GSBS Student Publications


Ectopic CRYPTOCHROME renders TIM light sensitive in the Drosophila ovary

Student Author(s)

Alejandro Murad

GSBS Program


Publication Date


UMMS Affiliation

Department of Neurobiology; Emery Lab; Graduate School of Biomedical Sciences, Neuroscience Program

Document Type



Neuroscience and Neurobiology


The period (per) and timeless (tim) genes play a central role in the Drosophila circadian clock mechanism. PERIOD (PER) and TIMELESS (TIM) proteins periodically accumulate in the nuclei of pace-making cells in the fly brain and many cells in peripheral organs. In contrast, TIM and PER in the ovarian follicle cells remain cytoplasmic and do not show daily oscillations in their levels. Moreover, TIM is not light sensitive in the ovary, while it is highly sensitive to this input in circadian tissues. The mechanism underlying this intriguing difference is addressed here. It is demonstrated that the circadian photoreceptor CRYPTOCHROME (CRY) is not expressed in ovarian tissues. Remarkably, ectopic cry expression in the ovary is sufficient to cause degradation of TIM after exposure to light. In addition, PER levels are reduced in response to light when CRY is present, as observed in circadian cells. Hence, CRY is the key component of the light input pathway missing in the ovary. However, the factors regulating PER and TIM levels downstream of light/cry action appear to be present in this non-circadian organ.

DOI of Published Version



J Biol Rhythms. 2006 Aug;21(4):272-8. Link to article on publisher's site

Journal/Book/Conference Title

Journal of biological rhythms

Related Resources

Link to Article in PubMed

PubMed ID