- 著者
- Ryo Matsuzaki Yusuke Takashima Iwane Suzuki Masanobu Kawachi Hisayoshi Nozaki Seiichi Nohara Yousuke Degawa
- 出版者
- Japanese Society of Microbial Ecology / Japanese Society of Soil Microbiology / Taiwan Society of Microbial Ecology / Japanese Society of Plant Microbe Interactions / Japanese Society for Extremophiles
- 雑誌
- Microbes and Environments (ISSN:13426311)
- 巻号頁・発行日
- vol.36, no.2, pp.ME21011, 2021 (Released:2021-06-16)
- 参考文献数
- 31
- 被引用文献数
- 1
Chionaster nivalis is frequently detected in thawing snowpacks and glaciers. However, the taxonomic position of this species above the genus level remains unclear. We herein conducted molecular analyses of C. nivalis using the ribosomal RNA operon sequences obtained from more than 200 cells of this species isolated from a field-collected material. Our molecular phylogenetic analyses revealed that C. nivalis is a sister to Bartheletia paradoxa, which is an orphan basal lineage of Agaricomycotina. We also showed that C. nivalis sequences were contained in several previously examined meta-amplicon sequence datasets from snowpacks and glaciers in the Northern Hemisphere and Antarctica.
- 著者
- Lin Wei JONG Takayuki FUJIWARA Hisayoshi NOZAKI Shin-ya MIYAGISHIMA
- 出版者
- The Japan Academy
- 雑誌
- Proceedings of the Japan Academy, Series B (ISSN:03862208)
- 巻号頁・発行日
- vol.93, no.10, pp.832-840, 2017-12-11 (Released:2017-12-11)
- 参考文献数
- 31
- 被引用文献数
- 7
Volvocine algae constitute a green algal lineage comprising unicellular Chlamydomonas, four-celled Tetrabaena, eight to 32-celled Gonium, and others up to Volvox spp., which consist of up to 50,000 cells. These algae proliferate by multiple fissions with cellular growth up to several fold in size and subsequent successive cell divisions. Chlamydomonas reinhardtii cells produce two to 32 daughter cells by one to five divisions, depending on cellular growth in the G1 phase. By contrast, in this study, we found that Tetrabaena socialis and Gonium pectorale cells mostly produced four and eight daughter cells by two and three successive divisions, respectively. In contrast to C. reinhardtii, which is committed to cell division when the cell has grown two-fold, T. socialis and G. pectorale are committed only when the cells have grown four- and eight-fold, respectively. Thus, our results suggest that evolutionary changes in cellular size for commitment largely contributes to the emergence and evolution of multicellularity in volvocine algae.
- 著者
- Toshiyuki Takahashi Mayuko Sato Kiminori Toyooka Hisayoshi Nozaki
- 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.79, no.1, pp.119-123, 2014-03-25 (Released:2014-07-15)
- 参考文献数
- 18
- 被引用文献数
- 7 11
Cyanophora paradoxa is an enigmatic biflagellate that may represent the first photosynthetic eukaryote morphologically. This alga has been widely studied as a model organism of primitive phototrophs. However, surface ornamentations of the vegetative cells have not been examined using ultra-high resolution field emission (FE) scanning electron microscopy (SEM). In the present study, C. paradoxa NIES-547 vegetative cells were examined using FE-SEM and compared with the data using conventional SEM. Our FE-SEM images demonstrated that the cell surface was ornamented with angular fenestrations framed by ridges. In contrast, conventional SEM did not reveal similar surface ornamentation. Transmission electron microscopy showed the ridge was formed by the edges of overlapping or attaching outermost plate vesicles at the cell periphery.