1. Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.
2. Program in Epigenetics, University of Pennsylvania, Philadelphia, PA 19104, USA.
3. Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA.
4. School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA.
5. Department of Biology, New York University, New York, NY 10003, USA.
6. Department of Entomology, University of California, Riverside, CA 92521, USA.
7. Department of Biological Sciences, Vanderbilt University, Nashville, TN 37232, USA.
8. Department of Molecular Pharmacology and Biochemistry, New York University School of Medicine, New York, NY 10016, USA.
9. Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.