Comparative transient expression assay analysis of hycu-hr6- and IE1-dependent regulation of baculovirus gp64 early promoters in three insect cell lines.

We previously demonstrated that the Hyphantria cunea multicapsid nucleopolyhedrovirus (HycuMNPV) gp64 gene (hycu-gp64) is uniquely localized on the viral genome with a large homologous region of 1582bp, hycu-hr6, immediately upstream of the hycu-gp64 gene. In the present study, we compared the regulation of gp64 early promoters from HycuMNPV, Autographa californica multicapsid NPV (AcMNPV) and Bombyx mori NPV (BmNPV) by cis-acting hycu-hr6 and trans-acting IE1s in three cell lines (Spodoptera frugiperda Sf9, Bombyx mori BM-N and Spilosoma imparilis SpIm). A transient expression assay with plasmids harboring a reporter luciferase gene demonstrated that the gp64 early promoters are positively regulated by hycu-hr6, independent of virus and cell types.

Euprosterna elaeasa virus genome sequence and evolution of the Tetraviridae family: emergence of bipartite genomes and conservation of the VPg signal with the dsRNA Birnaviridae family.

The Tetraviridae is a family of non-enveloped positive-stranded RNA insect viruses that is defined by the T=4 symmetry of virions. We report the complete Euprosterna elaeasa virus (EeV) genome sequence of 5698 nt with no poly(A) tail and two overlapping open reading frames, encoding the replicase and capsid precursor, with approximately 67% amino acid identity to Thosea asigna virus (TaV). The N-terminally positioned 17 kDa protein is released from the capsid precursor by a NPGP motif.

hycu-hr6, A large homologous region of the Hyphantria cunea nucleopolyhedrovirus genome, as a powerful and versatile enhancer in insect expression systems.

We previously identified a large homologous region (hr), hycu-hr6, in the genome of the Hyphantria cunea nucleopolyhedrovirus (HycuNPV) and suggested that hycu-hr6 was the largest baculovirus promoter enhancer hr identified so far. In this study, we examined the enhancement activity of hycu-hr6 against two promoters from constitutive baculovirus immediate early genes, the HycuNPV ie1 (hycu-ie1) and the Orgyia pseudotsugata multicapsid (M) NPV ie2 (op-ie2), and against a promoter from the inducible Drosophila heat shock protein 70 gene (hsp70) in five lepidopteran (BmN-4, Ld652Y, Sf9, SpIm, and TN368) and one dipteran (S2) insect cell lines. Comparative analyses of transient expression assays using the firefly luciferase gene (luc) as a reporter showed that hycu-hr6 enhanced the activity of all three promoters in all tested cell lines.

Epidemiology, relative invasive ability, molecular characterization, and competitive performance of Campylobacter jejuni strains in the chicken gut.

One hundred forty-one Campylobacter jejuni isolates from humans with diarrhea and 100 isolates from retailed poultry meat were differentiated by flaA typing. The bacteria were isolated in a specific geographical area (Dunedin) in New Zealand over a common time period. Twenty nine flaA types were detected, one of which (flaA restriction fragment length polymorphism type 15 [flaA-15]) predominated among isolates from humans ( approximately 30% of isolates).

Host range factor 1 from Lymantria dispar Nucleopolyhedrovirus (NPV) is an essential viral factor required for productive infection of NPVs in IPLB-Ld652Y cells derived from L. dispar.

Host range factor 1 (HRF-1) of Lymantria dispar multinucleocapsid nucleopolyhedrovirus promotes Autographa californica MNPV replication in nonpermissive Ld652Y cells derived from L. dispar. Here we demonstrate that restricted Hyphantria cunea NPV replication in Ld652Y cells was not due to apoptosis but was likely due to global protein synthesis arrest that could be restored by HRF-1.

Identification and characterization of Hyphantria cunea nucleopolyhedrovirus homologous repeated regions.

A total of six homologous regions (hycu-hrs1-6) were identified in the genome of Hyphantria cunea nucleopolyhedrovirus (HycuNPV). These hycu-hrs were localized in non-coding regions interspersed throughout the HycuNPV genome and showed structural homology to several other baculovirus hrs. Sequence analyses indicated that hycu-hrs were composed of 65-69-bp direct repeats, each of which contained a 29-31-bp imperfect palindrome embedded within non-palindromes tandemly arranged.

Induction of apoptosis in an insect cell line, IPLB-Ld652Y, infected with nucleopolyhedroviruses.

Ld652Y cells derived from the gypsy moth, Lymantria dispar, were infected with seven different nucleopolyhedroviruses (NPVs) including those from Autographa californica, Bombyx mori (BmNPV), Hyphantria cunea (HycuNPV), Spodoptera exigua (SeMNPV), L. dispar, Orgyia pseudotsugata (OpMNPV) and Spodoptera litura (SpltMNPV). The results showed that Ld652Y cells infected with BmNPV, HycuNPV, SeMNPV, OpMNPV and SpltMNPV underwent apoptosis, displaying apoptotic bodies, characteristic DNA fragmentation and increased caspase-3-like protease activity; HycuNPV induced the most severe apoptosis.