Transposable Element

(also known as a transposon)

A DNA sequence that can move from one section of the genome to another, affecting chromosome shape and structure as well as gene expression.

  1. Cut-and-paste transposons move by excision from their original location and insertion into a new location, catalyzed by a transposase enzyme encoded by the transposon itself.
  2. Replicative transposons are replicated and the copy is inserted at a new location without loss of the transposon at the original location; this is also catalyzed by a transposase enzyme encoded by the transposon.
  3. Retrotransposons move via RNA transcription of the transposon followed by reverse transcription of the RNA molecule and insertion of the newly synthesized DNA.
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Posted in Science Stories

Barbara McClintock: Transposable Elements in Maize

Unexpected scientific discoveries are usually made by people who are so fascinated by the focus of their research that they probe deeply enough to find and illuminate the hitherto unknown lurking within it. They don’t begin their work hoping for acclaim or awards, but immerse themselves in it for the sheer pleasure of knowledge and discovery. (In this sense, it’s very much like free and self-directed play in small children exploring the world around them, and is powered by the same intrinsic motivation to find out why and how things work.)

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