Ryan Reynolds and Jason Bateman have signed on to star in Universal’s body-switching comedy “The Change-Up.”Story centers on a responsible family man (Bateman) who switches bodies with his best friend, a lazy man-child (Reynolds). Neal Moritz has come aboard to produce alongside David Dobkin, who has been overseeing development of the project and will also direct. Screenplay was written by Jon Lucas and Scott Moore (“The Hangover”). Now that Universal has found its two leads, “Change-Up” is ramping up for a tentative September start date. Bateman, who is onscreen in “Up in the Air,” has become something of a go-to thesp for Universal and is said to have doubled his quote for the “Change-Up” role. His previous projects with the studio include “Smokin’ Aces,” “The Kingdom,” “State of Play” and “Couples Retreat.” He also has the U comedy “Paul” coming out this year and is attached to “The Remarkable Fellows,” which is in development at Universal. Bateman will next be seen opposite Jennifer Aniston in Disney’s “The Switch,” due out Aug. 20. Reynolds has seen his star rise, having starred in two box office hits last year: “The Proposal” and “X-Men Origins: Wolverine.” He is attached to reprise his role as Deadpool in an X-Men spinoff for Fox.Bateman and Reynolds are repped by CAA. Bateman is additionally managed by 3 Arts.