Developmental characterization of the gene for laminin alpha-chain in sea urchin embryos

Mech Dev. 1999 Mar;81(1-2):37-49. doi: 10.1016/s0925-4773(98)00222-6.


We describe the isolation and characterization of a cDNA clone encoding a region of the carboxy terminal globular domain (G domain) of the alpha-1 chain of laminin from the sea urchin, Strongylocentrotus purpuratus. Sequence analysis indicates that the 1.3 kb cDNA (spLAM-alpha) encodes the complete G2 and G3 subdomains of sea urchin a-laminin. The 11 kb spLAM-alpha mRNA is present in the egg and declines slightly in abundance during development to the pluteus larva. The spLAM-alpha gene is also expressed in a variety of adult tissues. Whole mount in situ hybridization of gastrula stage embryos indicates that ectodermal and endodermal epithelia and mesenchyme cells contain the spLAM-alpha mRNA. Immunoprecipitation experiments using an antibody made to a recombinant fusion protein indicates spLAM-alpha protein is synthesized continuously from fertilization as a 420 kDa protein which accumulates from low levels in the egg to elevated levels in the pluteus larva. Light and electron microscopy identify spLAM-alpha as a component of the basal lamina. Blastocoelic microinjection of an antibody to recombinant spLAM-alpha perturbs gastrulation and skeleton formation by primary mesenchyme cells suggesting an important role for laminin in endodermal and mesodermal morphogenesis.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Basement Membrane / ultrastructure
  • Blotting, Northern
  • Bone and Bones / embryology
  • DNA, Complementary / metabolism
  • Gastrula / metabolism
  • Gastrula / pathology
  • Gene Library
  • Immunoblotting
  • In Situ Hybridization
  • Laminin / genetics*
  • Laminin / metabolism
  • Microinjections
  • Microscopy, Confocal
  • Microscopy, Fluorescence
  • Microscopy, Immunoelectron
  • Precipitin Tests
  • Sea Urchins / embryology*
  • Sequence Homology, Amino Acid
  • Time Factors
  • Tissue Distribution


  • DNA, Complementary
  • Laminin
  • laminin alpha5

Associated data

  • GENBANK/U65432