Fig. 3From: Characterization of novel Bovine Leukemia Virus (BLV) antisense transcripts by deep sequencing reveals constitutive expression in tumors and transcriptional interaction with viral microRNAsBLV 3′LTR antisense promoter activity and regulatory sequences affecting transcription. a Ideogram showing the three constructs used in luciferase assays, 5′LTR orientation, 3′LTR orientation and 3′LTR orientation with the majority of the U3 deleted (3′∆). Transcription factor binding sites from [24]. b Luciferase levels for the 5′LTR, 3′LTR and 3′∆ constructs. Comparison between the three constructs showed a significant difference among all three (p value <0.0001). c 5′LTR construct alone and co-transfected with a wild type (wt) Tax and transactivation deficient Tax (mut), which carries a E-to-K amino acid change at position 303 [39]. Tax wt caused a significant increase in luciferase levels (p value <0.0001). d Same as c but using the 3′LTR construct. Tax produced a significant (p value <0.001) drop in luciferase levels. e 5′LTR construct, mutation of IRF resulted in a modest but non significant drop in expression. Mutating DAS resulted in a statistically significant (p value <0.01) decrease (in line with previous reports). For 3′LTR, mutation in IRF caused modest, but non significant drop in expression, mutating DAS resulted in a significant drop (p value <0.0001). In the 3′∆ construct, mutating IRF and DAS caused a significant (p value <0.0001) decrease in luciferase levels (Luciferase levels are scaled to the left most construct in b, c and d. In E they were scaled to the appropriate wild type construct. Statistical significance was determined via Tukey’s multiple comparisons test, **p value <0.01; ***p value <0.001; ****p value <0.0001)Back to article page