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Revision as of 16:15, 22 September 2012

Promoters

What's a Promoter?

Promoters have been defined as modulatory DNA structures, regulatoring initiation of transcription and for controlling expression of a gene. Promoters therefore induce, via protein synthesis, the specific role of tissue.

Indeed, the promoter is the region of the DNA where binds initially RNA polymerase before the start of RNA synthesis. This sequences are generally located upstream of the start site of transcription. Fixation and activation of RNA polymerase is controlled by transcription factors which may be either activators or repressors of transcription.

The organization of promoter sequences in the eukaryotes:

-Transcription factor-IIB (TFIIB) is one of several general transcription factors. That make up the RNA polymerase II preinitiation complex.

-The TATA-box is a DNA sequence (cis-regulatory element) found in the promoter area of genes in archaea and eukaryotes.

-The initiator element (Inr), sometimes Also called initiator pattern is a core promoter That is similar in function to the Pribnow box (for prokaryotes) or the TATA box (for eukaryotes). Similarly to the TATA box, the Inr element Facilitates the binding of transcription factor II D (TBP).

-The downstream promoter element-(DPE) is a core promoter Like all core promoters, the DPE plays significant role in the year initiation of gene transcription by RNA polymerase II.

Our Promoters Sytem

Concerning inter-tissue communication, the use of promoters quickly becomes evident to induce gene expression in a specific tissue. And each tissue acquires a special role in the scheme of communication.
The fallen of the use of inter-tissue communication within an organization such as Xenopus, suggest a tremendous opportunity for innovation, to build logic diagrams more complex.


About our communication system, we relied mainly on three promoters.

Specific Skeletal Muscle Expression

Promotor: pCarA




Sequence of promotor : link

Pancreas Expression

Promotor: pElastase

Sequence of promotor : link

Anti Heat-Shock System

Promotor: pHsp70

Sequence ofpromotor : link

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pCS2+ with RFP J04450

pCS2+ carracteristic

pCS2+, plasmid of 4095pb, contains :

• AmpR : An Ampicilin resistance gène ( link to sequence )
• ColE1 ori : Transcription and initiation of DNA replication in E.Coli
• F1 origin : Replication Origin
• Simian CMV IE94 Promoter : CMV eukariotic promoter to increase the transcription plasmid
• M13 R :
• lac operon :
• T3 promoter frag
• SV40 polyA :
• B-globin 5' mRNA sequence :
• Sp6 :
• T7 promoter frag :

RFP J04450

link name

Red/Whrite selection technique

With this plasmid construction, we can easely check and select before injection in the tadpole, if our insert is correctrly in pCS2+. Indeed, during de bacterial growing, if colonies are red, this part hasn't be added correctrly