Transcriptional analysis of the ribonucleotide reductase genes of shrimp white spot syndrome virus.
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."
Tsai
M F
MF
Department of Zoology, Institute of Biochemistry, Taipei, Taiwan.
Lo
C F
CF
van Hulten
M C
MC
Tzeng
H F
HF
Chou
C M
CM
Huang
C J
CJ
Wang
C H
CH
Lin
J Y
JY
Vlak
J M
JM
Kou
G H
GH
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D004267:DNA Viruses / Q000201:enzymology* / Q000235:genetics* / Q000302:isolation & purification; D033364:Decapoda / Q000821:virology*; D007527:Isoenzymes / Q000235:genetics; D008969:Molecular Sequence Data; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012264:Ribonucleotide Reductases / Q000235:genetics*; D014158:Transcription, Genetic
D007527:Isoenzymes; D012264:Ribonucleotide Reductases