Pitt Logo LinkContact Us

Repression of Dpp targets in the Drosophila wing by Brinker

Winter, Stephanie E. (2005) Repression of Dpp targets in the Drosophila wing by Brinker. Doctoral Dissertation, University of Pittsburgh.

[img]
Preview
PDF - Primary Text
Download (10Mb) | Preview

    Abstract

    During development, gradients of transcription factors regulate patterning along a body axis by activation or repression of target genes above distinct threshold levels. In the Drosophila wing, expression of genes such as spalt (sal) and optomotor-blind (omb) is restricted along the A/P axis by lateral-to-medial gradients of the transcriptional repressor Brinker (Brk). sal is more sensitive to repression by Brk than omb, and thus has a narrower expression domain compared to omb. The Brk expression pattern is established by Decapentaplegic (Dpp), a TGF-b superfamily member, which forms a complementary medial-to-lateral morphogen gradient along the (A/P) axis of the wing. We have investigated the mechanisms Brk uses to repress gene expression to gain an understanding of why some targets such as sal are more sensitive to Brk than others such as omb. Previous studies have suggested that Brk represses gene expression simply by competing with activators, but we show that Brk requires an active repression domain along with the DNA binding domain for repressor activity. Brk possesses four repression domains, but these domains are not equivalent; for example, 3R is sufficient to repress omb but not sal. Consequently, although sal and omb show quantitative differences in their response to Brk, there are qualitative differences in the mechanisms that Brk uses to repress each of these genes.


    Share

    Citation/Export:
    Social Networking:

    Details

    Item Type: University of Pittsburgh ETD
    ETD Committee:
    ETD Committee TypeCommittee MemberEmail
    Committee ChairCampbell, Gerard Lcamp@pitt.edu
    Committee MemberLopez, A. Javierjlaa@andrew.cmu.edu
    Committee MemberStronach, Bethstronach@pitt.edu
    Committee MemberBrodsky, Jeffreyjbrodsky@pitt.edu
    Committee MemberGrabowski, Paula Jpag4@pitt.edu
    Title: Repression of Dpp targets in the Drosophila wing by Brinker
    Status: Unpublished
    Abstract: During development, gradients of transcription factors regulate patterning along a body axis by activation or repression of target genes above distinct threshold levels. In the Drosophila wing, expression of genes such as spalt (sal) and optomotor-blind (omb) is restricted along the A/P axis by lateral-to-medial gradients of the transcriptional repressor Brinker (Brk). sal is more sensitive to repression by Brk than omb, and thus has a narrower expression domain compared to omb. The Brk expression pattern is established by Decapentaplegic (Dpp), a TGF-b superfamily member, which forms a complementary medial-to-lateral morphogen gradient along the (A/P) axis of the wing. We have investigated the mechanisms Brk uses to repress gene expression to gain an understanding of why some targets such as sal are more sensitive to Brk than others such as omb. Previous studies have suggested that Brk represses gene expression simply by competing with activators, but we show that Brk requires an active repression domain along with the DNA binding domain for repressor activity. Brk possesses four repression domains, but these domains are not equivalent; for example, 3R is sufficient to repress omb but not sal. Consequently, although sal and omb show quantitative differences in their response to Brk, there are qualitative differences in the mechanisms that Brk uses to repress each of these genes.
    Date: 10 October 2005
    Date Type: Completion
    Defense Date: 25 July 2005
    Approval Date: 10 October 2005
    Submission Date: 15 August 2005
    Access Restriction: No restriction; Release the ETD for access worldwide immediately.
    Patent pending: No
    Institution: University of Pittsburgh
    Thesis Type: Doctoral Dissertation
    Refereed: Yes
    Degree: PhD - Doctor of Philosophy
    URN: etd-08152005-134633
    Uncontrolled Keywords: Brinker; Dpp; Drosophila; transcriptional repression
    Schools and Programs: Dietrich School of Arts and Sciences > Biological Sciences
    Date Deposited: 10 Nov 2011 14:59
    Last Modified: 20 Apr 2012 13:03
    Other ID: http://etd.library.pitt.edu/ETD/available/etd-08152005-134633/, etd-08152005-134633

    Actions (login required)

    View Item

    Document Downloads