... functions prior to MBT. Thus, nuclear translocation of β-catenin has been reported prior to MBT as early as the 16-cell stage( Larabell et al., 1997 ; Miller et al., 1999 ). Furthermore, lithium, an inhibitor of GSK-3β( Klein and Melton, 1996 ; Stambolic et al., 1996 ), that enhances nuclear accumulation...

... in zebrafish embryos either by overexpression of dominant negative dn gsk3β mRNA or by lithium treatment after the midblastula transition phenocopies mbl . The loss of anterior neural tissue in mbl and lithium-treated embryos is preceded by posteriorization of presumptive anterior neuroectoderm during...

... downstream of β-catenin, in order to achieve tissue-specific effects. ‡Author for correspondence (e-mail: [email protected] ) 13 3 2001 © 2001. 2001 Xenopus Wnt Xwnt-8 Lithium GSK3β β-catenin Tcf Mesoderm Signalling Embryonic organisation requires cell-to-cell...

...Andrea Becchetti; Michael Whitaker ABSTRACT Lithium is a classical inhibitor of the phosphoinositide pathway and is teratogenic. We report the effects of lithium on the first cell cycles of sea urchin ( Lytechinus pictus ) embryos. Embryos cultured in 400 mM lithium chloride sea water showed marked...

... previously showed that aboral ectoderm-specific genes can be induced by 25 mM lithium chloride, which also induced endoderm formation (Wikramanayake, A. H., Brandhorst, B. P. and Klein, W. H. (1995). Development 121, 1497-1505). To ascertain if endoderm formation is a prerequisite for induction of aboral...

... primary patterning in the sea urchin embryo is not limited to a small vegetal center but extends along the entire AV axis. * Author for correspondence (e-mail: [email protected] ) 19 07 1996 © 1996 by Company of Biologists 1996 AV axis lithium embryoids micromeres sea...

... animal blastomeres with the embryo dorsalizing agent LiCl. Treatment with lithium alone did not induce normal trunk mesoderm in either blastomere. Lithium did, however, alter the competence of animal blastomeres to activin. Dorsal mesoderm was formed in the ventral blastomeres, as well as in the dorsal...

... the dorsalizing activity of the lithium ion and a panel of cytokines. The marginal zone has been fate mapped during gastrulation by colloidal gold labelling and it is shown that the ventral tissue undergoes substantial circumferential expansion. The fate map information is used to provide tissues of constant...

... of ciliated cells. As development proceeds the hatching gland pattern is altered, demonstrating the active changes involved in forming the face. Lithium, UV irradiation and retinoic acid can be used to alter the hatching gland pattern in specific ways which help to understand the underlying mechanisms...

... were generated by exposure to u.v. irradiation at the vegetal pole before 0·6 in the cell cycle, which generates embryos with dorsal axial deficiencies. Alternatively embryos were treated with 100 m m -lithium chloride between the 2-cell and 32-cell stage, which generates embryos with ventral axial...

... anteroposterior pattern dorsoventral pattern lithium D 2 O organizer The unfertilized Xenopus egg displays polarized cylindrical symmetry around an axis connecting the poles of the animal and vegetal hemispheres (these hemispheres henceforth abbreviated as AH and VH). The two hemispheres differ...

...Chester M. Regen; Richard A. Steinhardt The discovery that lithium treatment at blastula stages can induce axis formation suggested that it might act by respecifying the cytoplasmic rearrangement-generated dorsoventral pattern, so that ventral cells behave like their dorsal counterparts. We have...

...Lorna J. Breckenridge; R. L. Warren; Anne E. Warner ABSTRACT Xenopus embryos treated with 100 mM-lithium from the 2-to 4-cell stage to the early blastula stage (4h) failed to neurulate and developed without a discernible anteroposterior axis. The internal structure of defective embryos was grossly...