title: Extracellular matrix synthesis is required for the movement of sclerotome and neural crest cells on collagen.
abstract: During early embryogenesis cells of several different populations disperse by active cell movement from one location to another. Preexisting extracellular materials are major determinants of these dispersal patterns, but the cells are also able to modify their substrata by synthesizing and secreting extracellular matrix molecules as they move. In order to determine the contribution made by these deposited materials, several tissues from the early chick embryo have been cultured in the presence of inhibitors of extracellular matrix synthesis and secretion. The tissues examined were sclerotome cells from differentiated somites and neural crest cells. For comparison, undifferentiated somites were also cultured. The movement of these cells was compared in type I collagen gel culture and in conventional culture on artificial substrata. Inhibitors of collagen synthesis were used (cis-hydroxy proline and L-azetidine-2-carboxylic acid) in addition to a proteoglycan inhibitor (p-nitrophenyl-xylopyranoside) and a secretion inhibitor (monensin). Results indicate that sclerotome cells require collagen synthesis for movement in a collagen matrix. Reversal of the effects of collagen inhibitors, by proline and type II collagen, suggest that sclerotome cells normally condition the type I matrix in order to move in it. Inhibition of proteoglycan synthesis produced the greatest effect on the movement of neural crest cells regardless of the substratum, confirming an important role for these molecules in the crest migratory routes. The attachment of all cells to collagen was highly sensitive to the presence of monensin, which is known to reduce the deposition of glycosaminoglycans and fibronectin. These results suggest that conditioning of the extracellular matrix by newly synthesized material is required for cell attachment and movement during early development.
authors.affiliation: Department of Physiology, University of Alberta, Edmonton, Canada.
authors.forename: E J
authors.initials: EJ
authors.lastname: Sanders
authors.forename: S
authors.initials: S
authors.lastname: Prasad
authors.forename: E
authors.initials: E
authors.lastname: Cheung
mesh_terms: D000818:Animals; D001842:Bone and Bones / Q000196:embryology* / Q000378:metabolism; D002465:Cell Movement; D002478:Cells, Cultured; D002642:Chick Embryo; D003094:Collagen; D005314:Embryonic and Fetal Development; D005109:Extracellular Matrix / Q000378:metabolism*; D009432:Neural Crest / Q000166:cytology*
chemical_list: D003094:Collagen