19. “Hot-spots” hypermutability is due to the presence of some repeated nucleotide sequences – the “microsatellites” of two or three nucleotides, as ATATATAT – which can disturb the activity of the enzymes of replication (the DNA polymerases) by inducing them to slippage, and by provoking frame-shift mutations. For instance, mutational “hot-spots” have been observed in genes involved in the production of cellular factors interacting with highly unpredictable environment (e.g., in Neisseria and Influenzae’s pathogenic bacteria’s genome amongst genes coding for surface proteins, which are very important in the interaction with host defenses; in antigens of the immune system of the host, which directly interact with pathogens). See Moxon et al. 1994, 2006.


 [ return to text ]