- 著者
- Masayoshi Sano Ryosuke Makabe Ryo Matsuda Norio Kurosawa Masato Moteki
- 出版者
- The Plankton Society of Japan, The Japanese Association of Benthology
- 雑誌
- Plankton and Benthos Research (ISSN:18808247)
- 巻号頁・発行日
- vol.17, no.4, pp.349-357, 2022-11-30 (Released:2022-11-30)
- 参考文献数
- 37
Molecular analysis is a common tool for marine ecological and biological research. For genomic analysis of zooplankton, ethanol preservation and freezing are often used to preserve samples until analysis. However, these methods have disadvantages, such as the loss of morphological information. Recently, 10% Lugol’s iodine solution (10% Lugol) has been shown to be an effective preservative of plankton samples for molecular analysis, even after 18 months. However, that study only reported a PCR-based molecular study using copepods. We tested the preservation effectiveness of 10% Lugol on various zooplankton over 33 months by comparing them to samples preserved by freezing or in 5% formalin seawater. The results revealed that the total amounts of DNA extracted from crustacean and gelatinous zooplankton preserved in 10% Lugol were the same or higher than those preserved in formalin or by freezing. Gel electrophoresis of the extracted DNA indicated that the DNA of the samples preserved in 10% Lugol was not fragmented during the preservation period. PCR amplification of a partial 18S rRNA gene using DNA extracted from various zooplankton taxa (siphonophores, copepods, ostracods, doliolids, polychaetes, pteropods, euphausiids, and chaetognaths) was successful. Sequences of morphologically identified species preserved in 10% Lugol had BLAST hits to sequences of these species deposited in Genbank, with a similarity of 100%, which indicated there was no sequence alteration during the preservation period. Thus, we conclude that 10% Lugol is a suitable preservative for molecular analysis of various zooplankton taxonomic groups.
- 著者
- Kazuhiro FUJIWARA Shunsuke KUBO Kensuke EIJIMA Ryo MATSUDA Akira YANO
- 出版者
- The Society of Agricultural Meteorology of Japan
- 雑誌
- 農業気象 (ISSN:00218588)
- 巻号頁・発行日
- vol.78, no.3, pp.101-112, 2022-07-10 (Released:2022-07-10)
- 参考文献数
- 26
We have improved a light-emitting diode artificial sunlight source system that we developed in 2013. The 2013 system can produce light with various spectral distributions for wavelengths of 380-940 nm that approximates those of ground-level sunlight and produce light with arbitrarily modified spectral distributions. Moreover, this system can produce time-varying light with different spectral distributions. However, this system’s utility is limited because the light it produces has low maximum irradiance and low time-stability for sunlight-effect research experiments. Hardware and software improvements to that system allow it to now produce a maximum irradiance of approximately 1.54 kW m-2 for 380-940 nm at a 7.1 cm2 light outlet with greater time stability and make it easier to produce time-varying light having a large number of different spectral distributions. First-step operational tests showed that this improved system can accurately produce single light with spectral irradiance distributions (SIDs) approximating: (1) SIDs of ground-level sunlight measured in Tokyo at two-hour intervals on a clear day; (2) various magnifications (1.33, 1.2, 1, 1/10, 1/100, and 1/1000 times) of a reference terrestrial solar SID, which is defined by the International Electrotechnical Commission; and (3) various geometric-shape SIDs as arbitrarily modified ones, except for a rectangular shape. For the second-step operational test, time-varying light with the three SIDs described above was produced in various sequences at three-second intervals. The third-step operational test verified the 30-min time stability of SID at the light outlet. Operational tests indicate that the improved system can facilitate various sunlight-effect research. Our improved system enables sunlight-effect research experiments that were previously impossible, such as investigations of naturally fluctuating sunlight effects on plant response, growth, and development. Moreover, experiments comparing the effects of ground-level sunlight spectral distribution and conventional artificial lamps on plant growth and development are now possible.