- 著者
- Keiko Kobayashi Kae Akita Masashi Suzuki Daisaku Ohta Noriko Nagata
- 出版者
- Japanese Society for Plant Biotechnology
- 雑誌
- Plant Biotechnology (ISSN:13424580)
- 巻号頁・発行日
- vol.38, no.1, pp.109-116, 2021-03-25 (Released:2021-03-25)
- 参考文献数
- 35
- 被引用文献数
- 4
The exine acts as a protectant of the pollen from environmental stresses, and the pollen coat plays an important role in the attachment and recognition of the pollen to the stigma. The pollen coat is made of lipidic organelles in the tapetum. The pollen coat is necessary for fertility, as pollen coat-less mutants, such as those deficient in sterol biosynthesis, show severe male sterility. In contrast, the exine is made of sporopollenin precursors that are biosynthesized in the tapetum. Some mutants involved in sporopollenin biosynthesis lose the exine but show the fertile phenotype. One of these mutants, cyp704b1, was reported to lose not only the exine but also the pollen coat. To identify the cause of the fertile phenotype of the cyp704b1 mutant, the detailed structures of the tapetum tissue and pollen surface in the mutant were analyzed. As a result, the cyp704b1 mutant completely lost the normal exine but had high-electron-density granules localized where the exine should be present. Furthermore, normal lipidic organelles in the tapetum and pollen coat embedded between high-electron-density granules on the pollen surface were observed, unlike in a previous report, and the pollen coat was attached to the stigma. Therefore, the pollen coat is necessary for fertility, and the structure that functions like the exine, such as high-electron-density granules, on the pollen surface may play important roles in retaining the pollen coat in the cyp704b1 mutant.
- 著者
- Takumi Higaki Aya Kato Fumiyoshi Myouga Natsumaro Kutsuna Seiichiro Hasezawa Noriko Nagata
- 出版者
- 日本バイオイメージング学会
- 雑誌
- bioimages (ISSN:09192719)
- 巻号頁・発行日
- vol.22, pp.1-7, 2014 (Released:2015-06-30)
- 参考文献数
- 12
Recent advances in bioimaging equipment have allowed for the significant and rapid acquisition of biological images. Consequently, new methods are energetically being developed to quantitatively and objectively evaluate the biological features of many bioimages. Recently, we described the application of the CARTA (Clustering-Aided Rapid Training Agent) image classification framework, which can be used to obtain highly accurate classifications of a wide variety of biomedical images. However, the efficacy of this technology in association with transmission electron microscopy (TEM) images has not been evaluated. We herein report the automatic classification of chloroplast TEM images of chloroplasts of wild-type Arabidopsis thaliana and four kinds of mutants impaired in chloroplast-targeted proteins. CARTA successfully classified the TEM images based on their genetic backgrounds. As previously reported with fluorescent microscopic and magnetic resonance images, CARTA reduced the annotation cost while maintaining accuracy. Furthermore, using images obtained with different accelerating voltages resulted in biologically meaningless classifications, suggesting that TEM settings are critical for chloroplast morphological classification. CARTA is expected to be useful for future computational inspections of the ultrastructure visualized with TEM.
- 著者
- Tsuyoshi Ogata Yoshinao Yamazaki Nobuhiko Okabe Yosikazu Nakamura Masato Tashiro Noriko Nagata Shigeyuki Itamura Yoshinori Yasui Kazutoshi Nakashima Mikio Doi Youko Izumi Takashi Fujieda Shin'ichi Yamato Yuichi Kawada
- 出版者
- Japan Epidemiological Association
- 雑誌
- Journal of Epidemiology (ISSN:09175040)
- 巻号頁・発行日
- pp.0807040024, (Released:2008-07-07)
- 参考文献数
- 20
- 被引用文献数
- 28 30
Background: H5N2 avian influenza virus infection of humans has not been reported thus far. The first H5N2 avian influenza infection of poultry in Japan occurred in Ibaraki. Methods: The subjects were workers at 35 chicken farms in Ibaraki Prefecture, where the H5N2 virus or antibody was isolated from chickens. None of the subjects exhibited influenza symptoms. The H5N2-neutralizing antibody titers of the first and second paired sera samples were compared. To investigate the possible factors for this increase, the H5N2-neutralizing antibody titer (1:40 or more) was calculated for the second samples. A logistic regression analysis was performed to examine the association of these factors with H5N2-neutralizing antibody positivity. Results: We performed Wilcoxon matched-pairs signed-ranked test on data collected from 257 subjects, and determined that the H5N2 antibody titers of the second paired sera samples were significantly higher than those of the first samples (P < 0.001). The H5N2 antibody titers of paired sera of 13 subjects without a history of seasonal influenza vaccination within the previous 12 months increased 4-fold or more. The percentage of antibody positivity was 32% for subjects with a history of seasonal influenza vaccination (28% of all subjects) and 13% for those without a history of the same. The adjusted odds ratio of H5N2-neutralizing antibody positivity was 4.6 (95% confidence interval: 1.6-13.7) for those aged over 40 and 3.1 (95% confidence interval: 1.6-6.1) for those with a history of seasonal influenza vaccination within the previous 12 months. Conclusion: The results suggest that this may have been the first avian influenza H5N2 infection of poultry to affect humans. A history of seasonal influenza vaccination might be associated with H5N2-neutralizing antibody positivity.