Question: who from roseanne is on big bang theory

title: Johnny Galecki
text: Galecki plays Leonard Hofstadter in the CBS sitcom The Big Bang Theory , which debuted September 24 , 2007 . He was originally asked to play the role of Sheldon Cooper , but he said he was better suited for the role of Leonard Hofstadter , and Sheldon 's role was eventually given to Jim Parsons . During his role as David Healy on Roseanne , Sara Gilbert played his longtime girlfriend and later wife , Darlene Conner . She has appeared as Leslie Winkle , a colleague in the Big Bang Theory . Laurie Metcalf , who portrayed Roseanne 's sister Jackie Harris , has appeared as Mary Cooper , mother of Leonard 's roommate , Sheldon . Galecki is a cellist , a talent which has been used on the show . As of August 2013 , Galecki and his Big Bang costars Kaley Cuoco and Jim Parsons each earned US $325,000 per episode . As of August 2014 , the three costars will earn US $1 million per episode . 

Answer: answer: Johnny Galecki plays Leonard Hofstadter in the CBS sitcom The Big Bang Theory. During his role as David Healy on Roseanne, Sara Gilbert played his longtime girlfriend. She has appeared as Leslie Winkle, a colleague in the Big Bang Theory. Laurie Metcalf, who portrayed Roseanne's sister Jackie Harris, has appeared as Mary Cooper, mother of Leonard's roommate, Sheldon.