Yamagami Shunsuke, Sato Jumpei, Motai Yoshinosuke, Maekawa Naoya, Okagawa Tomohiro, Konnai Satoru, Ohashi Kazuhiko, Murata Shiro
Laboratory of Infectious Diseases, Department of Disease Control, Faculty of Veterinary Medicine, Hokkaido University, Hokkaido, Japan.
Department of Advanced Pharmaceutics, Faculty of Veterinary Medicine, Hokkaido University, Hokkaido, Japan.
J Vet Med Sci. 2025 May 15;87(5):517-531. doi: 10.1292/jvms.25-0011. Epub 2025 Apr 3.
Marek's disease virus (MDV) is an oncogenic herpesvirus that causes malignant lymphomas in chickens (Marek's disease, MD). Although MD is currently well controlled by vaccination, field strains of MDV tend to increase in virulence, and sporadic outbreaks have been reported worldwide, including in Japan. Previously, we determined the whole-genome sequence of a Japanese MDV strain, Kgs-c1, isolated in 2014, and analyzed its genetic characteristics. However, to date, Kgs-c1 is the only MDV strain that has been subjected to whole-genome sequencing, leaving the possibility that the key genetic features of the Japanese strains remain undiscovered. Therefore, we conducted whole-genome sequencing of two MDV strains, Kgs-c2 and Sg-c1, isolated in 2016 and 2019, respectively, and analyzed their genetic characteristics. Consistent with our previous findings, the genomic sequences of the Japanese strains were classified into the Eurasian cluster, suggesting that the Japanese strains are genetically closer to the European and Chinese strains than they are to the US strains. In contrast, the Japanese strains exhibited genetic features different from those of pathogenic European and Chinese strains. Furthermore, polymorphisms in the meq and infected cell protein 4 (ICP4) genes, which are candidates involved in the enhanced virulence of MDV, were observed among the newly isolated strains and Kgs-c1. Thus, three MDV strains isolated in Japan had different genetic features from those in other countries. These findings emphasize the necessity of periodic monitoring of MDV field strains in order to determine shifts in their characteristics and effectively control MD.
马立克氏病病毒（MDV）是一种致癌性疱疹病毒，可导致鸡发生恶性淋巴瘤（马立克氏病，MD）。尽管目前通过疫苗接种能很好地控制MD，但MDV的野毒株毒力往往会增强，并且在全球范围内都有散发病例的报道，包括在日本。此前，我们测定了2014年分离的一株日本MDV毒株Kgs-c1的全基因组序列，并分析了其遗传特征。然而，迄今为止，Kgs-c1是唯一一株进行了全基因组测序的MDV毒株，这使得日本毒株的关键遗传特征仍有可能未被发现。因此，我们分别对2016年和2019年分离的两株MDV毒株Kgs-c2和Sg-c1进行了全基因组测序，并分析了它们的遗传特征。与我们之前的研究结果一致，日本毒株的基因组序列被归类为欧亚集群，这表明日本毒株在遗传上与欧洲和中国毒株的关系比与美国毒株的关系更密切。相比之下，日本毒株表现出与致病性欧洲和中国毒株不同的遗传特征。此外，在新分离的毒株和Kgs-c1中观察到了meq和感染细胞蛋白4（ICP4）基因的多态性，这些基因是与MDV毒力增强有关的候选基因。因此，在日本分离的三株MDV毒株具有与其他国家毒株不同的遗传特征。这些发现强调了定期监测MDV野毒株的必要性，以便确定其特征的变化并有效控制MD。
