The Study Of Endogenous Retroviruses In Rhinopithecus Roxellanae,Rhinopithecus Bieti And Trachypithecus Francoisi

Endogenous retroviruses(ERVs)are remnants of former exogenous retroviruses that had previously invaded the germ line of the host that can be vertically transmitted across generations.ERV documented past retroviral infections and thus provide important molecular evidence for studying the evolution of retroviruses and their hosts.So far,ERVs have been reported in every vertebrate class examined and are associated with leukemias,immunodeficiencies and neurological.However,little is known about ERVs in colobine genomes.Therefore,we used a TBLASTN program to search the ERV sequences of Rhinopithecus roxellanae,Rhinopithecus bieti and Trachypithecus francoisi genome.We retrieved all complete accession sequences from the homology search and then used the program,RetroTector,to check and identify the ERV sequences.We analyzed the classification of ERV sequences with full-length and analyzed the homologous sequences and the ERV-neighboring genes in two snub-nosed monkeys.Finally,we discussed the potential impact of ERVs on diseases.The main results are as follows:We identified a total of 945 ERV sequences.We found 284 ERV sequences and the proportion of full-length sequences of all ERVs was 30%in R.roxellana.263 ERV sequences were found in R.bieti and the proportion of full-length sequences was 21%.398 ERV sequences were found in T.francoisi and the proportion of full-length sequences was 40%.Phylogenetic analysis of identified full-length ERVs showed that ERVs were described as class ? and class ?.Most of ERV sequences in snub-nosed monkeys were related to gamma-retroviruses and beta-retroviruses while most of ERV sequences in Francois' langur were related to gamma-retroviruses and lenti-retroviruses.The truncation pattern distribution in the three species was virtually identical.The fewest truncation patterns in the three species were gag truncations and pol truncations while the majority of truncation patterns were long terminal repeats truncations,PBS truncations and PPT truncations.By comparing ERV sequences in snub-nosed monkeys we found 13 pairs of homologous ERV sequences.We used one as query sequences and found similar ERV sequences in 6 primate species.And their phylogenetic tree showed that the evolutionary history of ERVs tends to broadly follow the evolutionary history of their hosts.We also examined ERV-like sequences and found 48 such genes in R.roxellana and 63 in R.bieti.Some of those genes are associated with diseases,suggesting that ERVs might have involved the abnormal expression of certain genes that have contributed to deleterious consequences for the host.Our results indicate that ERV sequences are widely distributed in snub-nosed monkeys and Francois' langur,and their phylogenetic history can mirror that of their hosts over long evolutionary time scales.In addition,ERV sequences appear to have an important influence on the evolution of host pathology.And our results help us to understand the elassifieation,diversity and evolution of ERV sequences in colobinae.