Delamination and tyrosine phosphorylation of SUp62 during early embryogenesis of sea urchin

The ingression of primary mesenchyme cells (PMCs) in the sea urchin embryo is initiated with local degradation of the basal lamina at the vegetal plate epithelium (e.g. Katow & Solursh, 1980). The ingressed PMCs encounter pamlin, a cell adhesion protein in the basal lamina (Katow, 1995), which guides PMC migration to a particular embryonic region to form a ring pattern (Katow & Komazaki, 1996; Katow et al, 2000). Thus extracellular matrix (ECM) provides a necessary guidance cue to the migratory cells, and this implicates the occurrence of intracellular signalling to promote not only cell locomotion but also orientation for the migration. Using embryos of the sea urchin, Hemicentrotus pulcherrimus, I report the temporal expression of P35, a PMC surface protein, during the very early stages of PMC ingression that is downregulated with SUp62 protein in the cytoplasm, and tyrosine phosphorylation of SUp62 as a consequence of PMCs encountering pamlin in light of ECM/cell signal transduction.

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Localization and expression of msp130, a primary mesenchyme lineage-specific cell surface protein in the sea urchin embryo

Development ◽

10.1242/dev.101.2.255 ◽

1987 ◽

Vol 101 (2) ◽

pp. 255-265 ◽

Cited By ~ 4

Author(s):

J.A. Anstrom ◽

J.E. Chin ◽

D.S. Leaf ◽

A.L. Parks ◽

R.A. Raff

Keyword(s):

Cell Surface ◽

Sea Urchin ◽

Sea Water ◽

Surface Protein ◽

Specific Cell ◽

Cell Surface Protein ◽

Sea Urchin Embryo ◽

A Cell ◽

Mesenchyme Cells ◽

Primary Mesenchyme Cells

In this report, we use a monoclonal antibody (B2C2) and antibodies against a fusion protein (Leaf et al. 1987) to characterize msp130, a cell surface protein specific to the primary mesenchyme cells of the sea urchin embryo. This protein first appears on the surface of these cells upon ingression into the blastocoel. Immunoelectronmicroscopy shows that msp130 is present in the trans side of the Golgi apparatus and on the extracellular surface of primary mesenchyme cells. Four precursor proteins to msp130 are identified and we show that B2C2 recognizes only the mature form of msp130. We demonstrate that msp130 contains N-linked carbohydrate groups and that the B2C2 epitope is sensitive to endoglycosidase F digestion. Evidence that msp130 is apparently a sulphated glycoprotein is presented. The recognition of the B2C2 epitope of msp130 is disrupted when embryos are cultured in sulphate-free sea water. In addition, two-dimensional immunoblots show that msp130 is an acidic protein that becomes substantially less acidic in the absence of sulphate. We also show that two other independently derived monoclonal antibodies, IG8 (McClay et al. 1983; McClay, Matranga & Wessel, 1985) and 1223 (Carson et al. 1985), recognize msp130, and suggest this protein to be a major cell surface antigen of primary mesenchyme cells.

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In vivo embryonic expression of laminin and its involvement in cell shape change in the sea urchin Sphaerechinus granularis

Development ◽

10.1242/dev.101.4.659 ◽

1987 ◽

Vol 101 (4) ◽

pp. 659-671 ◽

Cited By ~ 1

Author(s):

R.A. McCarthy ◽

M.M. Burger

Keyword(s):

Monoclonal Antibody ◽

Sea Urchin ◽

Basal Lamina ◽

Cell Shape ◽

Shape Change ◽

Cell Shape Change ◽

A Cell ◽

Mesenchyme Cells ◽

Embryonic Epithelium

Laminin, a component of the embryonic sea urchin basal lamina, is recognized by monoclonal antibody BL1 (Mab BL1). Our results demonstrate that laminin is secreted into the blastcoel at the early blastula stage at a time when the blastomeres undergo a cell shape change and are organized into an epithelium. Laminin is present on the basal surfaces of ectodermal cells and is absent or reduced on migrating primary mesenchyme cells. Microinjection of a monoclonal antibody directed against laminin induces a morphological change in cell shape and a deformation of the embryonic epithelium. Investigation of selected stages of live embryos suggests that the distribution of laminin may be heterogeneous within the basal lamina during early development. The results implicate laminin as a mediator of cell shape change during early morphogenesis.

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Pamlin, a Primary Mesenchyme Cell Adhesion Protein, in the Basal Lamina of the Sea Urchin Embryo

Experimental Cell Research ◽

10.1006/excr.1995.1180 ◽

1995 ◽

Vol 218 (2) ◽

pp. 469-478 ◽

Cited By ~ 25

Author(s):

Hideki Katow

Keyword(s):

Cell Adhesion ◽

Sea Urchin ◽

Basal Lamina ◽

Adhesion Protein ◽

Cell Adhesion Protein ◽

Sea Urchin Embryo ◽

Mesenchyme Cell

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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

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100128444 ◽

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.

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Primary mesenchyme cells of the sea urchin embryo require an autonomously produced, nonfibrillar collagen for spiculogenesis

Developmental Biology ◽

10.1016/0012-1606(91)90335-z ◽

1991 ◽

Vol 148 (1) ◽

pp. 261-272 ◽

Cited By ~ 34

Author(s):

Gary M. Wessel ◽

Marc Etkin ◽

Steve Benson

Keyword(s):

Sea Urchin ◽

Sea Urchin Embryo ◽

Mesenchyme Cells ◽

Primary Mesenchyme Cells

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Cell interactions and mesodermal cell fates in the sea urchin embryo

Development ◽

10.1242/dev.116.supplement.43 ◽

1992 ◽

Vol 116 (Supplement) ◽

pp. 43-51 ◽

Cited By ~ 7

Author(s):

Charles A. Ettensohn

Keyword(s):

Sea Urchin ◽

Cell Interactions ◽

Cell Labeling ◽

Cell Fates ◽

Mesodermal Cell ◽

Sea Urchin Embryo ◽

Present Information ◽

Cell Type Specific ◽

Mesenchyme Cells

Cell interactions during gastrulation play a key role in the determination of mesodermal cell fates in the sea urchin embryo. An interaction between primary and secondary mesenchyme cells (PMCs and SMCs, respectively), the two principal populations of mesodermal cells, regulates the expression of SMC fates. PMCs are committed early in cleavage to express a skeletogenic phenotype. During gastrulation, they transmit a signal that suppresses the skeletogenic potential of a subpopulation of SMCs and directs these cells into an alternative developmental pathway. This review summarizes present information concerning the cellular basis of the PMC-SMC interaction, as analyzed by cell transplantation and ablation experiments, fluorescent cell labeling methods and the use of cell type-specific molecular markers. The nature and stability of SMC fate switching, the timing of the PMC-SMC interaction and its quantitative characteristics, and the lineage, numbers and normal fate of the population of skeletogenic SMCs are discussed. Evidence is presented indicating that PMCs and SMCs come into direct filopodial contact during the late gastrula stage, when the signal is transmitted. Finally, evolutionary questions raised by these studies are briefly addressed.

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