Wednesday, June 29, 2011

Substantial Histone Reduction Modulates Genome-wide Nucleosomal Occupancy and Global Transcriptional Output

The recent wave of publications seem to continue, and another paper just appeared in PLoS Biology. Like the previous one, this one was in the reviewing rounds for very long, and so we are very happy that it finally appeared.

This project is a collaboration with the group of Alessandra Agresti and Marco Bianchi from San Raffaele University in Milan. They are part of a European consortium that we are also members of, and they approached us to get help on dealing with nucleosome organization. Assaf got involved, into what was dubbed "The Italian Job" in lab meeting. After almost two years, the result is an impressive article.

To summarize the basic idea, the experiments by Barbara Celona, the main author, and other member's of the Milan group show that deletion in a key gene reduces the number of nucleosomes in the genome. As a result the DNA strands are packed by smaller number of nucleosomes. By mapping the locations of these nucleosomes we can see if nucleosome reduction leads to uniform change in density, or preferential reduction at particular locations, and what is the effect on transcription.

Source: PLoS Biology Synopsis by Robin Mejia

Our results show that nucleosome loss is mostly in locations that are less packed in normal cells, and moreover, that this loss correlates with increased transcription.


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