1. Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois.
2. Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois.
3. Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois.
4. Department of Biology, School of Science and Center for Regenerative Biology and Medicine, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana.