Sequence‐specific priming of the in vitro synthesis of DNA complementary to citrus exocortis viroid

Correlation between structure and pathogenicity of potato spindle tuber viroid (PSTV)

“…The abbreviations for the isolates are either related to the names of the investigators who provided the original culture [DI: Dr T.O.Diener, Belstville, MD, (Diener, 1971) (Harris and Browning, 1980)], to the country from which they came (E: England) or the country in combination with the virulence of the isolate (DS: Dutch, severe isolate). PS7V-specific DNA primers and their chemical synthesis Previous studies have shown that despite its highly base-paired secondary structure, PSTV RNA can be reversely transcribed into cDNA molecules in the size range of full length if appropriate DNA primers are used (Rohde et al, 1981a(Rohde et al, , 1981b. Two out of three primers (p14I and p1511) were chosen so that they would bind to the central region of the molecule which is strictly conserved in three viroid 'species' PSTV, CEV and CSV (Gross et al, 1982).…”

Affinity chromatography of viroid RNAs

“…In a second purifica.tion step the batchwise eluted RNA is readsorbed onto a PNI~ column and eluted by a LiCt/urea gradient as described above. Viroid R N A with a degree of p u r i t y sufficient for sequence-specific priming of c D N A synthesis [8,9] m a y be r a p i d l y obtained when a PNR-em~iehed fraction (step 1) is readsorbed without recycling which prevents q u a n t i t a t i v e binding of cellular tKNAs. Only fully renatured viroid RNAs show the chromatographic properties as depicted in Fig.…”