Fibronectin peptide DRVPHSRNSIT and fibronectin receptor peptide DLYYLMDL arrest gastrulation ofRana pipiens

Gastrulation is characterized by dramatic cell migration which is thought to require the interaction of cell adhesion molecules with extracellular molecules. We have tested two novel peptides, a fibronectin peptide and a fibronectin receptor peptide, for their effects on gastrulation of the leopard frogRana pipiens. The fibronectin peptide DRVPHSRNSIT corresponds to residues 1373–1383 of the cell-binding domain of fibronectin; the receptor peptide DLYYLMDL corresponds to residues 124–131 of 1 subunit of a variety of integrins including 51. Either of these peptides significantly inhibited gastrulation after being microinjected into mid-blastulae. These results indicate that these sequences may correspond to the ligand/receptor interaction sites of fibronectin and its receptor(s).     

Acetylcholine receptors in the gastrulating chick embryo

Summary Muscarinic acetylcholine receptors are present in the gastrulating chick embryo.     

Discovery of phosphatized gastrula fossils from the Doushantuo Formation, Weng’an, Guizhou Province, China

Globular fossils from Doushantuo phosphorites at the Weng’an area are for the first time identified as a gastrulation stage of phosphatized embryos. They are got from the fossiliferous remains after acetic acid maceration. The fossils are found together with formerly reported animal resting eggs and embryos of the earlier cleavage stage. The oblate-shaped fossils with the same size as those reported embryos and invaginate at the middle part into the embryos, show the characteristics of the late blastula to the early gastrula stage of the embryo development. This discovery convinces the existence of animal embryos at Doushantuo age and offers new facts for the studying of the affinity of related fossils, which are still controversial at present.