A top aide to wanna-be presidential candidate Haley Barbour has resigned after joking in an email about the Japanese tsunami tragedy. The Mississippi governor's press secretary, Dan Turner, abruptly quit following press reports of the quip. In the message, Turner referred to Otis Redding's song Sittin' on the Dock of the Bay, then noted: "Not a big hit in Japan right now." He also took a shot at former US Attorney General Janet Reno, saying it "took longer to confirm her gender" than her position. Barbour had no comment other than to accept Turner's resignation, reports Reuters. (More Haley Barbour stories.)