Kim Jung-Mi, Kim Jung-Ae, Park Jin-Ah, Park Seung-Moon, Cha Byeong-Jin, Yang Moon-Sik, Kim Dae-Hyuk
Institute of Molecular Biology and Genetics, Research Center of Bioactive Materials, Chonbuk National University, Chonbuk 561-756, Republic of Korea.
J Microbiol. 2009 Aug;47(4):441-7. doi: 10.1007/s12275-009-0206-7. Epub 2009 Sep 9.
Genetic diversity of the chrysovirus within the four fungal strains was analyzed by comparing the full-length sequences of cloned chrysoviral genes encoding the RNA-dependent RNA polymerase (RdRp) and capsid protein (CP). Because the morphological characteristics of four chrysovirus-infected Cryphonectria spp. strains were different, strain identification was conducted via sequence comparison of the internal transcribed spacers (ITSs) of the fungal rRNA gene. Phylogenic analysis of the ITS regions revealed that the four strains were closely clustered with the reference strain of Cryphonectria nitschkei, while they were more distantly related to other common Cryphonectria species, indicating that they were likely C. nitschkei. Sequence comparison among chrysoviruses from Korean C. nitschkei strains revealed that similarities of the RdRp and CP genes ranged from 98% to 100% and from 95% to 100%, respectively, at the protein level. Their corresponding nucleotide sequences showed 97% to 100% and 84% to 100% identities, respectively. Compared to RdRp, the CP gene had more divergence, suggesting the presence of genes possessing different evolutionary rates within the chrysovirus genome. Sequence comparisons with other known chrysoviruses showed that the four Korean chrysoviruses were clustered together at the next lineage level. Discovering why two strains (bsl31 and bsl32) containing identical ITS sequences and chrysoviruses display different phenotypes should prove interesting.
通过比较克隆的编码RNA依赖的RNA聚合酶（RdRp）和衣壳蛋白（CP）的金黄病毒基因的全长序列，分析了四种真菌菌株内金黄病毒的遗传多样性。由于四种感染金黄病毒的隐孢壳属菌株的形态特征不同，通过真菌rRNA基因的内部转录间隔区（ITS）的序列比较进行菌株鉴定。ITS区域的系统发育分析表明，这四种菌株与尼氏隐孢壳参考菌株紧密聚类，而它们与其他常见的隐孢壳属物种的亲缘关系较远，表明它们可能是尼氏隐孢壳。来自韩国尼氏隐孢壳菌株的金黄病毒之间的序列比较显示，RdRp和CP基因在蛋白质水平上的相似性分别为98%至100%和95%至100%。它们相应的核苷酸序列分别显示出97%至100%和84%至100%的同一性。与RdRp相比，CP基因有更多的差异，表明在金黄病毒基因组内存在具有不同进化速率的基因。与其他已知金黄病毒的序列比较表明，这四种韩国金黄病毒在下一个谱系水平上聚类在一起。探究为什么两个含有相同ITS序列和金黄病毒的菌株（bsl31和bsl32）表现出不同的表型应该会很有趣。
