The anaerobic spirochete @entity2127 is host to a bacteriophage-like agent known as VSH-1. VSH-1 is a novel gene transfer mechanism which does not self-propagate and transfers random 7.5kb fragments of host DNA between @entity2127 cells. In these investigations early events during VSH-1 induction by @entity1138 were examined. Quantitative PCR analysis revealed that VSH-1 hvp38 and hvp53 genes did not detectably increase in copy numbers during induction. Based on Northern blot hybridization assays, transcription of VSH-1 genes hvp38, hvp53, hvp45, hvp101, and lys increased fivefold to tenfold between 2 and 4h after induction whereas mRNA levels for @entity2127 flaA1 declined over the same time period. @entity2755 prevented the @entity1138 -induced increases in VSH-1 gene transcription. @entity273 (300muM) substituted for @entity1138 as an inducer of VSH-1 gene transcription and is a possible 'natural' inducer of VSH-1 production in vivo. Northern blot hybridization, RT PCR, and primer extension analyses showed that VSH-1 genes are co-transcribed at an initiation site upstream of the VSH-1 gene operon. Two direct heptanucleotide repeats (ACTTATA) were identified between the putative -35 and -10 positions of the VSH-1 gene operon and are likely to represent a binding site for transcription proteins. These findings indicate VSH-1 virion production does not require genome replication, consistent with the inability of VSH-1 to self-propagate. Early events in VSH-1 induction include de novo synthesis of protein(s) essential for transcription of VSH-1 genes as polycistronic mRNA initiating upstream of the hvp45 gene.

Induction and transcription of VSH-1, a prophage-like gene transfer agent of XXXX .

@entity273 :: ('MESH:D006861', 'Chemical') :: ['Hydrogen peroxide'] @entity1138 :: ('MESH:D016685', 'Chemical') :: ['mitomycin C'] @entity2755 :: ('MESH:D002701', 'Chemical') :: ['Chloramphenicol'] @entity2127 :: ('159', 'Species') :: ['B. hyodysenteriae', 'Brachyspira hyodysenteriae']
@entity2127 :: (159,Species) :: ['Brachyspira hyodysenteriae']
