2020年12月
The role of clockwork orange in the circadian clock of the cricket Gryllus bimaculatus
Zoological Letters
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- 巻
- 6
- 号
- 1
- 記述言語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1186/s40851-020-00166-4
- 出版者・発行元
- Springer Science and Business Media LLC
<title>Abstract</title>
The circadian clock generates rhythms of approximately 24 h through periodic expression of the clock genes. In insects, the major clock genes <italic>period</italic> (<italic>per</italic>) and <italic>timeless</italic> (<italic>tim</italic>) are rhythmically expressed upon their transactivation by CLOCK/CYCLE, with peak levels in the early night. In <italic>Drosophila</italic>, <italic>clockwork orange</italic> (<italic>cwo</italic>) is known to inhibit the transcription of <italic>per</italic> and <italic>tim</italic> during the daytime to enhance the amplitude of the rhythm, but its function in other insects is largely unknown. In this study, we investigated the role of <italic>cwo</italic> in the clock mechanism of the cricket <italic>Gryllus bimaculatus</italic>. The results of quantitative RT-PCR showed that under a light/dark (LD) cycle, <italic>cwo</italic> is rhythmically expressed in the optic lobe (lamina-medulla complex) and peaks during the night. When <italic>cwo</italic> was knocked down via RNA interference (RNAi), some crickets lost their locomotor rhythm, while others maintained a rhythm but exhibited a longer free-running period under constant darkness (DD). In <italic>cwo</italic>RNAi crickets, all clock genes except for <italic>cryptochrome 2</italic> (<italic>cry2</italic>) showed arrhythmic expression under DD; under LD, some of the clock genes showed higher mRNA levels, and <italic>tim</italic> showed rhythmic expression with a delayed phase. Based on these results, we propose that <italic>cwo</italic> plays an important role in the cricket circadian clock.
The circadian clock generates rhythms of approximately 24 h through periodic expression of the clock genes. In insects, the major clock genes <italic>period</italic> (<italic>per</italic>) and <italic>timeless</italic> (<italic>tim</italic>) are rhythmically expressed upon their transactivation by CLOCK/CYCLE, with peak levels in the early night. In <italic>Drosophila</italic>, <italic>clockwork orange</italic> (<italic>cwo</italic>) is known to inhibit the transcription of <italic>per</italic> and <italic>tim</italic> during the daytime to enhance the amplitude of the rhythm, but its function in other insects is largely unknown. In this study, we investigated the role of <italic>cwo</italic> in the clock mechanism of the cricket <italic>Gryllus bimaculatus</italic>. The results of quantitative RT-PCR showed that under a light/dark (LD) cycle, <italic>cwo</italic> is rhythmically expressed in the optic lobe (lamina-medulla complex) and peaks during the night. When <italic>cwo</italic> was knocked down via RNA interference (RNAi), some crickets lost their locomotor rhythm, while others maintained a rhythm but exhibited a longer free-running period under constant darkness (DD). In <italic>cwo</italic>RNAi crickets, all clock genes except for <italic>cryptochrome 2</italic> (<italic>cry2</italic>) showed arrhythmic expression under DD; under LD, some of the clock genes showed higher mRNA levels, and <italic>tim</italic> showed rhythmic expression with a delayed phase. Based on these results, we propose that <italic>cwo</italic> plays an important role in the cricket circadian clock.
- リンク情報
- ID情報
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- DOI : 10.1186/s40851-020-00166-4
- eISSN : 2056-306X