Production has begun in Los Angeles on season four of ABC's Golden Globe-winning series "Grey's Anatomy." Entering their first year as residents, Meredith Grey, Cristina Yang, Izzie Stevens and Alex Karev now have interns of their own to mentor.

Among the new interns are George, forced to repeat his internship after failing his exams, and Lexie Grey, Meredith's half-sister.

Actress Chyler Leigh joins the cast as Lexie Grey. Born in Charlotte, North Carolina, Leigh has worked with some of the biggest talents in the business, from Aaron Spelling ("Safe Harbor," "7th Heaven") to David E. Kelley ("Girls Club," "The Practice"). Her television and film credits also include "The 80s Show," "Reunion" and "Not Another Teen Movie."

-Grey's Anatomy Pictures