Ph.D. defense

pdf Ph.D. thesis (french)

Relationship between regulatory element organization, gene function and gene expression in Arabidopsis thaliana: toward the regulatory element annotation

Transcription factor binding sites are regulatory elements involved in gene expression regulation. The knowledge of promoter architecture is now possible due to genome annotation and transcriptomic data. Some regulatory elements are conserved at a precise location in promoters. We developed an approach to characterize such motifs in A. thaliana. This work led to the promoter cartography by the identification of 5105 over-represented motifs in proximal promoters.
The TATA-box is a regulatory element conserved within eukaryotes. The core-promoter where this element is expected has been thoroughly analysed. We identified a list of 15 functional variants of the TATA-box and a new class of regulatory elements that shares the TATA-box topological constraints: the TC-motifs. They are conserved in both A. thaliana and Oryza sativa and have not been observed in mammalian genomes. The A. thaliana genes containing a TC-motif are 18%. They are mainly expressed in specific experimental conditions. The TC-motifs might be involved in gene expression regulation. We observed that the 4 dinucleotides of the initiator element YR in A. thaliana are extended in 5'UTR. Associations between these regulatory elements may highlight a functional collaboration. The study of the functional characteristics of genes with a same regulatory elements organization might help in these elements functional annotation.

Keywords: Arabidopsis thaliana, promoter, transcription start site (TSS), regulatory element , transcription.

Doctoral School: From genomes to Organisms (GAO)
Evry University (France - 91)

When?

2009 December 11th
2 p.m.

Ph.D. board of examiners

Where?

URGV,
Bâtiment G2,
2, rue Gaston Crémieux,
CP5708,
91057 Evry cedex
How to get at URGV?