Recombination hotspot

With the English term hotspot ( German: " particularly active site " ) is referred to in ancient DNA research, a site can be observed on the most frequently post-mortem changes in the DNA strand.

After the death of a living being immediately autolysis (decomposition) of molecular cell components, including the genetic material, the DNA begins. The decomposition processes do not always lead to the complete separation of the DNA strands, but can also cause structural changes to individual bases or base pairs that lead to reproductive defects in the technical reproduction (polymerase chain reaction, PCR), and thus indirectly to reading errors in sequencing. These structural changes are considered damage ( German: " damage " ) referred. You can frequently, and occur in the vicinity of positions in the DNA molecule, which were also preferred Rekombinationsfehler ( point mutations ) in the living organism occur ( mutational hotspots ). Such, possibly labile structural reasons, areas are called hotspots.

At these hotspots a distinction between in vivo mutation and post-mortem change using conventional processing and sequencing method is not completely possible. The treatment of the samples prior to PCR with uracil -N- glycosylase leads to the destruction of changed molecular radicals. In addition, statistical methods are used to " clean up " ancient DNA sequences of postmortem artifacts to.