- 著者
- Taiki Kobayashi Masako Takahashi Ryo Nishijima Ryuji Sugiyama Kotaro Ishii Shigeyuki Kawano Yusuke Kazama
- 出版者
- Japan Mendel Society, International Society of Cytology
- 雑誌
- CYTOLOGIA (ISSN:00114545)
- 巻号頁・発行日
- vol.86, no.4, pp.323-328, 2021-12-25 (Released:2021-12-24)
- 参考文献数
- 43
- 被引用文献数
- 2
Cytology requires chromosome specimens, thus, effective preparation methods are needed. Chromosome specimens are frequently prepared from plant root tips. Furthermore, cell cycle synchronization using chemical reagents is applied to obtain a large number of metaphase chromosome specimens. In this study, we focused on the timing of root tip sampling, which is optimal for the preparation of chromosome specimens of the dioecious plant Silene latifolia. The timing was determined from the time seeds were subjected to a germination treatment. Observation of metaphase chromosomes using microscopy revealed that the number of mitotic cells peaked 54 h after the germination treatment. This trend was also observed when the DNA synthesis inhibitor aphidicolin was administered from 24 to 9 h before sampling time points. We used ice-cold treatment for 8, 16, and 32 h as a chromosome condensation method. The 16 h treatment produced suitable chromosome specimens showing satellite ends of chromosomes, whereas the 32 h treatment produced well-condensed chromosome specimens, which were suitable for counting chromosome numbers. Our findings suggest that the timing of root tip sampling is essential for effectively producing plant chromosome specimens.
- 著者
- Yoichi Sato Tomonari Hirano Yoriko Hayashi Nobuhisa Fukunishi Tomoko Abe Shigeyuki Kawano
- 出版者
- Japan Mendel Society, International Society of Cytology
- 雑誌
- CYTOLOGIA (ISSN:00114545)
- 巻号頁・発行日
- vol.86, no.4, pp.291-295, 2021-12-25 (Released:2021-12-24)
- 参考文献数
- 29
- 被引用文献数
- 3
In Undaria pinnatifida, an effective method for mutant screening in sporophytes has not been established. The present study developed a novel mutant screening method for Undaria sporophyte by combining gametophyte mutagenesis with heavy-ion beam and land-based tank culture system. When we irradiated gametophytes and sporophytes with carbon- and argon-ion beams, survival rates of the female gametophytes and the sporophytes decreased with increasing dose. However, those of the male gametophyte did not decrease after both of the irradiations. Mutant screening during the sporophyte development was performed by using a land-based tank culture system. High-growth plants were selected in the first mutant (M1) population derived from the irradiated materials. We successfully obtained mutant candidates with higher growth than the wild type in the M2 generation obtained from brother-sister inbreeding of selected M1 plants. Four high-growth mutant candidate lines were selected from M2 populations of 48 lines. The mutant candidates were derived from 3 lines of the gametophyte irradiation and 1 line of the sporophyte irradiation, suggesting that the materials for the irradiation are applicable for mutant induction. The mutant screening method and the selected mutant candidates would advance the breeding and molecular biology in U. pinnatifida.
- 著者
- Maki Yamamoto Shinji Handa Masanobu Kawachi Shinichi Miyamura Tamotsu Nagumo Aiko Hirata Shigeyuki Kawano
- 出版者
- Japan Mendel Society, International Society of Cytology
- 雑誌
- CYTOLOGIA (ISSN:00114545)
- 巻号頁・発行日
- vol.81, no.1, pp.35-39, 2016-03-25 (Released:2016-04-11)
- 参考文献数
- 9
- 被引用文献数
- 4 6
Stichococcus Nägeli is a unicellular green algal species that belongs to the Trebouxiophyceae. Stichococcus bacillaris Nägeli NIES-3639 propagates by binary fission, but can form a filament without separating into two daughter cells. Transmission electron microscopy showed that cytokinesis starts according to invagination of the plasma membrane at the plane of division. Synthesis of the daughter cell wall occurs on the surface of invaginating plasma membrane during the protoplast division phase. The mother cell wall may cleave after protoplast division in either the single-cell or filament state. Field emission scanning electron microscopy revealed scars of cleaved mother cell walls from the single-cell state, two-cell state after cell division, and four-cell state during filament formation. Because the mother cell wall was cleaved, the delay of the daughter cell separation may have caused filament formation. Since this cell division cycle repeats rapidly, it may begin before the separation of the daughter cells yielded by the former cell cycle.
- 著者
- Shuhei Ota Kenshiro Oshima Tomokazu Yamazaki Tsuyoshi Takeshita Kateřina Bišová Vilém Zachleder Masahira Hattori Shigeyuki Kawano
- 出版者
- Japan Mendel Society, International Society of Cytology
- 雑誌
- CYTOLOGIA (ISSN:00114545)
- 巻号頁・発行日
- vol.84, no.4, pp.323-330, 2019-12-25 (Released:2019-12-20)
- 参考文献数
- 45
- 被引用文献数
- 5
The genus Chlorella is a well-known member of the green algal class Trebouxiophyceae, which is characterized by an immotile and asexual life cycle. Here, we performed an analysis of the whole genome and transcriptome of Parachlorella kessleri NIES-2152 with emphasis on the evolution of meiosis and the flagellar proteins. The Parachlorella transcriptomic data showed that the MID-related RWP-RK genes and meiosis-specific and flagellar proteins were expressed; at the transcriptional level, the DNA repair protein RAD50 was upregulated in the stationary phase, with four-fold more reads per kilobase of transcript per million mapped reads (RPKM) compared with the early stage of culture. In contrast, radial spoke protein genes were down-regulated in the stationary phase. These results suggest that genes for meiotic and flagellar proteins are culture stage-dependent and retain their functions. We presume that the algae lost some of the genes for meiosis and the flagella during asexual evolution, but other genes still possess biological functions other than those related to the flagellum and meiosis.
- 著者
- Shigeyuki Kawano
- 出版者
- 日本メンデル協会、国際細胞学会
- 雑誌
- CYTOLOGIA (ISSN:00114545)
- 巻号頁・発行日
- vol.82, no.2, pp.219-219, 2017-03-25 (Released:2017-05-11)
- 参考文献数
- 1
There is an injustice in this article by Talukdar, D. and Biswas, A. K. (2007). The editorial committee decided to retract it immediately.The injustice is apparent figure manipulation; Parts of Figs. 39 and 41 were inversed and imposed in Figs. 37 and 38, respectively.