FIG 3.

The 5′ terminus of ttsgR maps to nucleotide position 3772 of TCV gRNA. (a) Step-by-step depiction of the circularization RACE. Note that (i) a non-TCV tag was fused to the 5′ end of the RT primer to enhance the strand specificity; and (ii) the two PCR primers (Tag and 3963F) are back-to-back from each other, and hence, a PCR product is only possible when the template is circularized or in dimeric form. (b) PCR products of both (+) and (−) strands arisen from circularization RACE. The stars on both agarose gels denote nonspecific products present even in mock-treated samples. The primers used are shown to the right. (c) Sequencing results of cloned PCR products (arrows in b) delimit the starting and ending nucleotide of ttsgR. (d) The position of the ttsgR 5′ terminus in a previously identified origin-of-assembly stem-loop within the CP ORF (CPSL).