Epigenomics: A Roadmap to Chromatin

Abstract

In their Letter “Epigenomics: a roadmap, but to where?” (3 October, p. 43), H. D. Madhani et al. applaud the NIH for directing funds towards chromatin research, but argue that the Epigenomics Roadmap initiative ([1][1]) is ill-conceived and diverts funds from investigator- initiated proposals. However, their criticisms are more semantic than scientific, and they ignore the role that technology development has played in driving chromatin research. As recipients of grants awarded in this program, we would like to set the record straight. ![Figure][2] CREDIT: JUPITER IMAGES We agree with Madhani et al. that epigenetic regulation is driven by transcription factor binding. However, studies of such regulatory processes have traditionally received strong NIH support, whereas the Epigenomics Roadmap aims to characterize the chromatin landscape that transcription factors act upon. Unlike transcription factors, which are diverse and often differ between eukaryotic taxa, chromatin components include histone variants and modifications that are essentially universal. Ultimately, transcription factors must act upon DNA packaged by histones, and essentially all eukaryotes use a common set of histone and DNA modifying enzymes, nucleosome remodelers, histone chaperones, and chromatin-binding proteins to facilitate transcription factor and polymerase action. We think that the NIH is justified in limiting this initiative to chromatin, and had some other term than “epigenomics” been used, there would be no basis for this complaint. A more substantive concern is that this initiative diverts funds from investigator-initiated grants, corralling individual scientists “to work together under a more rigid, directed framework.” However, 17 of the 22 grantees aim to develop novel tools and markers for chromatin research. Our three grants are high-risk, high-gain R21s; at $175,000 to $200,000 per year for 2 years, they are among the smallest NIH awards. Although we recognize that these funds might have been diverted from traditional programs of the NIH institutes that fund us (the National Institute on Drug Abuse, the National Institute of Diabetes and Digestive and Kidney Diseases, and the National Institute of Environmental Health Sciences), we believe that they deserve credit, not criticism, for investing in novel technologies for understanding chromatin. 1. 1.[↵][3]NIH Roadmap for Medical Research, Roadmap Initiatives, Epigenomics ( ). [1]: #ref-1 [2]: pending:yes [3]: #xref-ref-1-1 View reference 1. in text