title: Analysis of the genome of a Korean isolate of the Pieris rapae granulovirus enabled by its separation from total host genomic DNA by pulse-field electrophoresis.
abstract: BACKGROUND
  Most traditional genome sequencing projects involving viruses include the culture and purification of the virus particles. However, purification of virions may yield insufficient material for traditional sequencing. The electrophoretic method described here provides a strategy whereby the genomic DNA of the Korean isolate of Pieris rapae granulovirus (PiraGV-K) could be recovered in sufficient amounts for sequencing by purifying it directly from total host DNA by pulse-field gel electrophoresis (PFGE).
  
  
  RESULTS
  The total genomic DNA of infected P. rapae was embedded in agarose plugs, treated with restriction nuclease and methylase, and then PFGE was used to separate PiraGV-K DNA from the DNA of P. rapae, followed by mapping of fosmid clones of the purified viral DNA. The double-stranded circular genome of PiraGV-K was found to encode 120 open reading frames (ORFs), which covered 92% of the sequence. BLAST and ORF arrangement showed the presence of 78 homologs to other genes in the database. The mean overall amino acid identity of PiraGV-K ORFs was highest with the Chinese isolate of PiraGV (~99%), followed up with Choristoneura occidentalis ORFs at 58%. PiraGV-K ORFs were grouped, according to function, into 10 genes involved in transcription, 11 involved in replication, 25 structural protein genes, and 15 auxiliary genes. Genes for Chitinase (ORF 10) and cathepsin (ORF 11), involved in the liquefaction of the host, were found in the genome.
  
  
  CONCLUSIONS
  The recovery of PiraGV-K DNA genome by pulse-field electrophoretic separation from host genomic DNA had several advantages, compared with its isolation from particles harvested as virions or inclusions from the P. rapae host. We have sequenced and analyzed the 108,658 bp PiraGV-K genome purified by the electrophoretic method. The method appears to be generally applicable to the analysis of genomes of large viruses.
authors.affiliation: Division of Plant Biotechnology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju, South Korea.
authors.forename: Yong Hun
authors.initials: YH
authors.lastname: Jo
authors.affiliation: Division of Plant Biotechnology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju, South Korea.
authors.forename: Bharat Bhusan
authors.initials: BB
authors.lastname: Patnaik
authors.affiliation: Department of Life Science and Biotechnology, College of Natural Sciences, Soonchunhyang University, Asan, South Korea.
authors.forename: Se Won
authors.initials: SW
authors.lastname: Kang
authors.affiliation: GnC Bio Company Limited, Daejeon, South Korea.
authors.forename: Sung-Hwa
authors.initials: SH
authors.lastname: Chae
authors.affiliation: Division of Plant Biotechnology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju, South Korea.
authors.forename: Seunghan
authors.initials: S
authors.lastname: Oh
authors.affiliation: Division of Plant Biotechnology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju, South Korea.
authors.forename: Dong Hyun
authors.initials: DH
authors.lastname: Kim
authors.affiliation: Division of Plant Biotechnology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju, South Korea.
authors.forename: Mi Young
authors.initials: MY
authors.lastname: Noh
authors.affiliation: Division of Plant Biotechnology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju, South Korea.
authors.forename: Gi Won
authors.initials: GW
authors.lastname: Seo
authors.affiliation: Hampyeong County Insect Institute, Hampyeong County Agricultural Technology Center, Hampyeong, South Korea.
authors.forename: Heon Cheon
authors.initials: HC
authors.lastname: Jeong
authors.affiliation: Hampyeong County Insect Institute, Hampyeong County Agricultural Technology Center, Hampyeong, South Korea.
authors.forename: Ju Young
authors.initials: JY
authors.lastname: Noh
authors.affiliation: Department of Life Science and Biotechnology, College of Natural Sciences, Soonchunhyang University, Asan, South Korea.
authors.forename: Ji Eun
authors.initials: JE
authors.lastname: Jeong
authors.affiliation: Department of Life Science and Biotechnology, College of Natural Sciences, Soonchunhyang University, Asan, South Korea.
authors.forename: Hee Ju
authors.initials: HJ
authors.lastname: Hwang
authors.affiliation: Department of Medicine, Medical Research Institute, College of Medicine, Chung-Ang University, Seoul, South Korea.
authors.forename: Kisung
authors.initials: K
authors.lastname: Ko
authors.affiliation: Division of Plant Biotechnology, College of Agriculture and Life Sciences, Chonnam National University, Gwangju, South Korea.
authors.forename: Yeon Soo
authors.initials: YS
authors.lastname: Han
authors.affiliation: Department of Life Science and Biotechnology, College of Natural Sciences, Soonchunhyang University, Asan, South Korea.
authors.forename: Yong Seok
authors.initials: YS
authors.lastname: Lee
mesh_terms: D000818:Animals; D001483:Base Sequence; D002080:Butterflies / Q000821:virology*; D002458:Cell Fractionation; D017931:DNA Primers / Q000235:genetics; D004279:DNA, Viral / Q000302:isolation & purification*; D016521:Electrophoresis, Gel, Pulsed-Field / Q000379:methods*; D025722:Granulovirus / Q000235:genetics*; D008969:Molecular Sequence Data; D056910:Republic of Korea; D017422:Sequence Analysis, DNA
chemical_list: D017931:DNA Primers; D004279:DNA, Viral