Structural concepts of chromosome axis. Chromosome scaffold and core within coiled mitotic chromatids

摘要

The presence of axial elements in human mitotic chromosomes has been demonstrated by means of specific pretreatments and silver staining for chromosomes fixed on glass slides. Isolation buffers of high or low ionic strength, used earlier for histone depletion and extraction, were used for demonstration of the coiled organization of metaphase chromatids. Subsequent staining by silver revealed scaffolding structures in chromonemal coils, and, deeply stained cores in compact metaphase chromatids. The reality of axial elements is discussed in terms of the element's presence and function in differentially contracted mitotic chromonemata and chromatids.