EXCLUSIVE: The biggest shake-up in a couple of decades in the casting world at big studios is occurring right now. It began a couple of months ago when veteran casting executive Nancy Foy left 2oth Century Fox and went into independent casting. Donna Isaacson, who was the most senior executive in casting at Fox and has worked there for the past 23 years, then decided to leave and also go back into independent casting. Both worked on hundreds of films at Fox, Fox 2000 and Fox Searchlight. This has all seemed to set into motion a sea change at three studios — Fox, Sony Pictures and Universal Pictures.

Tamara Hunter (who used to work with Foy and Isaacson at Fox) left and took a job at Sony in the newly created post of VP Casting — duties that were filled previously (for 15 years) by Francine Maisler. Now, Maisler was just hired at Universal after casting executive Julie Hutchinson exited that studio over a year ago. Maisler will be non-exclusive and advising Uni, working with the motion picture group on casting for projects across the entire Universal slate.

At Fox, Christian Kaplan and Brian Riley are the only ones there at the moment, though Fox is on the verge of hiring someone soon as the casting world watches the game of musical chairs.

Francine Maisler HeadshotNow, first with Maisler: She has worked on several Academy Award-winning projects including The Revenant, Birdman, The Big Short, 12 Years A Slave, Sicario, Creed and Nocturnal Animals, among others. Additionally she’s worked on Universal titles including Jason Bourne, Steve Jobs and Unbroken.

After starting her career in casting at NBC, Maisler began casting independently. She cast the breakout indie hit from Bryan Singer The Usual Suspects. She’s currently working with prominent directors Jacques Audiard and Denis Villeneuve (Blade Runner).

DonnaIsaacsonIsaacson, it should be noted, is a longtime pro. Just take a gander at some of the films she has worked on: The X-Men series, The Martian, Prometheus, Best Exotic Marigold Hotel, Planet Of The Apes, Date Night, Quills, The Crucible as well as a couple Night At The Museum installments.

Elizabeth Gabler, president of Fox 2000, praised Isaacson for her work over the years, saying, “We are deeply grateful to our longtime friend and colleague for her immense contribution to our films over the past decades. We will miss her deeply, but we are elated for her as she approaches this new phase in her amazing career and we look forward to continually working with her.”

When Deadline contacted Fox about her exit, she put together this statement: “After a remarkable 23 years at Fox, I have made the decision to venture back into independent casting, where I started my career. During my time at Fox, I have worked with many amazing filmmakers and with some of the best executives in the film business. I will miss them and all my colleagues, but I am very excited about this next chapter of my life and career.”