Michelle Wang of Cornell University spoke during the morning session of the Keystone Symposium on chromatin regulation in Taos, New Mexico today. She described her research focused on understanding how nucleosomes behave when they are pulled apart upstream the moving transcription machinery. This is like investigating how a train moves along a track when the track is tied up in knots. The train is the polymerase (transcription machinery) and the track is the DNA. She does this work by using amazingly delicate single molecule studies. By trapping either end of a stand of DNA with nucleosomes assembled and then physically pulling on one side she can observe the corresponding force curve which gives a readout of how strong or weak the histone/DNA interactions are during the pulling event.
I have described the optical tweezing technique for studying single DNA stands on this blog before.
There is also a great summary of her lab's research here.
Hall MA, Shundrovsky A, Bai L, Fulbright RM, Lis JT, & Wang MD (2009). High-resolution dynamic mapping of histone-DNA interactions in a nucleosome. Nature structural & molecular biology, 16 (2), 124-9 PMID: 19136959