RNA interference of timeless gene does not disrupt circadian locomotor rhythms in the cricket Gryllus bimaculatus

Yoshiki Danbara, Tomoaki Sakamoto, Outa Uryu, Kenji Tomioka

Research output: Contribution to journalArticle

30 Citations (Scopus)

Abstract

Molecular studies revealed that autoregulatory negative feedback loops consisting of so-called " clock genes" constitute the circadian clock in Drosophila. However, this hypothesis is not fully supported in other insects and is thus to be examined. In the cricket Gryllus bimaculatus, we have previously shown that period (per) plays an essential role in the rhythm generation. In the present study, we cloned cDNA of the clock gene timeless (tim) and investigated its role in the cricket circadian oscillatory mechanism using RNA interference. Molecular structure of the cricket tim has rather high similarity to those of other insect species. Real-time RT-PCR analysis revealed that tim mRNA showed rhythmic expression in both LD and DD similar to that of per, peaking during the (subjective) night. When injected with tim double-stranded RNA (ds. tim), tim mRNA levels were significantly reduced and its circadian expression rhythm was eliminated. After the ds. tim treatment, however, adult crickets showed a clear locomotor rhythm in DD, with a free-running period significantly shorter than that of control crickets injected with Discosoma sp. Red2 (DsRed2) dsRNA. These results suggest that in the cricket, tim plays some role in fine-tuning of the free-running period but may not be essential for oscillation of the circadian clock.

Original languageEnglish
Pages (from-to)1738-1745
Number of pages8
JournalJournal of Insect Physiology
Volume56
Issue number12
DOIs
Publication statusPublished - Dec 2010

Fingerprint

Gryllidae
Gryllus bimaculatus
Circadian Rhythm
RNA Interference
RNA interference
Genes
Circadian Clocks
genes
double-stranded RNA
circadian rhythm
Insects
Messenger RNA
insects
Double-Stranded RNA
Molecular Structure
chemical structure
Drosophila
oscillation
Real-Time Polymerase Chain Reaction
Complementary DNA

Keywords

  • Circadian clock
  • Clock gene
  • Cricket
  • Oscillatory mechanism
  • Period
  • RNAi
  • Timeless

ASJC Scopus subject areas

  • Insect Science
  • Physiology

Cite this

RNA interference of timeless gene does not disrupt circadian locomotor rhythms in the cricket Gryllus bimaculatus. / Danbara, Yoshiki; Sakamoto, Tomoaki; Uryu, Outa; Tomioka, Kenji.

In: Journal of Insect Physiology, Vol. 56, No. 12, 12.2010, p. 1738-1745.

Research output: Contribution to journalArticle

@article{866e3e1163224becaef72819c5c36e69,
title = "RNA interference of timeless gene does not disrupt circadian locomotor rhythms in the cricket Gryllus bimaculatus",
abstract = "Molecular studies revealed that autoregulatory negative feedback loops consisting of so-called {"} clock genes{"} constitute the circadian clock in Drosophila. However, this hypothesis is not fully supported in other insects and is thus to be examined. In the cricket Gryllus bimaculatus, we have previously shown that period (per) plays an essential role in the rhythm generation. In the present study, we cloned cDNA of the clock gene timeless (tim) and investigated its role in the cricket circadian oscillatory mechanism using RNA interference. Molecular structure of the cricket tim has rather high similarity to those of other insect species. Real-time RT-PCR analysis revealed that tim mRNA showed rhythmic expression in both LD and DD similar to that of per, peaking during the (subjective) night. When injected with tim double-stranded RNA (ds. tim), tim mRNA levels were significantly reduced and its circadian expression rhythm was eliminated. After the ds. tim treatment, however, adult crickets showed a clear locomotor rhythm in DD, with a free-running period significantly shorter than that of control crickets injected with Discosoma sp. Red2 (DsRed2) dsRNA. These results suggest that in the cricket, tim plays some role in fine-tuning of the free-running period but may not be essential for oscillation of the circadian clock.",
keywords = "Circadian clock, Clock gene, Cricket, Oscillatory mechanism, Period, RNAi, Timeless",
author = "Yoshiki Danbara and Tomoaki Sakamoto and Outa Uryu and Kenji Tomioka",
year = "2010",
month = "12",
doi = "10.1016/j.jinsphys.2010.07.002",
language = "English",
volume = "56",
pages = "1738--1745",
journal = "Journal of Insect Physiology",
issn = "0022-1910",
publisher = "Elsevier Limited",
number = "12",

}

TY - JOUR

T1 - RNA interference of timeless gene does not disrupt circadian locomotor rhythms in the cricket Gryllus bimaculatus

AU - Danbara, Yoshiki

AU - Sakamoto, Tomoaki

AU - Uryu, Outa

AU - Tomioka, Kenji

PY - 2010/12

Y1 - 2010/12

N2 - Molecular studies revealed that autoregulatory negative feedback loops consisting of so-called " clock genes" constitute the circadian clock in Drosophila. However, this hypothesis is not fully supported in other insects and is thus to be examined. In the cricket Gryllus bimaculatus, we have previously shown that period (per) plays an essential role in the rhythm generation. In the present study, we cloned cDNA of the clock gene timeless (tim) and investigated its role in the cricket circadian oscillatory mechanism using RNA interference. Molecular structure of the cricket tim has rather high similarity to those of other insect species. Real-time RT-PCR analysis revealed that tim mRNA showed rhythmic expression in both LD and DD similar to that of per, peaking during the (subjective) night. When injected with tim double-stranded RNA (ds. tim), tim mRNA levels were significantly reduced and its circadian expression rhythm was eliminated. After the ds. tim treatment, however, adult crickets showed a clear locomotor rhythm in DD, with a free-running period significantly shorter than that of control crickets injected with Discosoma sp. Red2 (DsRed2) dsRNA. These results suggest that in the cricket, tim plays some role in fine-tuning of the free-running period but may not be essential for oscillation of the circadian clock.

AB - Molecular studies revealed that autoregulatory negative feedback loops consisting of so-called " clock genes" constitute the circadian clock in Drosophila. However, this hypothesis is not fully supported in other insects and is thus to be examined. In the cricket Gryllus bimaculatus, we have previously shown that period (per) plays an essential role in the rhythm generation. In the present study, we cloned cDNA of the clock gene timeless (tim) and investigated its role in the cricket circadian oscillatory mechanism using RNA interference. Molecular structure of the cricket tim has rather high similarity to those of other insect species. Real-time RT-PCR analysis revealed that tim mRNA showed rhythmic expression in both LD and DD similar to that of per, peaking during the (subjective) night. When injected with tim double-stranded RNA (ds. tim), tim mRNA levels were significantly reduced and its circadian expression rhythm was eliminated. After the ds. tim treatment, however, adult crickets showed a clear locomotor rhythm in DD, with a free-running period significantly shorter than that of control crickets injected with Discosoma sp. Red2 (DsRed2) dsRNA. These results suggest that in the cricket, tim plays some role in fine-tuning of the free-running period but may not be essential for oscillation of the circadian clock.

KW - Circadian clock

KW - Clock gene

KW - Cricket

KW - Oscillatory mechanism

KW - Period

KW - RNAi

KW - Timeless

UR - http://www.scopus.com/inward/record.url?scp=77958463575&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=77958463575&partnerID=8YFLogxK

U2 - 10.1016/j.jinsphys.2010.07.002

DO - 10.1016/j.jinsphys.2010.07.002

M3 - Article

VL - 56

SP - 1738

EP - 1745

JO - Journal of Insect Physiology

JF - Journal of Insect Physiology

SN - 0022-1910

IS - 12

ER -