http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Investigations into the replication, structure, and expression of the Campoletis sonorensis virus genome
The polydnavirus Campoletis sonorensis Virus (CsV) is known to infect m any tissues of the parasitized host larvae Heliothis virescens. Even though expression of CsV is known to occur in H. virescens tissue no replication has been observed. In this study CsV DNA was analyzed in H. virescens tissue using sensitive molecular hybridization techniques. The results showed that in naturally parasitized or calyx fluid injected H. virescens larvae, no increase in the level of viral DNA could be detected for the entire period of endoparasite development. Replication could only be detected in late pupal and adult stages of C. sonorensis wasps. These results suggest that CsV does not replicate in H. virescens larvae and may be restricted to the tissues of C. sonorensis which has novel implications with respect to the life cycle of this virus. To obtain defined probes for analysis of viral transcription superhelical (SH) CsV DNAs were cloned and partially physically characterized. Five SH clones from the B, H, M, O^1 and W regions of the CsV genome were analyzed for sequence relationships with respect to the rest of the CsV genome. All of the DNAs were found to cross-hybridize to multiple regions in the CsV genome. In addition, there was an increase in the number of regions to which cross-hybridization was observed if the stringency of hybridization was reduced. On SH-B, H, and O^1 an imperfectly conserved repeat sequence was identified and sequenced and was shown to have an average size of 540 bp. The repeat elements were arranged singly or in direct tandem arrays. These results show that the CsV genome is comprised of interrelated SH DNAs that may have arisen by multiple recombinational events and sequence divergence. Each of the cloned SH DNAs were used to analyze viral transcription in the C. sonorensis female reproductive tracts and it was shown that CsV is expressed in the adult female w asp. This is the first report to identify viral transcripts in the w asp host. Comparison of mRNAs expressed in either C. sonorensis or in parasitized H. virescens homologous to the five SH DNAs, showed that for SH-B, M, and W, different transcripts were expressed in each host...
Includes bibliographical references (leaves 113-127).