Novel Endogenous Retrovirus in the Slow Loris

Abstract

Endogenous retroviruses (ERVs) are the result of an exogenous infectious retrovirus becoming integrated within the host genome through infection of germline cells. The majority of ERV research has been conducted on humans and other great apes and research of them within other primates can provide unique insights. Screening the genome of two endangered slow lorises Nycticebus bengalensis and N. coucang with a previously identified LTR, a novel ERV was identified within their genomes with varying levels of completeness and numerous solo LTRs. Phylogenetic analysis of the genes of this ERV indicates that it is a betaretrovirus most closely related to HERV-K. Despite being closely related to HERV-K, the ERV does not appear to be within humans and is only found in Asian lorises and absent in all other primates. Due to the staggering similarity of viral insertions of this ERV between the two species of slow lorises, indicates that the current N. coucang genome may actually be a hybrid of the two species or a N. bengalensis from a different population as the reference genome. This study highlights that studying ERVs in more distant primates provides information about the genomes and evolution of these species as well as viral evolution.