TY - JOUR
T1 - The role of clockwork orange in the circadian clock of the cricket Gryllus bimaculatus
AU - Tomiyama, Yasuaki
AU - Shinohara, Tsugumichi
AU - Matsuka, Mirai
AU - Bando, Tetsuya
AU - Mito, Taro
AU - Tomioka, Kenji
N1 - Funding Information:
This study was supported by the Japan Society for Promotion of Science (JSPS) Grants-in-Aid for Scientific Research No. JP15H04400 and JP18H02480 to KT. Acknowledgments
Publisher Copyright:
© 2020, The Author(s).
PY - 2020/12
Y1 - 2020/12
N2 - The circadian clock generates rhythms of approximately 24 h through periodic expression of the clock genes. In insects, the major clock genes period (per) and timeless (tim) are rhythmically expressed upon their transactivation by CLOCK/CYCLE, with peak levels in the early night. In Drosophila, clockwork orange (cwo) is known to inhibit the transcription of per and tim 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 cwo in the clock mechanism of the cricket Gryllus bimaculatus. The results of quantitative RT-PCR showed that under a light/dark (LD) cycle, cwo is rhythmically expressed in the optic lobe (lamina-medulla complex) and peaks during the night. When cwo 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 cwoRNAi crickets, all clock genes except for cryptochrome 2 (cry2) showed arrhythmic expression under DD; under LD, some of the clock genes showed higher mRNA levels, and tim showed rhythmic expression with a delayed phase. Based on these results, we propose that cwo plays an important role in the cricket circadian clock.
AB - The circadian clock generates rhythms of approximately 24 h through periodic expression of the clock genes. In insects, the major clock genes period (per) and timeless (tim) are rhythmically expressed upon their transactivation by CLOCK/CYCLE, with peak levels in the early night. In Drosophila, clockwork orange (cwo) is known to inhibit the transcription of per and tim 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 cwo in the clock mechanism of the cricket Gryllus bimaculatus. The results of quantitative RT-PCR showed that under a light/dark (LD) cycle, cwo is rhythmically expressed in the optic lobe (lamina-medulla complex) and peaks during the night. When cwo 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 cwoRNAi crickets, all clock genes except for cryptochrome 2 (cry2) showed arrhythmic expression under DD; under LD, some of the clock genes showed higher mRNA levels, and tim showed rhythmic expression with a delayed phase. Based on these results, we propose that cwo plays an important role in the cricket circadian clock.
KW - Circadian clock
KW - Clock gene
KW - Clockwork orange
KW - Cricket
KW - Locomotor rhythm
KW - Molecular oscillation
KW - cry2
UR - http://www.scopus.com/inward/record.url?scp=85095820489&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85095820489&partnerID=8YFLogxK
U2 - 10.1186/s40851-020-00166-4
DO - 10.1186/s40851-020-00166-4
M3 - Article
AN - SCOPUS:85095820489
SN - 2056-306X
VL - 6
JO - Zoological Letters
JF - Zoological Letters
IS - 1
M1 - 12
ER -