Department of Mathematics, Iowa State University, Ames, IA 50011, USA.|Department of Biology, Boston College, Chestnut Hill, MA 02467, USA.|Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, NC 29425, USA.|Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, NC 29425, USA.|Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA 50011, USA.|Department of Genetics, Development and Cell Biology, Iowa State University, Ames, IA 50011, USA.|Ken and Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.|Ken and Ruth Davee Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA.|Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, NC 29425, USA.|Department of Computer Science, College of Charleston, Charleston, SC 29424, USA.