当前位置： SCI文献检索 > JOURNAL OF BIOLOGICAL RHYTHMS期刊下所有文献 > Circadian photoreception in Drosophila: functions of cryptochrome in peripheral and central clocks.

Circadian photoreception in Drosophila: functions of cryptochrome in peripheral and central clocks.

Abstract：

:In Drosophila melanogaster, disruption of night by even short light exposures results in degradation of the clock protein TIMELESS (TIM), leading to shifts in the fly molecular and behavioral rhythms. Several lines of evidence indicate that light entrainment of the brain clock involves the blue-light photoreceptor cryptochrome (CRY). In cryptochrome-depleted Drosophila (cry(b)), the entrainment of the brain clock by short light pulses is impaired but the clock is still entrainable by light-dark cycles, probably due to light input from the visual system. Whether cryptochrome and visual transduction pathways play a role in entrainment of noninnervated, directly photosensitive peripheral clocks is not known and the subject of this study. The authors monitored levels of the clock protein TIM in the lateral neurons (LNs) of larval brains and in the renal Malpighian tubules (MTs) of flies mutant for the cryptochrome gene (cry(b)) and in mutants that lack signaling from the visual photopigments (norpA(P41)). In cry(b) flies, light applied during the dark period failed to induce degradation of TIM both in MTs and in LNs, yet attenuated cycling of TIM was observed in both tissues in LD. This cycling was abolished in LNs, but persisted in MTs, of norpA(P41);cry(b) double mutants. Furthermore, the activity of the tim gene in the MTs of cry(b) flies, reported by luciferase, seemed stimulated by lights-on and suppressed by lights-off, suggesting that the absence of functional cryptochrome uncovered an additional light-sensitive pathway synchronizing the expression of TIM in this tissue. In constant darkness, cycling of TIM was abolished in MTs; however, it persisted in LNs of cry(b) flies. The authors conclude that cryptochrome is involved in TIM-mediated entrainment of both central LN and peripheral MT clocks. Cryptochrome is also an indispensable component of the endogenous clock mechanism in the examined peripheral tissue, but not in the brain. Thus, although neural and epithelial cells share the core clock mechanism, some clock components and light-entrainment pathways appear to have tissue-specific roles.

journal_name

J Biol Rhythms

journal_title

Journal of biological rhythms

authors

Ivanchenko M,Stanewsky R,Giebultowicz JM

doi

10.1177/074873040101600303

subject

Has Abstract

pub_date

2001-06-01 00:00:00

pages

205-15

issue

eissn

0748-7304

issn

1552-4531

journal_volume

pub_type

杂志文章

在线工具

Circadian photoreception in Drosophila: functions of cryptochrome in peripheral and central clocks.