Robinson A J, Barns G, Fraser K, Carpenter E, Mercer A A
Virology. 1987 Mar;157(1):13-23. doi: 10.1016/0042-6822(87)90308-4.
The genomes of several orf virus strains were analyzed with the restriction endonucleases EcoRI, HindIII, BamHI, and KpnI, and cleavage site maps were deduced. In general, the right half of the genome showed conservation of restriction sites compared with the left half. Variations in size of up to 0.5 kbp were found within an inverted terminal repetition, and a 1-kbp deletion was detected in some strains in a subterminal fragment at the left end. A region of approximately 20 kbp, some 12 kbp in from the left end, showed the greatest cleavage site variability although there was no evidence of large deletions in this region. A 1.55-kbp cloned DNA fragment from the internal variable region of NZ2 failed to hybridize to the DNA from three other strains. A fragment in the variable region of strain NZ7 was cloned and compared by hybridization and restriction endonuclease analysis with cloned NZ2 fragments from the same region. The region of nonhomology extended for at least 2.75 kbp. It is suggested that this internal variable region may provide sites for the insertion of foreign genes.
用限制性内切酶EcoRI、HindIII、BamHI和KpnI分析了几种orf病毒株的基因组，并推导了切割位点图谱。总体而言，与基因组左半部分相比，右半部分的限制性位点表现出保守性。在反向末端重复序列中发现大小变化高达0.5 kbp，并且在左端亚末端片段的一些毒株中检测到1 kbp的缺失。尽管该区域没有大的缺失证据，但从左端起约12 kbp处的一个约20 kbp的区域显示出最大的切割位点变异性。来自NZ2内部可变区的一个1.55 kbp克隆DNA片段未能与其他三种毒株的DNA杂交。克隆了毒株NZ7可变区的一个片段，并通过杂交和限制性内切酶分析与来自同一区域的克隆NZ2片段进行比较。非同源区域至少延伸2.75 kbp。有人提出，这个内部可变区可能为外源基因的插入提供位点。
