Clusters of Nucleotide Substitutions and Insertion/Deletion Mutations Are Associated with Repeat Sequences
Figure 2
Indels in prokaryotes are only heterogenote for a short period of time between DNA replication and cell division.
Cells have up to four copies of their genome during rapid growth. This raises the possibility that indels could be mutagenic during their attempted repair using the non-indel-containing chromosome copy. Following cell division, one of the daughter cells will possess an indel-containing chromosome, while the other daughter cell will not. The indel lineage will thereafter be homogenote for the indel. According to the previously proposed mutagenic-when-heterozygous hypothesis, the indel will not be mutagenic as it no longer exists as a heterogenote and nucleotide substitutions will not accumulate around them.