Abstract
Barley chromosomes were prepared for high-resolution scanning electron microscopy using a combination of enzyme maceration, treatment in acetic acid and osmium impregnation using thiocarbohydrazide. Using this technique, the three-dimensional ultra-structure of interphase nuclei and mitotic chromosomes was examined. In interphase, different levels of chromatin condensation were observed, consisting of fibrils 10 nm in diameter, 20- to 40-nm fibres and a higher order complex. In prophase, globular and strand-like structures composed of 20- to 40-nm fibres were dominant. As the cells progressed through the cell cycle and the chromatin condensed, globular and strand-like structures (chromomeres) were coiled and packed to form chromosomes. Chromomeres were observed as globular protuberances on the surface of metaphase chromosomes. These findings indicate that the chromomere is a fundamental substructure of the higher order architecture of the chromosome. In the centromeric region, there were no globular protuberances, but 20- to 40-nm fibres were folded compactly to form a higher level organization surrounding the chromosomal axis.
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Iwano, M., Fukui, K., Takaichi, S. et al. Globular and Fibrous Structure in Barley Chromosomes Revealed by High-Resolution Scanning Electron Microscopy. Chromosome Res 5, 341–349 (1997). https://doi.org/10.1023/B:CHRO.0000038766.53836.c3
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DOI: https://doi.org/10.1023/B:CHRO.0000038766.53836.c3