E) through Hensen's node.
	Fig. 3. Frontal sections through the somites in the midtrunk region of quail embryos, stained with antitenascin (TN), anti-fibronectin {FN) and antibody to the neural crest marker, HNK-1 (NC). (A-I) Serial 14/un sections through somites 9-18 of a quail embryo of about 30 somites. The section in A is dorsal to that in I. The sections are not exactly frontal, but rather slightly diagonal from side to side so that the section in A shows the most ventral part of the somites at the bottom of the field and the most dorsal part of the somites at the top of the field. The embryo is also slightly curved dorsoventrally, so that the somites in the middle of the field are cut through a more ventral part than the somites at the two ends in any particular section. In all sections, tenascin is present in the intersomitic furrows and outlining the neural tube (nt), as well as around the notochord (nch). In the dorsal halves of the somites, staining with anti-tenascin is much more intense in the anterior (a) halves than in the posterior (p) halves. Moving more ventrally within a particular somite the staining becomes more even anteroposteriorly. (J) A higher magnification of the somites outlined in D. dm, dermamyotome; a, anterior;/?, posterior. (K,L) A single section of somites 14 and 15 from a quail embryo of about 30 somites, stained with anti-tenascin (K) and anti-HNK-1 (L) shows codistribution of tenascin and neural crest cells in the anterior (left) half of each somite. (M,N) In two sections adjacent to that in K and L, fibronectin (N) is evenly distributed within the somites, whereas tenascin (M) is almost entirely restricted to the anterior (left) half.
	Fig. 4. Cross-sections through the anterior trunk of a 10-5-day-old rat embryo stained with anti-tenascin (77V) and anti-fibronectin (FN). (A) In a section through the anterior part of the somite, cells in the lateral portion of the sclerotome (s) are stained with anti-tenascin. Small arrows at the top and bottom of the figure indicate the plane of the sections shown in Fig. 5E and F. dm, dermamyotome; nt, neural tube. (B) In an adjacent section anti-fibronectin stains the ECM surrounding the neural tube and dermamyotome, as well as the entire sclerotome. (C) Sections near the intersomitic furrows show anti-tenascin staining along the basal lamina adjacent to the dermamyotome (large arrow). Small arrows at the right and left sides of the figure indicate the approximate plane and level of the sections shown in Fig. 5A,B (upper arrows) and Fig. 5C,D (lower arrows). (D) As seen in B, anti-fibronectin stains the ECM throughout the somite in a section adjacent to that shown in C. Fluorescence within the neural tube and dermamyotome in A and C is due to background, as demonstrated by sections stained with preimmune serum (not shown).
	Fig. 5. Frontal and sagittal sections through the somites of a 10-5-day-old rat embryo stained with antibodies to tenascin (TN) and fibronectin (FN). See small arrows in Fig. 4 for orientation. (A) In frontal sections through the dorsal part of the somites, anti-tenascin stains the intersomitic furrows adjacent to the dermamyotome (arrow) intensely. dm, dermamyotome; nt, neural tube; s, sclerotome. (B) Anti-fibronectin staining of a section adjacent to the section shown in A shows intense labelling of ECM surrounding the dermamyotome and throughout the sclerotome. (C) In frontal sections through the midlevel of the somite, anti-tenascin staining is most intense in the anterior half of each somite, between the dermamyotome and the sclerotome (arrows). The intersomitic furrows are indicated by a dashed line, a, anterior; p, posterior. (D) Again, in a section adjacent to that shown in C, anti-fibronectin stains both the anterior and posterior halves of the somite with equal intensity, as well as the ECM surrounding the neural tube and underlying the ectoderm. (E) In sagittal sections through the somites, anti-tenascin staining in the anterior half of each somite but not in the posterior half is clear. An intersomitic furrow is indicated by the dashed line, a, anterior; p, posterior. (F) In contrast to the anti-tenascin staining, anti-fibronectin stains both the anterior (a) and posterior (p) halves of the somites in a section adjacent to that shown in E. Fluorescence within the neural tube and dermamyotome in A and C is due to background, as demonstrated by sections stained with preimmune serum (not shown).
	Fig. 6. Immunocytochemical staining of primary cultures of quail neural crest cells, somite cells and notochord cells with antibodies to tenascin (77V) and fibronectin (FN) 48 h after explantation. No staining with either anti-tenascin (A) or anti-fibronectin (B) is seen in neural crest cell cultures. Anti-tenascin stains matrix deposited by somite cells (C) and notochord cells (E). Similar fibrillar matrix staining is seen when antibodies to fibronectin are used to stain somite cells (D) and notochord cells (F).
	Fig. 7. 24h-old primary cultures of quail neural crest cells on tissue culture plastic uncoated (TC) or coated with tenascin (TN), fibronectin (FN) or laminin (LN). All cultures were grown in defined medium without serum. (A) Neural crest cells on tenascin-coated plastic spread from the neural tube (at the left). The cells are rounded, and blebs are commonly seen. (B) Neural crest cells cultured on fibronectin-coated substrata are typically flattened, with large lamellipodia. (C) Neural crest cells cultured on uncoated tissue culture plastic are not as flattened as those on fibronectin, but they appear to be more strongly attached to the substratum than cells on tenascin. (D) Neural crest cells cultured on laminin-coated substrata have a saucer-like morphology, distinct from the morphologies of cells cultured on the other substrata.