Howard Hughes Medical Institute, Janelia Farm Research Campus, Ashburn, VA 20147, USA. amatf@janelia.hhmi.org|Howard Hughes Medical Institute, Janelia Farm Research Campus, Ashburn, VA 20147, USA. amatf@janelia.hhmi.org|Howard Hughes Medical Institute, Janelia Farm Research Campus, Ashburn, VA 20147, USA. amatf@janelia.hhmi.org