Tsai M F, Lo C F, van Hulten M C, Tzeng H F, Chou C M, Huang C J, Wang C H, Lin J Y, Vlak J M, Kou G H
Department of Zoology, Institute of Biochemistry, Taipei, Taiwan.
Virology. 2000 Nov 10;277(1):92-9. doi: 10.1006/viro.2000.0596.
The causative agent of white spot syndrome (WSS) is a large double-stranded DNA virus, WSSV, which is probably a representative of a new genus, provisionally called Whispovirus. From previously constructed WSSV genomic libraries of a Taiwan WSSV isolate, clones with open reading frames (ORFs) that encode proteins with significant homology to the class I ribonucleotide reductase large (RR1) and small (RR2) subunits were identified. WSSV rr1 and rr2 potentially encode 848 and 413 amino acids, respectively. RNA was isolated from WSSV-infected shrimp at different times after infection and Northern blot analysis with rr1- and rr2-specific riboprobes found major transcripts of 2.8 and 1.4 kb, respectively. 5' RACE showed that the major rr1 transcript started at a position of -84 (C) relative to the ATG translational start, while transcription of the rr2 gene started at nucleotide residue -68 (T). A consensus motif containing the transcriptional start sites for rr1 and rr2 was observed (TCAc/tTC). Northern blotting and RT-PCR showed that the transcription of rr1 and rr2 started 4-6 h after infection and continued for at least 60 h. The rr1 and rr2 genes thus appear to be WSSV "early genes."
白斑综合征（WSS）的病原体是一种大型双链DNA病毒，即WSSV，它可能是一个新属的代表，暂称为Whispovirus。从先前构建的台湾WSSV分离株的WSSV基因组文库中，鉴定出了具有开放阅读框（ORF）的克隆，这些开放阅读框编码的蛋白质与I类核糖核苷酸还原酶大亚基（RR1）和小亚基（RR2）具有显著同源性。WSSV的rr1和rr2分别可能编码848和413个氨基酸。在感染后的不同时间从感染WSSV的虾中分离RNA，并用rr1和rr2特异性核糖探针进行Northern印迹分析，分别发现了2.8 kb和1.4 kb的主要转录本。5' RACE显示，主要的rr1转录本从相对于ATG翻译起始位点-84（C）的位置开始，而rr2基因的转录从核苷酸残基-68（T）开始。观察到一个包含rr1和rr2转录起始位点的共有基序（TCAc/tTC）。Northern印迹和RT-PCR显示，rr1和rr2的转录在感染后4-6小时开始，并持续至少60小时。因此，rr1和rr2基因似乎是WSSV的“早期基因”。
