The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)
MeSH Review


Welcome! If you are familiar with the subject of this article, you can contribute to this open access knowledge base by deleting incorrect information, restructuring or completely rewriting any text. Read more.

Disease relevance of Blastula

  • In addition, continuous exposure of embryos, beginning with the hatched blastula stage, to heat killed Vibrio diazatrophicus, a marine pathogen of sea urchins, significantly increased Sp064 message content in plutei compared to unexposed controls [1].

High impact information on Blastula

  • Xenopus blastula cells activate different mesodermal genes as a concentration-dependent response to activin, which behaves like a morphogen [2].
  • The sqt gene is expressed in a dorsal region of the blastula that includes the extraembryonic yolk syncytial layer (YSL) [3].
  • The organizer is formed in an equatorial sector of the blastula stage amphibian embryo by cells that have responded to two maternal agents: a general mesoendoderm inducer (involving the TFG-beta signaling pathway) and a dorsal modifier (probably involving the Wnt signaling pathway) [4].
  • Here we conclude from the in situ analysis of blastula tissue containing activin-loaded beads that cells respond directly to changing morphogen concentrations in a way that resembles a ratchet-like process [5].
  • One form of H2A and one form of H2B are synthesized only during the period from fertilization to the blastula stage [6].

Biological context of Blastula

  • Strong support for the operation of a morphogen gradient mechanism in vertebrate development has come from the biochemical experiments of Green and Smith, who induced different kinds of gene expression in amphibian blastula cells exposed to small changes in activin concentration [5].
  • Coincidently, early H1 genes, whose peak expression is also at the early blastula stage, all contain the same core consensus sequence (GGGCGG) [7].
  • When this GC-rich sequence (GGGCTG) is converted to a perfect core Sp1 sequence (GGGCGG), the H1-beta transcripts accumulate to much greater levels and their peak accumulation is shifted to the early blastula stage rather than late blastula and gastrula stages of development [7].
  • The fluorescence pattern indicates that fibronectin is found on the cell surfaces and between cells in the blastula and gastrula stages, indicating that it plays a role in cell adhesion [8].
  • A nearly full-length cDNA clone (HE6) encoding the entire sequence of the hatching enzyme was isolated from a prehatching blastula lambda gt11 cDNA library [9].

Anatomical context of Blastula

  • Injection of Xwnt-8 mRNA into 2-cell Xenopus embryos does not induce mesoderm formation in animal cap ectoderm isolated from these embryos at the blastula stage, but alters the response of this tissue to mesoderm induction by bFGF [10].
  • In the first experiment, donor cells, previously labeled by injecting fluorescein isothiocyanate-dextran into the zygote, were isolated from blastulae; approximately 1000 of these cells were microinjected into each unlabeled recipient embryo of the same developmental stage [11].
  • Maternal geminin mRNA is found throughout the animal hemisphere from oocyte through late blastula [12].
  • In a second series of experiments, we studied the expression of TN mRNA and protein in combinations between animal and vegetal stage-6 blastomeres and in stage-8 blastula animal caps treated with activin A or basic fibroblastic growth factor (b-FGF) [13].
  • Cyp26 is first expressed in the presumptive anterior neural ectoderm and the blastoderm margin at the late blastula [14].

Associations of Blastula with chemical compounds

  • This paper documents the evidence that the large oligomeric glycoprotein complexes of unknown function first isolated as 22S particles from sea urchin embryos are the sole agents responsible for the adhesive integrity of sea urchin blastula embryos [15].
  • Zygotes injected with constructs were cultured to the blastula stage in the presence of a heavy-metal chelator and then incubated in the presence or absence of cadmium [16].
  • Amphibian blastulae that are treated with lithium (Li) develop into embryos that consist almost exclusively of head structures [17].
  • Adenosine induces dormancy in starfish blastulae [18].
  • Integrin alpha 5 is expressed at relatively high levels during cleavage, blastula and gastrula stages suggesting that it may represent the major integrin expressed in the early embryo [19].

