Alu-elements comprise a large part of the human genome and some insertions have been shown to cause diseases. Here, we illuminate the protective role of an Alu-element in the 3'UTR of the human Factor 9 gene and its ability to ameliorate a poly(A) site mutation in a hemophilia B patient, preventing him from developing a severe disease. Using a minigene, we examined the disease-causing mutation and the modifying effect of the transposon in cellulo. Further, we simulated evolutionary scenarios regarding alternative polyadenylation before and after Alu insertion. A sequence analysis revealed that Old World monkeys displayed a highly conserved polyadenylation sites in this Alu-element, whereas New World monkeys lacked this motif, indicating a selective pressure. We conclude that this transposon has inserted shortly before the separation of Old and New World monkeys and thus also serves as a molecular landmark in primate evolution.
Copyright: © 2024 Kopp et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.