The insertion of mesenchyme cells into the ectoderm during differentiation in Sea urchin embryos

1992 ◽  
Vol 201 (6) ◽  
pp. 383-388 ◽  
Author(s):  
Evelyn Spiegel ◽  
Melvin Spiegel
Keyword(s):  
Sea Urchin ◽  
Sea Urchin Embryos ◽  
Mesenchyme Cells

Lectin uptake and incorporation into the calcitic spicule of sea urchin embryos

Zygote ◽  
2014 ◽  
Vol 23 (3) ◽  
pp. 467-473 ◽  
Author(s):  
Nancy M. Mozingo
Keyword(s):  
Sea Urchin ◽  
Wheat Germ ◽  
Matrix Proteins ◽  
Fluorescent Label ◽  
Sea Urchin Embryos ◽  
Intracellular Vesicles ◽  
Mesenchyme Cells ◽  
Fluorescent Tag ◽  
Larval Skeleton ◽  
Membranous Material

SummaryPrimary mesenchyme cells (PMCs) are skeletogenenic cells that produce a calcareous endoskeleton in developing sea urchin larvae. The PMCs fuse to form a cavity in which spicule matrix proteins and calcium are secreted forming the mineralized spicule. In this study, living sea urchin embryos were stained with fluorescently conjugated wheat germ agglutinin, a lectin that preferentially binds to PMCs, and the redistribution of this fluorescent tag was examined during sea urchin development. Initially, fluorescence was associated primarily with the surface of PMCs. Subsequently, the fluorescent label redistributed to intracellular vesicles in the PMCs. As the larval skeleton developed, intracellular granular staining diminished and fluorescence appeared in the spicules. Spicules that were cleaned to remove membranous material associated with the surface exhibited bright fluorescence, which indicated that fluorescently labelled lectin had been incorporated into the spicule matrix. The results provide evidence for a cellular pathway in which material is taken up at the cell surface, sequestered in intracellular vesicles and then incorporated into the developing spicule.

Immunogold and immunoblot studies on a cell surface protein found in primary mesenchyme cells and in the cortical secretory vesicles of the sea urchin egg

1987 ◽  
Vol 45 ◽  
pp. 832-833
Author(s):  
G.L. Decker ◽  
M.C. Valdizan
Keyword(s):  
Cell Surface ◽  
Sea Urchin ◽  
Surface Protein ◽  
Egg Cell ◽  
Secretory Vesicles ◽  
Cell Surface Protein ◽  
Surface Complexes ◽  
Mesenchyme Cells ◽  
Lowicryl K4m ◽  
Primary Mesenchyme Cells

A monoclonal antibody designated MAb 1223 has been used to show that primary mesenchyme cells of the sea urchin embryo express a 130-kDa cell surface protein that may be directly involved in Ca2+ uptake required for growth of skeletal spicules. Other studies from this laboratory have shown that the 1223 antigen, although in relatively low abundance, is also expressed on the cell surfaces of unfertilized eggs and on the majority of blastomeres formed prior to differentiation of the primary mesenchyme cells.We have studied the distribution of 1223 antigen in S. purpuratus eggs and embryos and in isolated egg cell surface complexes that contain the cortical secretory vesicles. Specimens were fixed in 1.0% paraformaldehyde and 1.0% glutaraldehyde and embedded in Lowicryl K4M as previously reported. Colloidal gold (8nm diameter) was prepared by the method of Mulpfordt.

Sign in / Sign up

Export Citation Format

Share Document