TY - JOUR
T1 - Peripheral circadian clock for the cuticle deposition rhythm in Drosophila melanogaster
AU - Ito, Chihiro
AU - Goto, Shin G.
AU - Shiga, Sakiko
AU - Tomioka, Kenji
AU - Numata, Hideharu
PY - 2008/6/17
Y1 - 2008/6/17
N2 - Insect endocuticle thickens after adult emergence by daily alternating deposition of two chitin layers with different orientation. Although the cuticle deposition rhythm is known to be controlled by a circadian clock in many insects, the site of the driving clock, the photoreceptor for entrainment, and the oscillatory mechanism remain elusive. Here, we show that the cuticle deposition rhythm is regulated by a peripheral oscillator in the epidermis in Drosophila melanogaster. Free-running and entrainment experiments in vitro reveal that the oscillator for the cuticle deposition rhythm is independent of the central clock in the brain driving the locomotor rhythms. The cuticle deposition rhythm is absent in null and dominant-negative mutants of clock genes (i.e., period, timeless, cycle, and Clock), indicating that this oscillator is composed of the same clock genes as the central clock. Entrainment experiments with monochromatic light-dark cycles and cryb flies reveal that a blue light-absorbing photoreceptor, cryptochrome (CRY), acts as a photoreceptor pigment for the entrainment of the cuticle deposition rhythm. Unlike other peripheral rhythms in D. melanogaster, the cuticle deposition rhythm persisted in cryb and cryOUT mutant flies, indicating that CRY does not play a core role in the rhythm generation in the epidermal oscillator.
AB - Insect endocuticle thickens after adult emergence by daily alternating deposition of two chitin layers with different orientation. Although the cuticle deposition rhythm is known to be controlled by a circadian clock in many insects, the site of the driving clock, the photoreceptor for entrainment, and the oscillatory mechanism remain elusive. Here, we show that the cuticle deposition rhythm is regulated by a peripheral oscillator in the epidermis in Drosophila melanogaster. Free-running and entrainment experiments in vitro reveal that the oscillator for the cuticle deposition rhythm is independent of the central clock in the brain driving the locomotor rhythms. The cuticle deposition rhythm is absent in null and dominant-negative mutants of clock genes (i.e., period, timeless, cycle, and Clock), indicating that this oscillator is composed of the same clock genes as the central clock. Entrainment experiments with monochromatic light-dark cycles and cryb flies reveal that a blue light-absorbing photoreceptor, cryptochrome (CRY), acts as a photoreceptor pigment for the entrainment of the cuticle deposition rhythm. Unlike other peripheral rhythms in D. melanogaster, the cuticle deposition rhythm persisted in cryb and cryOUT mutant flies, indicating that CRY does not play a core role in the rhythm generation in the epidermal oscillator.
KW - Circadian rhythm
KW - Clock genes
KW - Cryptochrome
KW - Entrainment
KW - Epidermal cell
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U2 - 10.1073/pnas.0800145105
DO - 10.1073/pnas.0800145105
M3 - Article
C2 - 18539772
AN - SCOPUS:46149100504
VL - 105
SP - 8446
EP - 8451
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
SN - 0027-8424
IS - 24
ER -