Gene context of Blastula

  • ApoE transcripts were also observed in the deep cell layer during blastula stage, in numerous ectodermal derivatives after gastrulation, and after 3 days of development in a limited number of cells both in brain and in the eyes [20].
  • Cyclin D and cdk4 are required for normal development beyond the blastula stage in sea urchin embryos [21].
  • Deletion of these control elements abolishes Boz-dependent repression of bmp2b in the early blastula [22].
  • These data indicate that Gata5 is involved both in the generation of endodermal cells at late blastula stages and in the maintenance of endodermal sox17 expression during gastrulation [23].
  • Neural induction in the absence of mesoderm: beta-catenin-dependent expression of secreted BMP antagonists at the blastula stage in Xenopus [24].

Analytical, diagnostic and therapeutic context of Blastula

  • By in situ hybridization with digoxygenin-labelled RNA probes, the BP10 transcripts were only detected in a limited area of the blastula, showing that the transcription of the BP10 gene is also spatially controlled [25].
  • In RT-PCR analysis, the expression of dorsal gene, chordin was activated in the explants isolated after time 4.0 (about the 4000-cell stage which corresponds to the mid blastula transition (MBT)) at control stage 10 [26].
  • Northern blot analysis revealed that abundant maternal FAK transcript is present in Xl eggs, with levels decreasing slightly through cleavage and early blastula stages [27].
  • Three major glycan fractions of 580 kDa (g580), 150 kDa (g150), and 2 kDa (g2) were isolated and purified from Lytechinus pictus sea urchin embryos at the mesenchyme blastula stage by gel filtration and high pressure liquid chromatography [28].
  • In this investigation the catecholamines dopamine, norepinephrine and epinephrine and their precursor, dopa and metabolites were determined in eight different embryonic stages of the sea urchin, Lytechinus pictus from hatched blastula to late pluteus larva, using high performance liquid chromatography with electrochemical detection [29].


