The U.S. Justice Department is suing an Oklahoma university, charging that school officials discriminated against a professor who changed gender during her time working there. Rachel Tudor was hired as a tenure-track assistant professor in the English department at Southeastern Oklahoma State University in 2004, after applying as a man with a traditionally male name, according to the lawsuit filed Monday. Then in 2007, Tudor told school officials that he would become a woman during that academic year, took the name Rachel, and began wearing women’s clothes and a traditionally female hairstyle. U.S. Attorney General Eric H. Holder Jr. announced in December that federal prohibitions against sex discrimination include protections based on gender identity.