The new ABC drama “Mistresses” is now in pre-production and Mary Jo Slater is casting recurring, guest starring, and day player roles. The series was created by Gossip Girl writer K.J. Steinberg, based on the hit BBC series of the same name. ABC picked up “Mistresses” as a 12 episode midseason order. In addition to acting roles, extras of all ages and types will be cast throughout the season. Shooting begins on August 7, 2012 in Los Angeles. The show follows four friends as they try to deal with complex relationships and toward a sense of order and enlightenment in their lives.