Lecture 21 & 22

Anterior repression of eve stripe 2 enhancer requires three position-specific mechanisms

   My aim over the last four lectures was to demonstrate the complexity of a developmentally regulated enhancer and to give you a sense of how enhancers work.  Many of the important concepts illustrated for the eve stripe 2 enhancer are common features to a wide variety of enhancers. 

    Today's lecture concludes our investigation into the function of the eve stripe 2 enhancer.  We will be discussing the following paper:

Andrioli LP, Vasisht V, Theodosopoulou E, Oberstein A, Small S.  Anterior repression of a Drosophila stripe enhancer requires three position-specific mechanisms.  Development 2002 Nov;129(21):4931-40.

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We will conclude our investigation into the mechanism of eve stripe 2 regulation with a class discussion about what experiments need to done next.

Notes added after lecture:

1.  Conduct similar experiments on the other eve stripe enhancers; determine mode of action of other stripe elements.

2.  Identify the other factors (activators and repressors) involved in the regulation of eve stripe 2.  Biochemical and genetic approaches were discussed.

3.  Determine mechanism of action of Giant?  How does short range repression work?  Is it through chromatin effects?  Does Giant modify Bcd?  Find Gt-interacting proteins as these may tell you something about Gt function.

4.  How does the eve stripe 2 enhancer communicate with the promoter?  RNA TRAP experiments would reveal if DNA looping is involved.  Yeast two hybrid experiments using Bcd or Hb as bait to look for protein-protein interactions with general transcription factors.