Abstract
Previous methods which employed simple sucrose or salt solutions to isolate yolk platelets have failed to preserve their superficial layer, and the preparations obtained generally exhibit some contamination when observed with the light or electron microscope. When yolk platelets are suspended in a sucrose-polyvinylpyrrolidinone medium, however, they remain relatively intact and their superficial layer is not lost to the medium. A method, which takes advantage of this fact, is described for the isolation of frog (Rana pipiens) yolk platelets which are free from nuclear contamination and practically free from cytoplasmic contamination. After such platelets are treated with distilled water, the superficial layer is no longer seen and a new dense and granular matrix is frequently found surrounding the crystalline main body. The significance of this and other observations concerning the effects of calcium and ethylenediamine tetraacetate are discussed.
Full Text
The Full Text of this article is available as a PDF (1.2 MB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- GILBERT L. I., GROSS P. R. Chemistry and ultrastructure of amphibian yolk platelets. Trans N Y Acad Sci. 1956 Dec;19(2):108–117. doi: 10.1111/j.2164-0947.1956.tb00514.x. [DOI] [PubMed] [Google Scholar]
- KARASAKI S., KOMODA T. Electron micrographs of a crystalline lattice structure in yolk platelets of the amphibian embryo. Nature. 1958 Feb 8;181(4606):407–408. doi: 10.1038/181407a0. [DOI] [PubMed] [Google Scholar]
- KARASAKI S. Studies on amphibian yolk 1. The ultrastructure of the yolk platelet. J Cell Biol. 1963 Jul;18:135–151. doi: 10.1083/jcb.18.1.135. [DOI] [PMC free article] [PubMed] [Google Scholar]
- PANIJEL J. L'organisation du vitellus dans les oeufs d'amphibiens. Biochim Biophys Acta. 1950 Jun;5(3/4):343–357. doi: 10.1016/0006-3002(50)90181-8. [DOI] [PubMed] [Google Scholar]
- PIERCE C. H., DUBOS R. J., SCHAEFER W. B. Multiplication and survival of tubercle bacilli in the organs of mice. J Exp Med. 1953 Feb 1;97(2):189–206. doi: 10.1084/jem.97.2.189. [DOI] [PMC free article] [PubMed] [Google Scholar]
- ROUNDS D. E., FLICKINGER R. A. Distribution of ribonucleoprotein during neural induction in the frog embryo. J Exp Zool. 1958 Apr;137(3):479–499. doi: 10.1002/jez.1401370307. [DOI] [PubMed] [Google Scholar]
- SCHJEIDE O. A., URIST M. R. Proteins and calcium in egg yolk. Exp Cell Res. 1959 Apr;17(1):84–94. doi: 10.1016/0014-4827(59)90154-5. [DOI] [PubMed] [Google Scholar]
- WISCHNITZER S. The ultrastructure of yolk platelets of amphibian oocytes. J Biophys Biochem Cytol. 1957 Nov 25;3(6):1040–1042. doi: 10.1083/jcb.3.6.1040. [DOI] [PMC free article] [PubMed] [Google Scholar]