Nanotechnology Research Centre, National Research of Council, 11421 Saskatchewan Drive, T6G 2M9 Edmonton, Alberta, Canada.
Graduate School of Human Development and Environment, Kobe University, Tsurukabuto 3-11, Nada-ku, 657-8501 Kobe, Japan.
Micron. 2022 Sep;160:103328. doi: 10.1016/j.micron.2022.103328. Epub 2022 Jul 14.
The higher order structure of the metaphase chromosome has been an enigma for over a century and several different models have been presented based on results obtained by a variety of techniques. Some disagreements in the results between methods have possibly arisen from artifacts caused during sample preparation such as staining and dehydration. Therefore, we treated barley chromosomes with ionic liquid to minimize the effects of dehydration. We also observed chromosomes on a film with holes to keep pristine chromosome structure from being flattened as seen when placed on a continuous support film. A chromosome placed over a hole in a thin carbon film was mounted on a tomography holder, and its structure was observed in three dimensions (3D) using electron tomography. We found that there are periodic structures with 300-400 nm pitch along the axis in barley chromosomes. The pitch sizes are larger than those observed in human chromosomes.
中期染色体的高级结构已经困扰了一个多世纪，基于各种技术获得的结果，已经提出了几种不同的模型。不同方法之间的结果存在一些分歧，这可能是由于样品制备过程中染色和脱水等因素造成的人为假象。因此，我们用离子液体处理大麦染色体，以尽量减少脱水的影响。我们还在有孔的薄膜上观察染色体，以防止在连续支撑膜上观察到的染色体结构被压平。将一个穿过薄碳膜的孔的染色体安装在断层摄影支架上，并用电子断层摄影术在三维（3D）中观察其结构。我们发现，大麦染色体沿轴存在具有 300-400nm 间距的周期性结构。这些间距大小大于在人类染色体中观察到的大小。
