Biomaterial Database

A freeze-fracture and concanavalin A-binding study of the membrane of cleaving Xenopus embryos. 1976

E J Sanders, and R A Dicaprio

The freeze-fracture appearance and concanavalin A-binding capacity of the plasma membrane of cells of the cleaving Xenopus embryo have been examined up to the 16-cell stage. It was found that membrane on the outer surface of the embryo, which faces the vitelline membrane and is remote from cleavage furrows, and membrane in the shallow regions of the furrow possessed a high population of intramembranous particles on the PF-face (1171 per mum2). The EF-face of these membranes showed a lower particle population (245 per mum2). By contrast, membrane deep in the furrow and bounding the blastocoel did not display a face with high particle numbers. Both faces of this membrane, which is newly exposed as the furrow grows, were relatively poorly supplied with particles (93 per mum2). Therefore it appears that, in this tissue, newly added membrane possesses fewer intramembranous particles than the pre-existing membrane. Concanavalin A, as detected cytochemically using peroxidase and haemocyanin techniques, bound extensively to both particle-rich and particle-poor membrane. Thus there was no correlation between intramembranous particle frequency and degree of concanavalin A binding.

UI	MeSH Term	Description	Entries
D011952	Receptors, Concanavalin A	Glycoprotein moieties on the surfaces of cell membranes that bind concanavalin A selectively; the number and location of the sites depends on the type and condition of the cell.	Concanavalin A Binding Sites,Concanavalin A Receptors,Concanavalin A Receptor,Receptor, Concanavalin A
D011955	Receptors, Drug	Proteins that bind specific drugs with high affinity and trigger intracellular changes influencing the behavior of cells. Drug receptors are generally thought to be receptors for some endogenous substance not otherwise specified.	Drug Receptors,Drug Receptor,Receptor, Drug
D002462	Cell Membrane	The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.	Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
D005260	Female		Females
D005614	Freeze Fracturing	Preparation for electron microscopy of minute replicas of exposed surfaces of the cell which have been ruptured in the frozen state. The specimen is frozen, then cleaved under high vacuum at the same temperature. The exposed surface is shadowed with carbon and platinum and coated with carbon to obtain a carbon replica.	Fracturing, Freeze,Fracturings, Freeze,Freeze Fracturings
D006433	Hemocyanins	Metalloproteins that function as oxygen transport proteins in the HEMOLYMPH of MOLLUSKS and ARTHROPODS. They are characterized by two copper atoms, coordinated with HISTIDINE residues, that reversibly bind a single oxygen molecule; they do not contain HEME groups.	Hemocyanin,alpha-Haemocyanin,alpha-Hemocyanin,alpha-Hemocyanins,alpha Haemocyanin,alpha Hemocyanin,alpha Hemocyanins
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D014981	Xenopus	An aquatic genus of the family, Pipidae, occurring in Africa and distinguished by having black horny claws on three inner hind toes.
D015053	Zygote	The fertilized OVUM resulting from the fusion of a male and a female gamete.	Fertilized Ovum,Ovum, Fertilized,Fertilized Egg,Egg, Fertilized,Eggs, Fertilized,Fertilized Eggs,Zygotes