Barack Cohen, PhD
Dept. of Genetics
Washington University School of Medicine
St. Louis, MO
Brief Abstract: Large mammalian genomes contain millions of copies of the short, degenerate sequence motifs that recognize sequence specific DNA binding proteins. However, data from large scale studies of transcription factor binding studies show that only 1 in every 1000 potential sites are occupied in vivo. How is this specificity achieved. Two hypotheses have been put forward to explain this observation. One hypothesis states that the chromatin environment plays an instructive role in determining which transcription factor binding sites are bound and which are ignored. A second hypothesis is that local primary DNA sequence features distinguish functional from non-functional sites. I will discuss experiments in our lab that aim to distinguish between these two hypotheses.