The structure of C-banded human metaphase chromosomes as observed by atomic force microscopy.
The ultrastructure of C-banded human metaphase chromosomes was studied by the combined use of light microscopy and atomic force microscopy (AFM). Light microscopy of the C-banded chromosomes showed that the centromeric regions of all chromosomes except the Y chromosome were positively stained. AFM further revealed that the C-positive region was higher than the C-negative region. The area of the C-positive region was specific depending on each chromosome; it ranged from the centromere to the proximal end of the long arm in chromosome 1, while it was restricted to the centromere in chromosomes 2 and 3. At higher magnification, chromatin fibers about 50 nm thick were clearly shown in the entire length of the chromosomes. In the C-positive region, these chromatin fibers were densely packed, while chromatin fibers were loosely packed with gentle twisting in the C-negative region. These AFM findings suggest that certain factors related to the chromatin fiber compaction remain in the C-positive region even after successive C-banging treatment.
Fukushi
Daisuke
D
Division of Microscopic Anatomy and Bio-imaging, Department of Cellular Function, Niigata University Graduate School of Medical and Dental Sciences, Niigata 981-8510, USA.
Ushiki
Tatsuo
T
D002503:Centromere / Q000648:ultrastructure; D002843:Chromatin / Q000648:ultrastructure; D002871:Chromosome Banding; D002877:Chromosomes, Human / Q000648:ultrastructure*; D006801:Humans; D008297:Male; D008677:Metaphase; D018625:Microscopy, Atomic Force
D002843:Chromatin