When Mary Cooper (Laurie Metcalf) introduces herself as "Sheldon's mother" to Dr. Eric Gablehauser (Mark Harelik), Sheldon's boss, he says that's impossible and that she must've had Sheldon when she was a teenager. Laurie Metcalf is 17 years older than Jim Parsons.
On Dr. Gablehauser's shelf are two photographs. One is of him shaking hands with Bill Clinton. The other shows him talking to President George Bush.
Johnny Galecki and Sara Gilbert previously costarred together in Roseanne (1988), which also featured Laurie Metcalf - a guest star in this episode.
When rehearsing what he is going to say to Dr. Gablehauser, Sheldon ends with "Mahalo." This is a Hawaiian word which loosely translates as "Thank you" but is also used to express admiration, gratitude or respect.
Title Reference: Sheldon produces glow-in-the-dark fish in this episode.