Fundamental properties of the circadian clock in Drosophila melanogaster: A molecular, behavioral, and genetic analysis.

Format:

Book

Thesis/Dissertation

Author/Creator:

Hunter-Ensor, Mary Melissa.

Contributor:

University of Pennsylvania.

Language:

English

Subjects (All):

Neurosciences.

Molecular biology.

0307.

0317.

Penn dissertations--Neuroscience.

Neuroscience--Penn dissertations.

Local Subjects:

Penn dissertations--Neuroscience.

Neuroscience--Penn dissertations.

0307.

0317.

Physical Description:

114 pages

Contained In:

Dissertation Abstracts International 58-07B.

System Details:

Mode of access: World Wide Web.

text file

Summary:

Virtually all organisms exhibit rhythmic behaviors that occur with a period of approximately twenty four hours, about the length of a day. Circadian behaviors are the product of an endogenous biological clock. Circadian rhythms in Drosophila depend on the appropriate regulation of at least two genes, period (per) and timeless (tim). Levels of per and tim RNA cycle with the same phase, and the two proteins interact directly. In addition the two proteins inhibit their own transcription, thus generating a regulatory loop. Work described in this thesis (1) addresses the mechanisms that generate the feedback loop and (2) explains how the endogenous clock synchronizes to a light/dark cycle. The first part of the thesis describes the partial characterization of one conserved domain of per that participates in the per feedback loop. Deletion of this domain disrupts the expression of behavioral and molecular rhythms in Drosophila. The effects of this deletion on molecular rhythms suggest that the deletion perturbs PER's ability to negatively regulate its own transcription, possibly by compromising PER's ability to bind and repress a transcriptional activator. Feedback loops are a common mechanism used by many diverse organisms to generate circadian behaviors. Insights gained into the generation of the per feedback loop may suggest conserved mechanisms used to generate circadian behaviors in higher organisms as well. The second part of the thesis demonstrates that TIM mediates light-induced resetting of the circadian clock. TIM is degraded in response to light, and that this acute response resets the clock. Characterizing tim's role in light resetting may advance our understanding of phototransduction and circadian clock function.

Notes:

Thesis (Ph.D. in Neuroscience) -- University of Pennsylvania, 1997.

Source: Dissertation Abstracts International, Volume: 58-07, Section: B, page: 3490.

Local Notes:

School code: 0175.

ISBN:

9780591501926

Access Restriction:

Restricted for use by site license.