Zhang Pei, Wang Yu, Duan Xujie, Chen Sixu, Du Xiaoyue, Bao Anyu, Ma XinQi, Zhang Yufei, Liu Shuying
College of Veterinary Medicine, Inner Mongolia Agricultural University, Hohhot, China.
Key Laboratory of Veterinary Fundamentals and Disease Prevention and Control for Herbivorous Livestock, Hohhot, China.
Front Vet Sci. 2025 Aug 18;12:1608822. doi: 10.3389/fvets.2025.1608822. eCollection 2025.
Ovine pulmonary adenocarcinoma (OPA) is a contagious lung tumor caused by the exogenous Jaagsiekte sheep retrovirus (exJSRV). Analysing the genome of the pathogen is crucial for developing OPA prevention and control measures. Due to the absence of exogenous genomic JSRV-related information in Inner Mongolia, we aimed to establish a specific technique for exJSRV genomic amplification.
Target virions were purified using U3 hn-PCR (hemi-nested PCR) combined with density gradient centrifugation. Specific reverse transcription primers were designed using the low-identity region of the internal and external genome, combined with long fragment PCR and 3'RACE technology, and the full-length genome of exogenous JSRV from Inner Mongolia was successfully obtained.
Exogenous molecular characteristics were found in the long terminal repeat(LTR)-U3 region, gag-variable region 1/2(VR1/VR2) and env-VR3, and was 98.8% identical to the Chinese JSRV-C1, which was significantly higher than that of foreign isolates (93.05-95.84%) and enogenous Jaagsiekte sheep retrovirus (enJSRV) (88.73-92.26%). Phylogenetic analysis showed that NMJS12 and exogenous JSRV-C1 were located in the same evolutionary clade. Accordingly, the whole genome eukaryotic expression plasmid was successfully constructed and viral particle packaging was achieved in 293T cells.
Altogether, this study represents the first elucidation of the complete genome of exogenous JSRV in Inner Mongolia, China and provides a critical material foundation for antiviral target screening and research on OPA pathogenesis.
绵羊肺腺瘤（OPA）是由外源性绵羊肺腺瘤逆转录病毒（exJSRV）引起的一种传染性肺肿瘤。分析病原体的基因组对于制定OPA的预防和控制措施至关重要。由于内蒙古缺乏外源性基因组JSRV相关信息，我们旨在建立一种exJSRV基因组扩增的特异性技术。
使用U3半巢式PCR（hn-PCR）结合密度梯度离心法纯化目标病毒粒子。利用基因组内部和外部的低同源区域设计特异性逆转录引物，结合长片段PCR和3'RACE技术，成功获得了内蒙古外源性JSRV的全长基因组。
在外源分子特征方面，在长末端重复序列（LTR）-U3区域、gag可变区1/2（VR1/VR2）和env-VR3中发现，与中国JSRV-C1的同源性为98.8%，显著高于国外分离株（93.05-95.84%）和内源性绵羊肺腺瘤逆转录病毒（enJSRV）（88.73-92.26%）。系统发育分析表明，NMJS12和外源性JSRV-C1位于同一进化分支。据此，成功构建了全基因组真核表达质粒，并在293T细胞中实现了病毒颗粒包装。
总之，本研究首次阐明了中国内蒙古外源性JSRV的完整基因组，为抗病毒靶点筛选和OPA发病机制研究提供了关键的物质基础。
