A fate map of the vegetal plate of the sea urchin (Lytechinus variegatus) mesenchyme blastula.

Previous lineage tracing experiments have shown that the vegetal blastomers of cleavage stage embryos give rise to all the mesoderm and endoderm of the sea urchin larva. In these studies, vegetal blastomers were labeled no later than the sixth cleavage division (60-64 cell stage). In an earlier study we showed that single cells in the vegetal plate of the blastula stage Lytechinus variegatus embryo could be labeled in situ with the fluorescent, lipophilic dye, DiI(C18), and that cells labeled in the central region of the vegetal plate of the mesenchyme blastula primarily gave rise to homogeneous clones consisting of a single secondary mesenchyme cell (SMC) type (Ruffins and Ettensohn (1993) Dev. Biol. 160, 285-288). Our clonal labeling showed that a detailed fate map could be generated using the DiI(C18) labeling technique. Such a fate map could provide information about the spatial relationships between the precursors of specific mesodermal and endodermal cell types and information concerning the movements of these cells during gastrulation and later embryogenesis. We have used this method to construct the first detailed fate map of the vegetal plate of the sea urchin embryo. Ours is a latitudinal map; mapping from the plate center, where the mesodermal precursors reside, through the region which contains the endodermal precursors and across the ectodermal boundary. We found that the precursors of certain SMC types are segregated in the mesenchyme blastula stage vegetal plate and that prospective germ layers reside within specific boundaries. To determine whether the vegetal plate is radially symmetrical with respect to mesodermal cell fates, single blastomeres of four cell stage embryos were injected with lysyl-rhodamine dextran (LRD). The resulting ectodermal labeling patterns were classified and correlated with the SMC types labeled. This analysis indicates that the dorsal and ventral blastomers do not contribute equally to SMC derivatives in L. variegatus.

[1]  C. Ettensohn Primary Invagination of the Vegetal Plate During Sea Urchin Gastrulation , 1984 .

[2]  C. Ettensohn,et al.  Gastrulation in the sea urchin embryo is accompanied by the rearrangement of invaginating epithelial cells. , 1985, Developmental biology.

[3]  S. Ruffins,et al.  Mesodermal cell interactions in the sea urchin embryo: properties of skeletogenic secondary mesenchyme cells. , 1993, Development.

[4]  J. Pehrson,et al.  The fate of the small micromeres in sea urchin development. , 1986, Developmental biology.

[5]  Louis Y. Cheng,et al.  The mechanisms and mechanics of archenteron elongation during sea urchin gastrulation , 1986 .

[6]  R. Burke,et al.  The origin of pigment cells in embryos of the sea urchin Strongylocentrotus purpuratus. , 1985, Developmental biology.

[7]  D. McClay,et al.  The establishment of bilateral asymmetry in sea urchin embryos , 1994 .

[8]  W. Lennarz,et al.  Gastrulation in the sea urchin is accompanied by the accumulation of an endoderm-specific mRNA. , 1989, Developmental biology.

[9]  R. Raff,et al.  Early inductive interactions are involved in restricting cell fates of mesomeres in sea urchin embryos. , 1989, Developmental biology.

[10]  C. Nislow,et al.  Regionalized Cell Division during Sea Urchin Gastrulation Contributes to Archenteron Formation and Is Correlated with the Establishment of Larval Symmetry , 1988, Development, growth & differentiation.

[11]  D. McClay,et al.  Sequential expression of germ-layer specific molecules in the sea urchin embryo. , 1985, Developmental biology.

[12]  G. Merlino,et al.  Effects of deciliation of tubulin messenger RNA activity in sea urchin embryos. , 1978, The Journal of biological chemistry.

[13]  D. McClay,et al.  The origin of spicule-forming cells in a 'primitive' sea urchin (Eucidaris tribuloides) which appears to lack primary mesenchyme cells. , 1988, Development.

[14]  F. Wilt,et al.  Interactions of different vegetal cells with mesomeres during early stages of sea urchin development. , 1991, Development.

[15]  E. Davidson Lineage-specific gene expression and the regulative capacities of the sea urchin embryo: a proposed mechanism. , 1989, Development.

[16]  D. McClay,et al.  Cell lineage conversion in the sea urchin embryo. , 1988, Developmental biology.

[17]  J. Hardin,et al.  Local shifts in position and polarized motility drive cell rearrangement during sea urchin gastrulation. , 1989, Developmental biology.

[18]  R. Britten,et al.  Macromere cell fates during sea urchin development. , 1991, Development.

[19]  C. Ettensohn,et al.  Mechanisms of Epithelial Invagination , 1985, The Quarterly Review of Biology.

[20]  H. Katow,et al.  Ultrastructure of primary mesenchyme cell ingression in the sea urchin Lytechinus pictus , 1980 .

[21]  K. Dan,et al.  Study of the Lineage and Cell Cycle of Small Micromeres in Embryos of the Sea Urchin, Hemicentrotus pulcherrimus , 1990, Development, growth & differentiation.

[22]  R. Kuraishi,et al.  Cell Movements during Gastrulation of Starfish Larvae. , 1992, The Biological bulletin.

[23]  M. T. Kozlowski,et al.  Developmental potential of muscle cell progenitors and the myogenic factor SUM-1 in the sea urchin embryo , 1993, Mechanisms of Development.

[24]  B. Brandhorst,et al.  Stimulation of tubulin gene transcription by deciliation of sea urchin embryos , 1987, Molecular and cellular biology.

[25]  R. Britten,et al.  Lineage and fate of each blastomere of the eight-cell sea urchin embryo. , 1987, Genes & development.

[26]  C. Ettensohn Cell interactions in the sea urchin embryo studied by fluorescence photoablation. , 1990, Science.

[27]  T. Gustafson,et al.  CELLULAR MOVEMENT AND CONTACT IN SEA URCHIN MORPHOGENESIS , 1967, Biological reviews of the Cambridge Philosophical Society.

[28]  S. Ruffins,et al.  A clonal analysis of secondary mesenchyme cell fates in the sea urchin embryo. , 1993, Developmental biology.

[29]  R. Raff,et al.  RAPID EVOLUTION OF GASTRULATION MECHANISMS IN A SEA URCHIN WITH LECITHOTROPHIC LARVAE , 1991, Evolution; international journal of organic evolution.

[30]  S. Ruffins,et al.  Cell Interactions in the Sea Urchin Embryo , 1996 .

[31]  Sven Hörstadius,et al.  Experimental embryology of echinoderms , 1973 .

[32]  G. Technau,et al.  The fate of the CNS midline progenitors in Drosophila as revealed by a new method for single cell labelling. , 1994, Development.

[33]  R. Britten,et al.  Whole mount in situ hybridization shows Endo 16 to be a marker for the vegetal plate territory in sea urchin embryos , 1993, Mechanisms of Development.

[34]  R A Robb,et al.  Interactive display and analysis of 3-D medical images. , 1989, IEEE transactions on medical imaging.

[35]  R. Burke,et al.  Cell movements during the initial phase of gastrulation in the sea urchin embryo. , 1991, Developmental biology.