Genome-wide identification of markers for activating and repressing enhancers in the Drosophila melanogaster embryo
Transcription factors are DNA-binding proteins, which are involved in the regulation of transcription, which in turn is fundamental for differential gene expression during development. Interestingly, transcription factors can both activate and repress transcription depending on the cellular context. It is unsolved, however, how they are able to facilitate both tasks and which cooperating proteins or histone modifications are reliable markers for activation or repression on a genome-wide level.
To address this question, genome-wide binding experiments (ChIP-seq) of various factors will be performed during the dorsoventral patterning in Drosophila embryos. The advantages of this system are that repression is extensively studied and that mutants are available in which the embryos consist of only one tissue type. Thus, it will be possible to analyze the genome-wide binding patterns of transcription factors at enhancers that mediate either repression or activation but not both.
The identification of proteins, which clearly distinguish between the two will help in the interpretation of genomics data and give insights into the mechanisms of transcriptional repression.