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Nodal signal is required for morphogenetic movements of epiblast layer in the pre‐streak chick blastoderm
Author(s) -
Yanagawa Nariaki,
Sakabe Masahide,
Sakata Hirokazu,
Yamagishi Toshiyuki,
Nakajima Yuji
Publication year - 2011
Publication title -
development, growth and differentiation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.864
H-Index - 66
eISSN - 1440-169X
pISSN - 0012-1592
DOI - 10.1111/j.1440-169x.2010.01244.x
Subject(s) - epiblast , primitive streak , blastoderm , microbiology and biotechnology , biology , nodal , gastrulation , nodal signaling , anatomy , morphogenesis , embryo , embryogenesis , genetics , gene
During axis formation in amniotes, posterior and lateral epiblast cells in the area pellucida undergo a counter‐rotating movement along the midline to form primitive streak (Polonaise movements). Using chick blastoderms, we investigated the signaling involved in this cellular movement in epithelial‐epiblast. In cultured posterior blastoderm explants from stage X to XI embryos, either Lefty1 or Cerberus‐S inhibited initial migration of the explants on chamber slides. In vivo analysis showed that inhibition of Nodal signaling by Lefty1 affected the movement of DiI‐marked epiblast cells prior to the formation of primitive streak. In Lefty1‐treated embryos without a primitive streak, Brachyury expression showed a patchy distribution. However, SU5402 did not affect the movement of DiI‐marked epiblast cells. Multi‐cellular rosette, which is thought to be involved in epithelial morphogenesis, was found predominantly in the posterior half of the epiblast, and Lefty1 inhibited the formation of rosettes. Three‐dimensional reconstruction showed two types of rosette, one with a protruding cell, the other with a ventral hollow. Our results suggest that Nodal signaling may have a pivotal role in the morphogenetic movements of epithelial epiblast including Polonaise movements and formation of multi‐cellular rosette.