1 Department of Anatomy & Cell Biology, University of Iowa, Carver College of Medicine, Iowa City, IA 52242, USA. Electronic address: ziying-yan@uiowa.edu.
2 Department of Anatomy & Cell Biology, University of Iowa, Carver College of Medicine, Iowa City, IA 52242, USA.
3 Department of Anatomy & Cell Biology, University of Iowa, Carver College of Medicine, Iowa City, IA 52242, USA. Electronic address: john-engelhardt@uiowa.edu.