FIG. 4.

Detection of a new ERV family in the bovine genome by OERV family-specific PCR amplification. (A) ERVs detected in porcine, bovine, and ovine genomes by degenerate PCR amplifying the pro/pol region. The β3 primers were designed according to sequence homology between pig and sheep ERVs, while the γ4 and γ9 primers were designed according to sequence homology between cattle and sheep. Pig genomic DNA was not amplified and weakly amplified by the γ4-specific (γ4-sb) and γ9-specific (γ9-sb) primers, respectively, due to nucleotide mismatches within the primer regions. The nucleotide sequences for primers were 5′-GTAGCCACTGCTCAAATTCC-3′ and 5′-GYAASACTGTCCATTGATAA-3′ for β-p5s3 (β3-specific), 5′-CTCCTCCCAAACCTGTACCA-3′ and 5′-AATACTGTCCAAGTCATCTG-3′ for γ4-sb, and 5′-AACCTGTGGCATCACTCTCN-3′ and 5′-GGAGTCCAGATGAGCTGTTN-3′ for γ9-sb. (B) PCR with OERV family-specific primers revealed a new BERV family, namely, BERV γ7. The nucleotide sequences of the family-specific primers were 5′-TTCCGTGGAGTGCTTGATAN-3′ and 5′-CTCTCCATTGATAGCGTTGN-3′ for OERV-β1, 5′-TGTTTCGGTTATTTCTCTCC-3′ and 5′-TGTCTCACAGTAATAAGAGC-3′ for OERV-β2, 5′-GATATTACTGGACTACTA-3′ and 5′-GGTACTCACAGAGATCTT-3′ for OERV-γ1A, 5′-GGCATCCTCTTGAGGTCTTN-3′ and 5′-CGAGTCCATGTCAGCTGCAN-3′ for OERV-γ2, 5′-TATAGACTGTACCAGCCGAN-3′ and 5′-GAGGTGAGTCCAGGTTAGTN-3′ for OERV-γ3, 5′-GGTATAGATGGCACGTCTTN-3′ and 5′-AGGACTGTCCACGTTAGCTN-3′ for OERV-γ5, 5′-GGCCTTCCTAATGCTATTGN-3′ and 5′-CCTTGAGGTCAATAACGGTN-3′ for OERV-γ6, 5′-TGACTTCTCTGTTCTTCCTT-3′ and 5′-TGTTCCCAGGTCCCACCACT-3′ for OERV-γ7, and 5′-CCGAAGATCAGTGGACTTGN-3′ and 5′-TCCTCATCGAAGATGGTTGN-3′ for OERV-γ8.