The env protein deduced from env gene encodes the hydrophilic surface protein ( su ) and the hydrophobic transmembrane domain ( tm ) that determine the specific interaction between virus particles and cell surface receptors during retroviral entry . the su of retroviruses is a highly variable genetic element , containing receptor binding sites and major antigenic determinants . exjsrv - specific dna probes were derived . by using these dna probes in tissue hybridization . we successfully identified jsrv mrna expression and proviruses dna in sheep lung tissues infected with jsrv and control group has no postive signals , validating the use of exogenous virus - specific dna probes in the analysis of oncogenic proviral integration sites and identification of integrated exogenous proviral sequences 用地高辛随机引物法标记exjsrv特异的env片段，制备探针，原位杂交检测spa肺组织中的rna及前病毒dna ，结果表明spa患羊肺组织内有jsrvenv基因mrna的表达，同时也检测到了前病毒dna ，而相应的阴性对照却无阳性信号，证实外源性病毒特异的dna探针在致瘤性前病毒的整合位点和整合的外源性前病毒的检测中具有可信度。
2.
The proviral genome cdna clone of snv strain was digested , and the fragments was cloned into the puc18 vector , sequenced , finally we got the sequence of snv genome . the two pairs of primers were designed and synthesized according to the snv strain env sequence . the env genes of the rev isolates isolated from china were amplified by polymerase chain reaction ( pcr ) 根据网状内皮增生症病毒snv株env基因的序列，设计并且合成了两对引物，利用该引物，以中国地方分离株sd9901 、 ha9901前病毒基因组cdna为模板，通过pcr技术，成功的从国内分离得两株rev毒株中扩增出env基因，并将之克隆进pucm - t载体中测序。
