Abstract
Our understanding of the inner structure of metaphase chromosomes remains inconclusive despite intensive studies using multiple imaging techniques. Transmission electron microscopy has been extensively used to visualize chromosome ultrastructure. This review summarizes recent results obtained using two transmission electron microscopy-based techniques: electron tomography and electron diffraction. Electron tomography allows advanced three-dimensional imaging of chromosomes, while electron diffraction detects the presence of periodic structures within chromosomes. The combination of these two techniques provides results contributing to the understanding of local structural organization of chromatin fibers within chromosomes.
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Notes
The term chromosome spreading refers to deposition of swollen cell suspension onto a substrate. The cells break on impact with the substrate. Bundles of chromosomes from the cell then disperse on the substrate allowing observation of individual chromosomes.
Abbreviations
- AFM:
-
Atomic force microscopy
- BMI-BF4 :
-
1-butyl-3-methylimidazolium tetrafluoroborate
- EMI-BF4 :
-
1-ethy-3-methylimidazolium tetrafluoroborate
- DAB:
-
Diaminobenzidine
- CPD:
-
Critical point drying
- ED:
-
Electron diffraction
- ET:
-
Electron tomography
- FIB:
-
Focused ion beam
- GA:
-
Lutaraldehyde
- HEPES:
-
4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid
- IL:
-
Ionic liquid
- PBS:
-
Phosphate buffered saline
- PIPES:
-
Piperazine-N, N’bis(2-ethanesulfonic acid)
- Pt-blue:
-
Platinum blue
- SAXS:
-
Small angle X-ray scattering
- SBF:
-
Serial block face
- SEM:
-
Scanning electron microscope
- TA:
-
Tannic acid
- TEM:
-
Transmission electron microscope
- XRT:
-
X-ray tomography
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Acknowledgements
We would like to express our gratitude to Prof. Kiichi Fukui, Dr. Toshiyuki Wako, and Dr. Beth Sullivan for giving us the opportunity to write this review article. We are grateful to Prof. Kiichi Fukui and Prof. Nobuko Ohmido for their guidance, thoughtful insights, and motivation throughout the work on optimization of electron microscopy methods for chromosome imaging.
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Phengchat, R., Malac, M. & Hayashida, M. Chromosome inner structure investigation by electron tomography and electron diffraction in a transmission electron microscope. Chromosome Res 29, 63–80 (2021). https://doi.org/10.1007/s10577-021-09661-6
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DOI: https://doi.org/10.1007/s10577-021-09661-6