  1. The gene encoding the sea urchin complement protein, SpC3, is expressed in embryos and can be upregulated by bacteria. Shah, M., Brown, K.M., Smith, L.C. Dev. Comp. Immunol. (2003) [Pubmed]
  2. The interpretation of position in a morphogen gradient as revealed by occupancy of activin receptors. Dyson, S., Gurdon, J.B. Cell (1998) [Pubmed]
  3. Zebrafish organizer development and germ-layer formation require nodal-related signals. Feldman, B., Gates, M.A., Egan, E.S., Dougan, S.T., Rennebeck, G., Sirotkin, H.I., Schier, A.F., Talbot, W.S. Nature (1998) [Pubmed]
  4. Formation and function of Spemann's organizer. Harland, R., Gerhart, J. Annu. Rev. Cell Dev. Biol. (1997) [Pubmed]
  5. Direct and continuous assessment by cells of their position in a morphogen gradient. Gurdon, J.B., Mitchell, A., Mahony, D. Nature (1995) [Pubmed]
  6. Stage-specific switches in histone synthesis during embryogenesis of the sea urchin. Cohen, L.H., Newrock, K.M., Zweidler, A. Science (1975) [Pubmed]
  7. Both basal and ontogenic promoter elements affect the timing and level of expression of a sea urchin H1 gene during early embryogenesis. Lai, Z.C., Maxson, R., Childs, G. Genes Dev. (1988) [Pubmed]
  8. Fibronectin in the developing sea urchin embryo. Spiegel, E., Burger, M., Spiegel, M. J. Cell Biol. (1980) [Pubmed]
  9. Early expression of a collagenase-like hatching enzyme gene in the sea urchin embryo. Lepage, T., Gache, C. EMBO J. (1990) [Pubmed]
  10. Xwnt-8 modifies the character of mesoderm induced by bFGF in isolated Xenopus ectoderm. Christian, J.L., Olson, D.J., Moon, R.T. EMBO J. (1992) [Pubmed]
  11. Rainbow trout chimeras produced by injection of blastomeres into recipient blastulae. Nilsson, E.E., Cloud, J.G. Proc. Natl. Acad. Sci. U.S.A. (1992) [Pubmed]
  12. Geminin, a neuralizing molecule that demarcates the future neural plate at the onset of gastrulation. Kroll, K.L., Salic, A.N., Evans, L.M., Kirschner, M.W. Development (1998) [Pubmed]
  13. Expression of tenascin mRNA in mesoderm during Xenopus laevis embryogenesis: the potential role of mesoderm patterning in tenascin regionalization. Umbhauer, M., Riou, J.F., Spring, J., Smith, J.C., Boucaut, J.C. Development (1992) [Pubmed]
  14. Distinct roles for Fgf, Wnt and retinoic acid in posteriorizing the neural ectoderm. Kudoh, T., Wilson, S.W., Dawid, I.B. Development (2002) [Pubmed]
  15. Functional characterization of toposomes from sea urchin blastula embryos by a morphogenetic cell aggregation assay. Matranga, V., Kuwasaki, B., Noll, H. EMBO J. (1986) [Pubmed]
  16. Structure of an ectodermally expressed sea urchin metallothionein gene and characterization of its metal-responsive region. Harlow, P., Watkins, E., Thornton, R.D., Nemer, M. Mol. Cell. Biol. (1989) [Pubmed]
  17. Lithium changes the ectodermal fate of individual frog blastomeres because it causes ectopic neural plate formation. Klein, S.L., Moody, S.A. Development (1989) [Pubmed]
  18. Adenosine induces dormancy in starfish blastulae. Tsuchimori, N., Miyashiro, S., Shibai, H., Ikegami, S. Development (1988) [Pubmed]
  19. Integrin alpha subunit mRNAs are differentially expressed in early Xenopus embryos. Whittaker, C.A., DeSimone, D.W. Development (1993) [Pubmed]
  20. Both apolipoprotein E and A-I genes are present in a nonmammalian vertebrate and are highly expressed during embryonic development. Babin, P.J., Thisse, C., Durliat, M., Andre, M., Akimenko, M.A., Thisse, B. Proc. Natl. Acad. Sci. U.S.A. (1997) [Pubmed]
  21. Cyclin D and cdk4 are required for normal development beyond the blastula stage in sea urchin embryos. Moore, J.C., Sumerel, J.L., Schnackenberg, B.J., Nichols, J.A., Wikramanayake, A., Wessel, G.M., Marzluff, W.F. Mol. Cell. Biol. (2002) [Pubmed]
  22. bozozok directly represses bmp2b transcription and mediates the earliest dorsoventral asymmetry of bmp2b expression in zebrafish. Leung, T., Bischof, J., Söll, I., Niessing, D., Zhang, D., Ma, J., Jäckle, H., Driever, W. Development (2003) [Pubmed]
  23. Multiple roles for Gata5 in zebrafish endoderm formation. Reiter, J.F., Kikuchi, Y., Stainier, D.Y. Development (2001) [Pubmed]
  24. Neural induction in the absence of mesoderm: beta-catenin-dependent expression of secreted BMP antagonists at the blastula stage in Xenopus. Wessely, O., Agius, E., Oelgeschläger, M., Pera, E.M., De Robertis, E.M. Dev. Biol. (2001) [Pubmed]
  25. Spatial and temporal expression pattern during sea urchin embryogenesis of a gene coding for a protease homologous to the human protein BMP-1 and to the product of the Drosophila dorsal-ventral patterning gene tolloid. Lepage, T., Ghiglione, C., Gache, C. Development (1992) [Pubmed]
  26. Dorsal induction from dorsal vegetal cells in Xenopus occurs after mid-blastula transition. Nagano, T., Ito, Y., Tashiro, K., Kobayakawa, Y., Sakai, M. Mech. Dev. (2000) [Pubmed]
  27. Cloning of a Xenopus laevis cDNA encoding focal adhesion kinase (FAK) and expression during early development. Zhang, X., Wright, C.V., Hanks, S.K. Gene (1995) [Pubmed]
  28. Isolation and characterization of a new class of acidic glycans implicated in sea urchin embryonal cell adhesion. Papakonstantinou, E., Misevic, G.N. J. Cell. Biochem. (1993) [Pubmed]
  29. Developmental regulation of catecholamine levels during sea urchin embryo morphogenesis. Anitole-Misleh, K.G., Brown, K.M. Comp. Biochem. Physiol., Part A Mol. Integr. Physiol. (2004) [Pubmed]
WikiGenes - Universities