Papers by Rinyaporn Phengchat
Chromosome Research
Our understanding of the inner structure of metaphase chromosomes remains inconclusive despite in... more 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.
Scientific Reports
The attachment of spindle fibres to the kinetochore is an important process that ensures successf... more The attachment of spindle fibres to the kinetochore is an important process that ensures successful completion of the cell division. The Ca 2+ concentration increases during the mitotic phase and contributes microtubule stability. However, its role in the spindle organisation in mitotic cells remains controversial. Here, we investigated the role of Ca 2+ on kinetochore fibres in living cells. We found that depletion of Ca 2+ during mitosis reduced kinetochore fibre stability. Reduction of kinetochore fibre stability was not due to direct inhibition of microtubule polymerisation by Ca 2+ -depletion but due to elimination of one dynamic component of kinetochore, CENP-F from the kinetochore. This compromised the attachment of kinetochore fibres to the kinetochore which possibly causes mitotic defects induced by the depletion of Ca 2+ .
Scientific Reports
Chromosome condensation is essential for the faithful transmission of genetic information to daug... more Chromosome condensation is essential for the faithful transmission of genetic information to daughter cells during cell division. The depletion of chromosome scaffold proteins does not prevent chromosome condensation despite structural defects. This suggests that other factors contribute to condensation. Here we investigated the contribution of divalent cations, particularly Ca 2+ , to chromosome condensation in vitro and in vivo. Ca 2+ depletion caused defects in proper mitotic progression, particularly in chromosome condensation after the breakdown of the nuclear envelope. Fluorescence lifetime imaging microscopy-Förster resonance energy transfer and electron microscopy demonstrated that chromosome condensation is influenced by Ca 2+ . Chromosomes had compact globular structures when exposed to Ca 2+ and expanded fibrous structures without Ca 2+ . Therefore, we have clearly demonstrated a role for Ca 2+ in the compaction of chromatin fibres.
Scientific Reports
Chromosome condensation is essential for the faithful transmission of genetic information to daug... more Chromosome condensation is essential for the faithful transmission of genetic information to daughter cells during cell division. The depletion of chromosome scaffold proteins does not prevent chromosome condensation despite structural defects. This suggests that other factors contribute to condensation. Here we investigated the contribution of divalent cations, particularly Ca 2+ , to chromosome condensation in vitro and in vivo. Ca 2+ depletion caused defects in proper mitotic progression, particularly in chromosome condensation after the breakdown of the nuclear envelope. Fluorescence lifetime imaging microscopy-Förster resonance energy transfer and electron microscopy demonstrated that chromosome condensation is influenced by Ca 2+ . Chromosomes had compact globular structures when exposed to Ca 2+ and expanded fibrous structures without Ca 2+ . Therefore, we have clearly demonstrated a role for Ca 2+ in the compaction of chromatin fibres.
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Papers by Rinyaporn Phengchat