The 11th IROAST Seminar, organized by IROAST's assistant professor Takashi Ishida, was held on August 7.

Assistant Professor Shinichiro Komaki, Nara Institute of Science and Technology, gave a talk titled "The spindle assembly checkpoint in plants." About 60 students and faculty members attended the seminar and listened to his presentation attentively.

August 7, 2017: 11th IROAST Seminar－The spindle assembly checkpoint in plants

IROAST will hold the 11th IROAST Seminar－The spindle assembly checkpoint in plants－at Kurokami South Faculty of Science Bldg.1&2 C122 on August 7, 2017.

Assistant Professor Shinichiro KOMAKI, Nara Institute of Science and Technology will give a talk on his research about the spindle assembly checkpoint in plants. Everyone is welcome. We hope to see you at the seminar.

Please see the details of the seminar as follows.

The spindle assembly checkpoint (SAC) plays a key role for the fidelity of chromosome distribution by preventing anaphase onset until all chromosomes are correctly attached to the spindle. The core proteins of the SAC are highly conserved from yeast to plants, including MAD1, MAD2, MAD3/BUBR1, BUB1, BUB3 and MPS1. Lack of the SAC activity causes missegregation of chromosomes, resulting in aneuploidy and subsequently cell death in yeast and mammalian cells. Since changes in chromosome numbers and polyploidy are very common in plants, especially angiosperms, we wondered whether plants have an effective SAC. Here, we provide a functional framework of the core SAC proteins in Arabidopsis. We reveal that the model plant Arabidopsis thaliana, an ancient polyploid species, will delay mitosis in a SAC-dependent manner if the spindle is perturbed. However, our work also shows that the molecular architecture of the SAC is unique in plants. Moreover, the SAC is short-lived and cannot stay active for more than two hours after which the cell cycle is reset. This resetting opens the possibility for genome duplications and raises the hypothesis that a rapid termination of a SAC-induced mitotic arrest provides an adaptive advantage for plants impacting plant genome evolution.

Contact for the 11th IROAST Seminar contents: Assistant Professor Takashi ISHIDA
Email: ishida@sci.* (Please change “*” to “kumamoto-u.ac.jp”.)

Contact for IROAST seminar:
Email: szk-kiko@jimu.* (Please change “*” to “kumamoto-u.ac.jp”.)