INVESTIGATION OF IN VIVO INTEGRATION OF GLYPTAPANTELES INDIENSIS POLYDNAVIRUS (GIBV) DNA IN LEPIDOPTERAN HOST CHROMOSOMAL DNA

Authors: Gundersen-Rindal, Dawn; Pedroni, Monica

Submitted to: American Society for Virology Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 7/10/2004
Publication Date: 7/10/2004
Citation: Gundersen, D.E., Pedroni, M.J. 2004. Investigation of in vivo integration of glyptapanteles indiensis polydnavirus (gibv) dna in lepidopteran host chromosomal dna. American Society for Virology Meeting. American Soceity for Virology Meeting Montreal, Quebec ,CANADA 7/10/04-7/14/04.

Interpretive Summary:

Technical Abstract: Investigation of in vivo integration of Glyptapanteles indiensis polydnavirus (GiBV) DNA in lepidopteran host chromosomal DNA. Dawn Gundersen-Rindal and Monica J. Pedroni U.S. Department of Agriculture, Agricultural Research Service, Insect Biocontrol Laboratory, Beltsville, MD 20705. Previous examination of the long-term persistence of polydnavirus (PDV) DNA in infected lepidopteran cell cultures showed some of the virus genome became integrated permanently into the lepidopteran cell genome. Junction clones containing both insect chromosomal and polydnavirus sequences were isolated from Lymantria dispar (gypsy moth) cell lines that had been maintained in continuous culture for more than five years post infection with the braconid Glyptapanteles indiensis PDV (GiBV). Integration junction sites were identified by sequence comparison of linear (integrated) and circular forms of the GiBV genome segment F, from which the viral sequences originated. Specific PCR primers were designed around these in vitro integration sites and used to investigate potential in vivo integration. Southern blot data showed GiBV sequences were detectable in chromosomal regions of DNA extracted from L. dispar larvae that had been manually injected with filtered GiBV-containing calyx fluid. For PCR, DNA was extracted at different time points post injection from larval hemocytes and somatic tissues. The expected junction sequences containing GiBV and Ld chromosomal sequences were amplified by PCR from somatic tissue DNA of these larvae at 14 and 20 days post injection. A modified transposon display technique was used to survey and identify viral insertions to examine the nature of GiBV integration in L. dispar cells in vitro and in vivo. Collectively, the data support the occurrence of in vivo integration of PDV DNA and suggest some similarity of PDV with transposable elements.