STRUCTURAL VARIATIONS DURING MITOSIS IN THE CHICK EMBRYO

Structural Variations during Mitosis in the Chick Embryo

Selected tissues from chick embryos were fixed in 2% glutaraldehyde and 1% OsO(4), both buffered at pH 7.6 with Veronal-acetate, and were embedded in Maraglas or Araldite. Two types of cell division have been noted. Generally, epithelial cells divide predominantly by a shortening of the chromosome-to-pole distance rather than by spindle elongation; mesenchymal cells undergo extensive spindle el...

Teratogenic Effect of Adenosine on Chick Embryo in the Egg

This article has no abstract.

O6-alkylguanine-DNA alkyltransferase in the chick embryo during development.

In the whole embryo, O6-alkylguanine-DNA alkyltransferase (AT) activity increased until day 9 of development and declined sharply after day 13. AT activity of the liver was greatest between day 12 and day 20 and decreased fast after hatching. In the brain, AT activities reached a maximum at day 17 and 18 and declined sharply after hatching. At two developmental stages with different AT activiti...

Origin of phospholipids in the chick embryo during development.

Cleavage in the chick embryo.

Chick embryos ranging from the stage of first cleavage to that of about 700 cells were removed from the oviduct and examined by transmission electron microscopy. Beneath the cell membrane is yolk-free cortical region containing microfilaments. Beneath this lies cytoplasm which contains yolk spheres which are graded in size, the dorsal ones being smaller than the ventral ones. The subgerminal pe...