Independent of advances in sequencing and data mining technologies, nearly all translational and integrative genomic research relies on understanding mutations to explain biological phenomena. Despite being the most fundamental unit of genetic change, different mutations can have profoundly different effects. In the first of a three-part series on the biology underlying phenotypic diversity, we describe how insertions/deletions and repeat regions can change local mutation rates in the genomes of species ranging from bacteria to humans.
How insertions and deletions shape genome evolution
Mutations are the heart of genetic diversity and changes in DNA sequence eventually drive evolution. Can this diversity in genomes and protein structure be influenced more by one kind of mutation than others? A series of research over three years examines two conflicting ideas about the importance of insertion/deletion mutations, or “indels”, in increasing sequence diversity in species ranging from bacteria to humans.
Though there’s no clear reason why, certain regions called “genome hotspots” are known to be more prone to errors and increased mutation rates than others. Two potential explanations were examined in a Nature paper in 2008: (i) the “regional instability” hypothesis, which proposes that certain configurations of DNA bases are more unstable than others, and (ii) the “mutagenic indel” hypothesis, based on the idea that the presence of indels might increase surrounding instability to create genomic hotspots of diversity. (full text paper here)