title: Phylogeny, recombination and expression of porcine endogenous retrovirus gamma2 nucleotide sequences.
abstract: Endogenous retroviral sequences in the pig genome represent a potential infectious risk in xenotransplantation. Porcine endogenous retrovirus (PERV) gamma sequences described to date have been classified into several families. The known infectious, human-tropic PERVs have been assigned to the PERV gamma1 subfamilies A, B and C. High copy numbers and full-length clones have also been observed for an additional family, designated PERV gamma2. The aim of this study was to examine the PERV gamma2 family by analysis of retroviral pro/pol gene sequences. The proviral load was observed to be similar among various pig breeds. Although clones harbouring an open reading frame in the examined region were found, analysis of published large PERV gamma2 clones revealed multiple deleterious mutations in each of the retroviral genes. Various recombination events between gamma2 genomes were revealed. In contrast to PERV gamma1, phylogenetic analyses did not distinguish defined subfamilies, but indicated the independent evolution of the proviruses after a single event of retroviral amplification. Expression analysis showed large PERV gamma2 transcripts and variable transcription in several tissues. Analysis of the two published gamma2 env gene sequences observed the partial lack of the receptor-binding domain. Overall, this study indicated the low infectious potential for PERV gamma2.
authors.affiliation: ApoGene Biotechnologie, D-86567 Hilgertshausen, Germany.|Institut für Tierzucht und Genetik, Veterinärmedizinische Universität Wien, A-1210 Wien, Austria.
authors.forename: Nikolai
authors.initials: N
authors.lastname: Klymiuk
authors.affiliation: Institut für Tierzucht und Genetik, Veterinärmedizinische Universität Wien, A-1210 Wien, Austria.
authors.forename: Mathias
authors.initials: M
authors.lastname: Müller
authors.affiliation: ApoGene Biotechnologie, D-86567 Hilgertshausen, Germany.
authors.forename: Gottfried
authors.initials: G
authors.lastname: Brem
authors.affiliation: Lehrstuhl für Molekulare Tierzucht und Biotechnologie, Ludwig-Maximilians-Universität München, D-85764 Oberschleißheim, Germany.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Aigner
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D020077:Endogenous Retroviruses / Q000737:chemistry / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D005260:Female; D015686:Gene Products, env / Q000737:chemistry; D015684:Gene Products, pol / Q000737:chemistry; D008969:Molecular Sequence Data; D009928:Organ Specificity; D010802:Phylogeny; D020815:Polyproteins / Q000737:chemistry; D011995:Recombination, Genetic; D017422:Sequence Analysis, DNA; D013552:Swine / Q000821:virology*; D013556:Swine, Miniature / Q000821:virology
chemical_list: D015686:Gene Products, env; D015684:Gene Products, pol; D020815:Polyproteins