TY - JOUR
T1 - Circadian oscillations outside the optic lobe in the cricket Gryllus bimaculatus
AU - Uryu, Outa
AU - Tomioka, Kenji
PY - 2010/9/1
Y1 - 2010/9/1
N2 - Although circadian rhythms are found in many peripheral tissues in insects, the control mechanism is still to be elucidated. To investigate the central and peripheral relationships in the circadian organization, circadian rhythms outside the optic lobes were examined in the cricket Gryllus bimaculatus by measuring mRNA levels of period (per) and timeless (tim) genes in the brain, terminal abdominal ganglion (TAG), anterior stomach, mid-gut, testis, and Malpighian tubules. Except for Malpighian tubules and testis, the tissues showed a daily rhythmic expression in either both per and tim or tim alone in LD. Under constant darkness, however, the tested tissues exhibited rhythmic expression of per and tim mRNAs, suggesting that they include a circadian oscillator. The amplitude and the levels of the mRNA rhythms varied among those rhythmic tissues. Removal of the optic lobe, the central clock tissue, differentially affected the rhythms: the anterior stomach lost the rhythm of both per and tim; in the mid-gut and TAG, tim expression became arrhythmic but per maintained rhythmic expression; a persistent rhythm with a shifted phase was observed for both per and tim mRNA rhythms in the brain. These data suggest that rhythms outside the optic lobe receive control from the optic lobe to different degrees, and that the oscillatory mechanism may be different from that of Drosophila.
AB - Although circadian rhythms are found in many peripheral tissues in insects, the control mechanism is still to be elucidated. To investigate the central and peripheral relationships in the circadian organization, circadian rhythms outside the optic lobes were examined in the cricket Gryllus bimaculatus by measuring mRNA levels of period (per) and timeless (tim) genes in the brain, terminal abdominal ganglion (TAG), anterior stomach, mid-gut, testis, and Malpighian tubules. Except for Malpighian tubules and testis, the tissues showed a daily rhythmic expression in either both per and tim or tim alone in LD. Under constant darkness, however, the tested tissues exhibited rhythmic expression of per and tim mRNAs, suggesting that they include a circadian oscillator. The amplitude and the levels of the mRNA rhythms varied among those rhythmic tissues. Removal of the optic lobe, the central clock tissue, differentially affected the rhythms: the anterior stomach lost the rhythm of both per and tim; in the mid-gut and TAG, tim expression became arrhythmic but per maintained rhythmic expression; a persistent rhythm with a shifted phase was observed for both per and tim mRNA rhythms in the brain. These data suggest that rhythms outside the optic lobe receive control from the optic lobe to different degrees, and that the oscillatory mechanism may be different from that of Drosophila.
KW - Circadian clock
KW - Clock gene
KW - Cricket
KW - Period
KW - Peripheral oscillator
KW - Timeless
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U2 - 10.1016/j.jinsphys.2010.04.010
DO - 10.1016/j.jinsphys.2010.04.010
M3 - Article
C2 - 20416318
AN - SCOPUS:77955174078
VL - 56
SP - 1284
EP - 1290
JO - Journal of Insect Physiology
JF - Journal of Insect Physiology
SN - 0022-1910
IS - 9
ER -