Title Transcriptional Analysis of the DNA Polymerase Gene of Bombyx mori Parvo-like Virus (China Isolate)
Author Yong-Jie Wang1,2*, Ke-Ping Chen2, Qin Yao2, and Xu Han2
Address 1Institute of Fisheries, Anhui Academy of Agricultural Sciences, Hefei 230031, P. R. China, 2Institute of Life Sciences, Jiangsu University, Zhenjiang 212013, P. R. China
Bibliography Journal of Microbiology, 45(2),139-145, 2007,
DOI
Key Words Bombyx mori parvo-like virus, DNA polymerase gene, conserved motif, transcription analysis
Abstract The Bombyx mori parvo-like virus (China isolate) DNA polymerase (BmDNV-3 dnapol) gene has been tentatively identified based on the presence of conserved motifs. In the present study, we perform a transcriptional analysis of the BmDNV-3 dnapol gene using the total RNA isolated from BmDNV-3 infected silkworm at different times. Northern blot analysis with a BmDNV-3 dnapol-specific riboprobe showed a major transcript of 3.3 kb. 5′-RACE revealed that the major transcription start point was located 20 nucleotides downstream of the TATA box. In a temporal expression analysis using differential RT-PCR, BmDNV-3 dnapol transcript was detected at low levels at 6 h.p.i., increased from 6 to 36 h.p.i., and remained fairly constant thereafter. Analysis of the predicted DNA polymerase sequence using neighborjoining and protein parsimony algorithms indicated that the predicted 1115-residue polypeptide contained five motifs associated with DNA polymerases synthetic activities and three additional motifs associated with polymerases possessing 3′ to 5′ exonuclease activity. The molecular phylogenetic analysis of this gene supported the placement of Bombyx mori parvo-like virus in a separate virus family.
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