Edit page | Page history | Printable version

Definition

noun

A type of mutation resulting from the addition of extra nucleotides in a DNA sequence or chromosome.

Supplement

When one or more nucleotides are inserted into the genetic sequence, the reading frame is disrupted during transcription, and eventually, translation. This may result in an altered sequence of amino acids, extra amino acid in a chain, or premature termination. Hence, the newly synthesized protein could be abnormally short, abnormally long, and/or contain the wrong amino acids. It will most likely not be functional.

Insertion of a larger segment into the chromosome can also lead to mutation. It results when an unequal crossover happens during meiosis.

Compare: deletion mutation.
See also: mutation, reading-frameshift mutation.