Premium
Posterior extension of the chick nephric (Wolffian) duct: The role of fibronectin and NCAM polysialic acid
Author(s) -
Bellairs Ruth,
Lear Pamela,
Yamada Kenneth M.,
Rutishauser Urs,
Lash James W.
Publication year - 1995
Publication title -
developmental dynamics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.634
H-Index - 141
eISSN - 1097-0177
pISSN - 1058-8388
DOI - 10.1002/aja.1002020403
Subject(s) - polysialic acid , fibronectin , biology , vitronectin , microbiology and biotechnology , embryo , anatomy , extracellular matrix , mesonephric duct , endocrinology , neural cell adhesion molecule , biochemistry , cell adhesion , cell , kidney
The nephric duct of the chick embryo starts to form at about stage 10 of Hamburger and Hamilton ([1951] J. Morphol. 88:49–92) and extends posteriorly, fusing with the cloaca at about the end of the third day of incubation (HH stage 17). Evidence from the literature suggests that the extension involves active migration of the posterior tip. This investigation concerned some molecules that might control this migration: fibronectin, vitronectin, the β1 integrin receptor, and NCAM polysialic acid. The concentration of fibronectin in the extracellular matrix was found by immunocytochemistry to be negligible at the posterior end of the duct; treatment of the living embryo with GRGDS failed to halt further extension of the duct; SEM examination of embryos treated with the synthetic peptides of fibronectin GRGDS, GRDGS, SDGR, and GRGES, or with vitronectin, revealed negligible morphological effects on the duct. It is concluded that there is yet no evidence that fibronectin is an important factor in duct migration. NCAM polysialic acid had a similar distribution to fibronectin, but treatment of the living embryo with Endo‐N caused cessation of extension of the duct. Endo‐N is an enzyme that specifically degrades PSA without affecting the NCAM polypeptide itself. It is suggested therefore that PSA may play an important role in duct extension. The synthetic peptides of fibronectin each produced distinctive patterns of blebbing on the surfaces of cells in trunk mesoderm, but the duct cells were unaffected. GRGES and SDGR caused blebbing on cells in the somites and the anterior segmental plate, though not on cells in the posterior segmental plate. This suggests that integrin receptors change in the anterior segmental plate as the mesoderm forms somites from somitomeres. © 1995 Wiley‐Liss, Inc.