TY - JOUR
T1 - The clock gene cycle plays an important role in the circadian clock of the cricket Gryllus bimaculatus
AU - Uryu, Outa
AU - Karpova, Svetlana G.
AU - Tomioka, Kenji
N1 - Funding Information:
The authors are grateful to Tomoaki Sakamoto, Yuichi Kamae, Akira Matsumoto and Taishi Yoshii for their technical assistance and comments on the earlier version of the manuscript. This study was supported in part by grants from Japan Society for Promotion of Science to KT . OU is a JSPS Research Fellow.
PY - 2013/7
Y1 - 2013/7
N2 - To dissect the molecular oscillatory mechanism of the circadian clock in the cricket Gryllus bimaculatus, we have cloned a cDNA of the clock gene cycle (Gb'. cyc) and analyzed its structure and function. Gb'. cyc contains four functional domains, i.e. bHLH, PAS-A, PAS-B and BCTR domains, and is expressed rhythmically in light dark cycles, peaking at mid night. The RNA interference (RNAi) of Clock (Gb'. Clk) and period (Gb'. per) reduced the Gb'. cyc mRNA levels and abolished the rhythmic expression, suggesting that the rhythmic expression of Gb'. cyc is regulated by a mechanism including Gb'. Clk and Gb'. per. These features are more similar to those of mammalian orthologue of cyc (Bmal1) than those of Drosophila cyc. A single treatment with double-stranded RNA (dsRNA) of Gb'. cyc effectively knocked down the Gb'. cyc mRNA level and abolished its rhythmic expression. The cyc RNAi failed to disrupt the locomotor rhythm, but lengthened its free-running period in constant darkness (DD). It is thus likely that Gb'. cyc is involved in the circadian clock machinery of the cricket. The cyc RNAi crickets showed a rhythmic expression of Gb'. per and timeless (Gb'. tim) in the optic lobe in DD, explaining the persistence of the locomotor rhythm. Surprisingly, cyc RNAi revealed a rhythmic expression of Gb'. Clk in DD which is otherwise rather constitutively expressed in the optic lobe. These facts suggest that the cricket might have a unique clock oscillatory mechanism in which both Gb'. cyc and Gb'. Clk are rhythmically controlled and that under abundant expression of Gb'. cyc the rhythmic expression of Gb'. Clk may be concealed.
AB - To dissect the molecular oscillatory mechanism of the circadian clock in the cricket Gryllus bimaculatus, we have cloned a cDNA of the clock gene cycle (Gb'. cyc) and analyzed its structure and function. Gb'. cyc contains four functional domains, i.e. bHLH, PAS-A, PAS-B and BCTR domains, and is expressed rhythmically in light dark cycles, peaking at mid night. The RNA interference (RNAi) of Clock (Gb'. Clk) and period (Gb'. per) reduced the Gb'. cyc mRNA levels and abolished the rhythmic expression, suggesting that the rhythmic expression of Gb'. cyc is regulated by a mechanism including Gb'. Clk and Gb'. per. These features are more similar to those of mammalian orthologue of cyc (Bmal1) than those of Drosophila cyc. A single treatment with double-stranded RNA (dsRNA) of Gb'. cyc effectively knocked down the Gb'. cyc mRNA level and abolished its rhythmic expression. The cyc RNAi failed to disrupt the locomotor rhythm, but lengthened its free-running period in constant darkness (DD). It is thus likely that Gb'. cyc is involved in the circadian clock machinery of the cricket. The cyc RNAi crickets showed a rhythmic expression of Gb'. per and timeless (Gb'. tim) in the optic lobe in DD, explaining the persistence of the locomotor rhythm. Surprisingly, cyc RNAi revealed a rhythmic expression of Gb'. Clk in DD which is otherwise rather constitutively expressed in the optic lobe. These facts suggest that the cricket might have a unique clock oscillatory mechanism in which both Gb'. cyc and Gb'. Clk are rhythmically controlled and that under abundant expression of Gb'. cyc the rhythmic expression of Gb'. Clk may be concealed.
KW - Circadian clock
KW - Clock genes
KW - Cricket
KW - Cycle
KW - RNAi
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U2 - 10.1016/j.jinsphys.2013.04.011
DO - 10.1016/j.jinsphys.2013.04.011
M3 - Article
C2 - 23665334
AN - SCOPUS:84878353916
VL - 59
SP - 697
EP - 704
JO - Journal of Insect Physiology
JF - Journal of Insect Physiology
SN - 0022-1910
IS - 7
ER -