Immunolocalization of Fibronectin and Laminin in the Amphibian Intestine During Spontaneous and Triiodothyronine-Induced Metamorphosis: (laminin/fibronectin/extraepithelial matrix/intestine/amphibian).

Fibronectin and laminin were detected by indirect immunofluorescence in the intestine of Alytes obstetricans (anuran amphibian) during triiodothyronine (T3)-induced metamorphosis and spontaneous post-embryonic development. Fibronectin was first detected between a small number of connective tissue cells. As T3-treatment and spontaneous development progressed, fibronectin became detectable as a fine network extending throughout the whole thickness of the connective tissue and particularly in the core of the developing epithelial folds.

Lithium induces dorsal-type migration of mesodermal cells in the entire marginal zone of urodele amphibian embryos.

The effect of lithium (Li) on gastrulation movements was investigated during the development of the urodele amphibianPleurodeles waltl. Attention was focused on mesodermal cell migration. Under conditions of Li treatment providing a maximal enhancement of dorsoanterior structures, it was found that the dorsoventral polarity of gastrulation was abolished.

Implication of Cytoplasmic Factors in the Lethality of Bufonidae Nucleocytoplasmic Hybrids: (cytoplasmic factors/nucleocytoplasmic hybrids/bufonidae).

The nucleocytoplasmic hybrid combination performed by nuclear graft between B. bufo nucleus and B. calamita egg is 95% lethal during gastrulation mostly at the young gastrula stage (75%) and to a lesser extent at the yolk plug stage (20%).

Cytoplasmic Influence on Lethality in Nucleocytoplasmic and Natural Hybrids between Bufo Calamita Laur and Bufo Bufo L. (Amphibia, Anura).

Nucleocytoplasmic interactions have been studied through nuclear and cytoplasmic grafts. Bufo bufo nuclei transplanted in Bufo calamita eggs provoked 95% lethality during gastrulation. Influence of the cytoplasm in such a nucleocytoplasmic incompatibility has been studied through cytoplasmic fractionation and grafting of the fractions obtained.