Stars Katey Sagal and Kaley Cuoco reunite to star in new Big Bang Theory series

Katey Sagal, left, and Kaley Cuoco, centre in 8 Simple Rules

Katey Sagal, left, and Kaley Cuoco, centre in 8 Simple Rules

Leonard and Penny on The Big Bang Theory

Katey Sagal, left, and Kaley Cuoco, centre in 8 Simple Rules

Kaley Cuoco, pictured, and Katey Sagal are to reunite on The Big Bang Theory

thumbnail: Katey Sagal, left, and Kaley Cuoco, centre in 8 Simple Rules
thumbnail: Katey Sagal, left, and Kaley Cuoco, centre in 8 Simple Rules
thumbnail: Leonard and Penny on The Big Bang Theory
thumbnail: Katey Sagal, left, and Kaley Cuoco, centre in 8 Simple Rules
thumbnail: Kaley Cuoco, pictured, and Katey Sagal are to reunite on The Big Bang Theory

Katey Sagal and Kaley Cuoco will be reuniting to play a TV mother and daughter on The Big Bang Theory, 11 years after they last starred together.

Sons Of Anarchy star Sagal has been been cast as Susan, the mother of Cuoco's character Penny, in the upcoming series 10 of the hit US sitcom, it was revealed by executive producer Steve Molaro at the show's Comic-Con panel on Friday.

It is a reunion a long-time in the making as the pair last starred together as Cate and Bridget Hennessy on comedy 8 Simple Rules, which ran from 2002 to 2005.

Cuoco shared her delight at the news on Instagram with a picture of the pair, writing, "Yes yes yes yes !!! Once my tv mom, always my tv mom. Love you @kateylous !!!!! #fullcircle"

Katey Sagal, left, and Kaley Cuoco, centre in 8 Simple Rules

30 Rock's Jack McBrayer has been cast as Penny's brother Randall and Molaro confirmed both will appear in the season premiere.

Penny's family have been mentioned frequently throughout the show, but only her father, played by Keith Carradine, has ever been seen.

Cuoco's character Penny married boyfriend Leonard Hofstadter, played by Johnny Galecki, at the beginning of series nine and the final episode saw them hold a second wedding ceremony without Penny's family present.

Leonard and Penny on The Big Bang Theory