Retroviruses and primate evolution

Institute of Molecular Genetics RAS, Kurchatov Sq., 123182 Moscow, Russia.
BioEssays (Impact Factor: 4.84). 02/2000; 22(2):161-71. DOI: 10.1002/(SICI)1521-1878(200002)22:2<161::AID-BIES7>3.0.CO;2-X
Source: PubMed

ABSTRACT Human endogenous retroviruses (HERVs), probably representing footprints of ancient germ-cell retroviral infections, occupy about 1% of the human genome. HERVs can influence genome regulation through expression of retroviral genes, either via genomic rearrangements following HERV integrations or through the involvement of HERV LTRs in the regulation of gene expression. Some HERVs emerged in the genome over 30 MYr ago, while others have appeared rather recently, at about the time of hominid and ape lineages divergence. HERVs might have conferred antiviral resistance on early human ancestors, thus helping them to survive. Furthermore, newly integrated HERVs could have changed the pattern of gene expression and therefore played a significant role in the evolution and divergence of Hominoidea superfamily. Comparative analysis of HERVs, HERV LTRs, neighboring genes, and their regulatory interplay in the human and ape genomes will help us to understand the possible impact of HERVs on evolution and genome regulation in the primates. BioEssays 22:161-171, 2000.

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    ABSTRACT: Interspersed repeats occupy a significant fraction of the genetic material and represent the single major component of large eukaryotic genomes. They result from the persistent activity and gradual accumulation of transposable elements (TEs), sequences that are able to replicate in virtually all organisms and that have been successfully maintained throughout the evolution of life. Despite their selfish nature, the movement and amplification of TEs have had an enormous impact on the evolution of genes and the dynamics of genomes. Improvements to the efficiency of DNA sequencing coupled with decreases in its associated costs have fueled the sequencing of dozens of eukaryotic genomes. This has resulted in the rapid accumulation of large quantities of DNA sequences in the public databases. As such, the identification and annotation of repeats has become an integral facet of genome biology and has provoked a shift from the study of single TEs to huge populations of elements. Here we review the approaches and methods by which TEs are identified, classified and analyzed in complete eukaryotic genome sequences. We provide examples illustrating how these processes greatly facilitate genome annotation and illuminate the extent of the role of TEs in the evolution of genomes and species.