A novel jumbo bacteriophage (myovirus) is described. The lytic phage of Tenacibaculum maritimum, which is the etiological agent of tenacibaculosis in a variety of farmed marine fish worldwide, was plaque-isolated from seawater around a fish aquaculture field in Japan. The phage had an isometric head 110-120 nm in diameter, from which several 50- to 100-nm-long flexible fiber-like appendages emanate, and a 150-nm-long rigid contractile tail. The full genomes of the two representative phages (PTm1 and PTm5) were 224,680 and 226,876 bp long, respectively, both with 29.7% GC content, and the number of predicted open reading frames (ORFs) was 308 and 306, respectively. The average nucleotide sequence identity between PTm1 and PTm5 was 99.95%, indicating they are quite similar to each other. A genetic relationship was found in 15.0-16.6% of the predicted ORFs among the T. maritimum phages PTm1 and PTm5, the Tenacibaculum spp. phage pT24, and the Sphingomonas paucimobilis phage PAU. Phylogenetic analysis based on the terminase large subunit genes revealed that these four phages (PTm1, PTm5, pT24 and PAU) are more closely related than the other 10 jumbo myoviruses that have similar genome sizes. Transmission electron microscopy observations suggest that the head fibers of the T. maritimum phage function as tentacles to search and recognize the host cell surface to facilitate infection.

中文翻译：

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一种新颖的巨型海藻Tenacibaculum marilyticum噬菌体，带有类似头纤维的附属物。

描述了一种新型的巨型噬菌体（肌病毒）。在日本鱼类水产养殖场周围的海水中，斑块分离出了海生的Tenacibaculum的裂解噬菌体，Tenacibaculum的裂解噬菌体是全世界各种养殖海水鱼的病原体。噬菌体具有等轴测头，直径为110-120 nm，从该等轴测头发出多个50至100 nm长的柔性纤维状附肢，以及一个150 nm长的刚性收缩尾巴。两个代表性噬菌体（PTm1和PTm5）的完整基因组分别长224,680和226,876 bp，均具有29.7％的GC含量，预测的开放阅读框（ORF）数分别为308和306。PTm1和PTm5之间的平均核苷酸序列同一性为99.95％，表明它们彼此非常相似。在15.0-16中发现了遗传关系。海上T.噬菌体PTm1和PTm5，Tenacibaculum spp中预测的ORF的6％。噬菌体pT24，和鞘氨醇单胞菌噬菌体PAU。基于末端酶大亚基基因的系统发育分析表明，这四个噬菌体（PTm1，PTm5，pT24和PAU）比其他10个具有相似基因组大小的巨型肌病毒更紧密相关。透射电子显微镜的观察结果表明，海藻T.噬菌体的头部纤维充当触角，以搜寻和识别宿主细胞表面以促进感染。与其他10个基因组大小相似的巨型肌病毒相比，pT24和PAU具有更紧密的联系。透射电子显微镜的观察结果表明，海藻T.噬菌体的头部纤维充当触角，以搜寻和识别宿主细胞表面以促进感染。与其他10个基因组大小相似的巨型肌病毒相比，pT24和PAU具有更紧密的联系。透射电子显微镜的观察结果表明，海藻T.噬菌体的头部纤维充当触角，以搜寻和识别宿主细胞表面以促进感染。