Endogenization of a prosimian retrovirus during lemur evolution

Studies of viruses that coevolved with lemurs provide an opportunity to understand the basal traits of primate viruses and provide an evolutionary context for host-virus interactions. Germline integration of endogenous retroviruses (ERVs) are fossil evidence of past infections. Hence, characterization of novel ERVs provides insight into the ancient precursors of extant viruses and the evolutionary history of their hosts. Here, we report the discovery of a novel endogenous retrovirus present in the genome of a lemur, Coquerel\u27s sifaka

Isolation and Genomic Analysis of Cluster O Mycobacteriophage Vorrps

Mycobacteriophage Vorrps was isolated in 2014 from soil on the Washington University campus. The phage was isolated and purified by repeatedly infecting host Mycobacterium smegmatis. Vorrps produces small, circular, clear plaques approximately 1 mm in diameter, indicating that it is a lytic phage. Electron microscopy reveals that Vorrps has an unusual prolate head and a long tail characteristic of cluster O mycobacteriophage. Vorrps is very similar to the five analyzed O cluster phages Corndog, Catdawg, YungJamal, Firecracker and Dylan, as well as cluster O phage Mori, another phage isolated and analyzed by Washington University students this year. Vorrps and Mori are the first cluster O phage to be isolated at Washington University. Vorrps has a genome of 71,721 base pairs long. 125 genes have been annotated, 68 of which run in the negative direction, the remaining 58 running in the positive direction. A majority of the suggested genes have no known function, much like other O cluster phage. Currently each team member is investigating one of the following interesting features of the Vorrps genome: gene overlaps, tape measure gene chaperone frameshift, cluster O phage common repeat sequences, and the functionality of the prolate head

Endogenization of a Prosimian Retrovirus during Lemur Evolution

Studies of viruses that coevolved with lemurs provide an opportunity to understand the basal traits of primate viruses and provide an evolutionary context for host-virus interactions. Germline integration of endogenous retroviruses (ERVs) are fossil evidence of past infections. Hence, characterization of novel ERVs provides insight into the ancient precursors of extant viruses and the evolutionary history of their hosts. Here, we report the discovery of a novel endogenous retrovirus present in the genome of a lemur, Coquerel’s sifaka (Propithecus coquereli). Using next-generation sequencing, we identified and characterized the complete genome sequence of a retrovirus, named prosimian retrovirus 1 (PSRV1). Phylogenetic analyses indicate that PSRV1 is a gamma-type betaretrovirus basal to the other primate betaretroviruses and most closely related to simian retroviruses. Molecular clock analysis of PSRV1 long terminal repeat (LTR) sequences estimated the time of endogenization within 4.56 MYA (±2.4 MYA), placing it after the divergence of Propithecus species. These results indicate that PSRV1 is an important milestone of lemur evolution during the radiation of the Propithecus genus. These findings may have implications for both human and animal health in that the acquisition of a gamma-type env gene within an endogenized betaretrovirus could facilitate a cross-species jump between vertebrate class hosts