Endogenous retrovirus-mediated genomic variations in chimpanzees.

Transposable elements (TEs) have played a significant role in the evolution of host genome by triggering genomic rearrangements. TEs have been studied in various research fields, ranging from population genomics to personalized medicines. Human-specific TEs and TEs existing in the human genome have been well studied. Unlike them, non-human primate-specific TEs remain shrouded in mystery. However, the study of TE-mediated genomic or genetic variations through comparative genomics is essential to understand mechanisms which TEs utilize to modify species-specific genome architecture and to cause species-specific diseases, Therefore, we have studied chimpanzee-specific TEs as well as human-specific TEs. At first, we identified human-specific HERV-K integrated into the human genome after the divergence of human and chimpanzee. Then, for a comparative study of HERV-Ks and non-human ERVs, we extracted chimpanzee-specific endogenous retroviruses (PtERVs) from the chimpanzee genome. We identified 256 chimpanzee-specific PtERVs and characterized them, focusing on their estimated evolutionary age, polymorphism level in chimpanzee populations, and potential impact on the difference between the human and chimpanzee genomes.