Verma, O. P.Pokhriyal, Mayank2016-12-142016-12-142016http://krishikosh.egranth.ac.in/handle/1/9017310PHBT108- Validation of Transcription Factors Responsible for Concerted Expression of IE genes of BHV-1- 2016Bovine herpesvirus-1 (BoHV-1) is an important member of the Herpesviridae family. The lytic cycle of BoHV-1 progress through three stages of viral transcription. The first stage, immediate-early (IE), does not require prior viral gene expression and is essential for the second, early (E), and third, late (L), stages of the cycle. Like other herpesviruses, BoHV-1 creates a lifelong latency in sensory neurons of trigeminal ganglia. Reactivation from latency leads to triggers of the transcription cascade. IE genes are important class of genes for the BoHV-1 replication. IE genes which are transcribed from two different immediate early transcription units; immediate early transcription unit I (IETU1) encoding BICP0 and BICP4 sharing common promoter and transcription unit II(IETU2) encoding BICP 22. Contrary to this we found that the transcripts of BICP0 and BICP4 are transcribed by two different TATA less promoters.The BICP0 and BICP4 also show different levels of expression. Realtime PCR revealed that expression level of BICP4 continuously declines after attaining a peak level at 1hr while BICP0 show biphasic expression supporting the earlier observation that it is expressed from two different promoters. These promoters of immediate early genes are well characterized but still the transcription factors involved in the concerted expression of immediate early genes of BoHV-1 are unknown. Evidence is provided for the existence of three other immediate early genes i.e. UL21, UL33 and UL 34 in BoHV-1. These genes are expressed in the presence of cycloheximide and show a similar expression profile as BICP0, BICP22 and BICP4. The promoters of these genes have TATA box at optimal site, lack OCT-1 factor but show similar spatial placement of C/ EBPα, DPE and Inr elements. The TATA box present in optimal position make the basal promoter of UL21, UL33 and UL34 stronger than the promoters of BICP0, BICP4 and BICP22. Also role of OCT-1, is not essential in the coordinated expression of IE genes in BoHV-1 infection as it is for HSV-1.enThesis