In
genetics, an
insertion (also called an
insertion mutation) is the addition of one or more
nucleotide base pairs into a
DNA sequence. This can often happen in
microsatellite regions due to the
DNA polymerase slipping. Insertions can be anywhere in size from one base pair incorrectly inserted into a DNA sequence to a section of one chromosome inserted into another. The mechanism of the smallest single base insertion mutations is believed to be through base-pair separation between the template and primer strands followed by non-neighbor base stacking, which can occur locally within the DNA polymerase active site. On a
chromosome level, an
insertion refers to the insertion of a larger sequence into a chromosome. This can happen due to unequal
crossover during
meiosis.