抄録
An electron microsocopical study by a modification of the surface-spreading whole-mount technique was performed on the morphology of mitotic chromosomes and elementary chromatin fibrils isolated from PHA-stimulated human lymphocytes, spermatocytes of the grasshopper, erythrocytes of the newt, and some other cells. A symmertical similarity in the spacing and the size of looping fibrils, which would suggest a gene-locus-specific segmental orderliness in the arrangement of the elementary chromatin fibrils of mitotic chromosomes, was identifiable in the individual homologous sister chromatid pairs of human colcemid chromosomes. An elementary chromatin fibril with a diameter of 200-300Å is conceived as a single DNA molecule which is gradually packed into a rope-like structure in a form of supercoils: a series of much-folded supertwists DNA double helices bundled by DNA-linked proteins. The mechanically stretched fibrils without any dissociation of their chemical components seemed to provide a support for this supposition.
