Cellular and Molecular Mechanisms in Biological System (CEMBIOS) Research Group, Department of Biology, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok Campus, West Java, 16424, Indonesia.
Institute of Crop Science, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, 305-8602, Japan.
Chromosome Res. 2021 Mar;29(1):51-62. doi: 10.1007/s10577-021-09650-9. Epub 2021 Feb 15.
Visualization of the chromosome ultrastructure has revealed new insights into its structural and functional properties. The use of new methods for revealing not only the surface but also the inner structure of the chromosome has been emerged. Some methods have long been used, such as conventional transmission electron microscopy (TEM). Although it has indispensably contributed to the revelation of the ultrastructure of the various biological samples, including chromosomes, some challenges have also been encountered, such as laborious sample preparation, limited view areas, and loss of information on some parts due to ultramicrotome sectioning. Therefore, a more advanced method is needed. Scanning electron microscopy (SEM) is also advantageous in the surface visualization of chromosome samples. However, it is limited by accessibility to gain the inner structure information. Focused ion beam/scanning electron microscopy (FIB/SEM) provides a way to investigate the inner structure of the samples in a direct slice-and-view manner to observe the ultrastructure of the inner part of the sample continuously and further construct a three-dimensional image. This method has long been used in the material science field, and recently, it has also been applied to biological research, such as in showing the inner structure of chromosomes. This review article presents the contributions of this new method to chromosome research and its recent developments in the inner structure of chromosome and discusses its current and potential applications to the high-resolution imaging of chromosomes.
染色体超微结构的可视化揭示了其结构和功能特性的新见解。已经出现了一些新的方法，不仅可以揭示染色体的表面结构，还可以揭示其内部结构。一些方法已经使用了很长时间，例如传统的透射电子显微镜（TEM）。虽然它对包括染色体在内的各种生物样本的超微结构的揭示做出了不可或缺的贡献，但也遇到了一些挑战，例如费力的样品制备、有限的观察区域以及由于超薄切片导致某些部分信息的丢失。因此，需要更先进的方法。扫描电子显微镜（SEM）在染色体样品的表面可视化方面也具有优势。然而，它受到可及性的限制，无法获取内部结构信息。聚焦离子束/扫描电子显微镜（FIB/SEM）提供了一种以直接切片和观察的方式研究样品内部结构的方法，可连续观察样品内部的超微结构，并进一步构建三维图像。这种方法在材料科学领域已经使用了很长时间，最近也已经应用于生物学研究，例如显示染色体的内部结构。本文综述了该新方法对染色体研究的贡献及其在染色体内部结构方面的最新进展，并讨论了其在染色体的高分辨率成像方面的当前和潜在应用。
