ST. LOUIS, MO, May 14, 2012—Arranging DNA fragments into a genome sequence that scientists can interpret is a challenge often compared to assembling a puzzle except you don’t have the box and have no idea what the picture is supposed to be. Sometimes clues from other publicly-available DNA sequences of related organisms can be used to guide the assembly process, but its usefulness depends on how closely related any two sequences are to one another. For example, a reference genome might be so distantly related from the one being assembled, it would be akin to comparing a Model-T to a contemporary hybrid car.

For researchers interested in switchgrass, a perennial grass that the U.S. Department of Energy (DOE) is investigating as a prospective biofuels feedstock, assembling the plant genome poses an even more complicated puzzle than usual because it has multiple copies of its chromosomes. The genome of a close switchgrass relative, foxtail millet (Setaria italica), is described in the...