Absence of a red blood cell phenotype in mice with hematopoietic deficiency of SEC 23 B 1 Running title : Hematopoietic SEC 23 B deficiency 2

Department of Internal Medicine, University of Michigan, Ann Arbor, MI; Department of 6 Human Genetics, University of Michigan Medical School, Ann Arbor, MI; Life Sciences 7 Institute, University of Michigan, Ann Arbor, MI; Genomic Medicine Institute, Cleveland 8 Clinic Lerner Research Institute, Cleveland, OH; Department of Pediatrics and 9 Communicable Diseases, University of Michigan, Ann Arbor, MI; Howard Hughes 10 Medical Institute, University of Michigan, Ann Arbor, MI 11