Biomaterial Database

Synthesis of a metallothionein-like protein by developing turkey embryos maintained in long-term, shell-less culture. 1984

M P Richards

Turkey embryos were maintained in long-term, shell-less culture to the age of 17 days. At this time, 10 cultures were given saline (controls), and 10 cultures were given 30 micrograms zinc in saline (+Zn). In addition, all cultures received 5 microCi each of [35S]cystine and 65Zn dissolved in the saline and applied to the chorioallantoic membrane. After a further 20 h of incubation, no significant differences were found for embryo, liver, or yolk sac weights nor for relative liver size, hematocrit, serum protein, or serum concentrations of zinc and copper for the control and + Zn cultures. The addition of zinc to the cultures significantly (p less than 0.01) elevated hepatic and yolk sac cytosol 65Zn and zinc concentrations. More than 70% of the increased 65Zn and zinc in the cytosol of liver and yolk sac could be accounted for as that bound to a low-molecular-weight metallothionein (MT)-like protein. Added zinc significantly (p less than 0.01) increased the incorporation of [35S]cystine and 65Zn into the MT-like protein from liver and yolk sac indicating de novo synthesis of this protein. Liver and yolk sac MT-like proteins eluted from DEAE Sephadex A-25 columns as a single predominant species. The synthesis of an MT-like protein by liver and yolk sac suggests a role in embryonic zinc homeostasis. Moreover, shell-less culture of the avian embryo appears to be a useful method for studying zinc metabolism during periods of embryonic growth and development.

UI	MeSH Term	Description	Entries
D008099	Liver	A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.	Livers
D008668	Metallothionein	A low-molecular-weight (approx. 10 kD) protein occurring in the cytoplasm of kidney cortex and liver. It is rich in cysteinyl residues and contains no aromatic amino acids. Metallothionein shows high affinity for bivalent heavy metals.	Isometallothionein,Metallothionein A,Metallothionein B,Metallothionein I,Metallothionein II,Metallothionein IIA
D003600	Cytosol	Intracellular fluid from the cytoplasm after removal of ORGANELLES and other insoluble cytoplasmic components.	Cytosols
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
D014422	Turkeys	Large woodland game BIRDS in the subfamily Meleagridinae, family Phasianidae, order GALLIFORMES. Formerly they were considered a distinct family, Melegrididae.	Meleagridinae,Meleagrididae
D015017	Yolk Sac	The first of four extra-embryonic membranes to form during EMBRYOGENESIS. In REPTILES and BIRDS, it arises from endoderm and mesoderm to incorporate the EGG YOLK into the DIGESTIVE TRACT for nourishing the embryo. In placental MAMMALS, its nutritional function is vestigial; however, it is the source of INTESTINAL MUCOSA; BLOOD CELLS; and GERM CELLS. It is sometimes called the vitelline sac, which should not be confused with the VITELLINE MEMBRANE of the egg.	Vitelline Sac of Embryo,Embryo Vitelline Sac,Embryo Vitelline Sacs,Sac, Yolk,Sacs, Yolk,Yolk Sacs
D015032	Zinc	A metallic element of atomic number 30 and atomic weight 65.38. It is a necessary trace element in the diet, forming an essential part of many enzymes, and playing an important role in protein synthesis and in cell division. Zinc deficiency is associated with ANEMIA, short stature, HYPOGONADISM, impaired WOUND HEALING, and geophagia. It is known by the symbol Zn.
D046508	Culture Techniques	Methods of maintaining or growing biological materials in controlled laboratory conditions. These include the cultures of CELLS; TISSUES; organs; or embryo in vitro. Both animal and plant tissues may be cultured by a variety of methods. Cultures may derive from normal or abnormal tissues, and consist of a single cell type or mixed cell types.	Culture Technique,Technique, Culture,Techniques, Culture