Untersuchungen über die feineren Struktur des Chromosoms mit Hilfe des Elektronen-Übermikroskops

Researches on the Fine Structure of Chromosomes by Means of an Electron Microscope

“…The size of each chromomere has been estimated roughly as 1,000 A in diameter. As Yasuzumi (1947) and Pease and Baker (1949) have demonstrated, the larger granules are associated with heavy bands than are the smaller ones. The smallest chromomere was estimated as 180 A in diameter (G. Yasuzumi 1947).…”

“…As Yasuzumi (1947) and Pease and Baker (1949) have demonstrated, the larger granules are associated with heavy bands than are the smaller ones. The smallest chromomere was estimated as 180 A in diameter (G. Yasuzumi 1947). Each interband in transverse section appears cocoon-shaped or irregu larly oval in shape, having a vacant space in the center.…”

“…It seems th at these granules are really holes produc ed by the retreat of chromone mata, because, as has been shown by Y . Yoshida (1949) , the chromonemata become fragile and contract by the activity of supersonic vibration Th e matrix, on the contrary , as d emonstrated by G. Yasuzumi (1947) , h as much greater tenacity against the vibration and has greater density A more definite information may be obtained when the sectioned material is examined by means of silver impregnation (Fig. 3).…”

“…The methods employed for the electron microscopic study of these chromosomes by previous authors are: 1) the isolation of the chromosome by preservation in cold water for several days (G. Yasuzumi 1947), 2) the preparation and isolation of chromatin threads by differential centri fugation of disrupted nuclei (W. Hovanitz 1947), 3) the cutting of very thin microtome sections of the chromosome imbedded in porlodion and paraffin (D. C. Pease and R. F. Baker 1949), 4) the smear preparations with lanthanum acetate solution (J. Schultz, R. C. MacDuffee, and T. F. Anderson 1949), and 5) the replica method (S. L. Palay and A. Claude 1949). This preparation was investigated with Bielschowsky's method modified by S. Nanjo (1947), and also by the aid of the electron microscope.…”