Mesoderm induction was first demonstrated by Pieter Nieuwkoop in 1969. By recombining animal and vegetal explants, which would in isolation originate ectoderm and endoderm, respectively, mesoderm formed from the animal cap cells (Nieuwkoop, 1969). Successive research has identified candidate mesoderm inducers within the TGFβ and FGF families of molecules (reviewed in Harland and Gerhart, 1997)....

Previous studies of the regulatory region of the SpHE (hatching enzyme) gene of the sea urchin Strongylocentrotus purpuratus (Wei, Z., Angerer, L.M., Gagnon, M.L. and Angerer, R.C. (1995) Characterization of the SpHE promoter that are spatially regulated along the animal-vegetal axis of the sea urchin embryo. Dev. Biol. 171, 195-211) have shown that approximately 330 bp is necessary and suffici...

Dishevelled (Dsh) is a key signaling molecule in the canonical Wnt pathway. Although the mechanism by which Dsh transduces a Wnt signal remains elusive, the subcellular localization of Dsh may be critical for its function. In the early sea urchin embryo, Dsh is concentrated in punctate structures within the cytoplasm of vegetal blastomeres. In these cells, Dsh stabilizes beta-catenin and causes...

The resumption of the meiotic cycle (maturation) induced by 1-methyladenine in prophase-arrested starfish oocytes is indicated by the breakdown of the germinal vesicle and is characterized by the increased sensitivity of the Ca2+ stores to inositol 1,4,5-trisphosphate (InsP3) to InsP3 starting at the animal hemisphere (where the germinal vesicle was originally located) and propagating along the...

The use of dynamized substances in agriculture, especially on plants, has been growing fast. Diseases or physiological disorders are not considered merely the results action physiopathological agents and abiotic factors, but a consequence loss homeostasis organism. Notions proper to homeopathy used several areas agriculture. Although effective have observed both academic field milieus, too much...