Tomato DNA contains no detectable regions complementary to potato spindle tuber viroid as assayed by solution and filter hybridization

• Published in: Virology (New York, N.Y.) Vol. 104; no. 1; pp. 1 - 9
• Main Authors: Zaitlin, Milton, Niblett, C.L., Dickson, Elizabeth, Goldberg, R.B.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.01.1980
• ISSN: 0042-6822; 1096-0341
• DOI: 10.1016/0042-6822(80)90361-X

A previous report (Hadidi et al. (1976) Proc. Nat. Acad. Sci. USA 73, 2453–2457) has suggested that potato spindle tuber viroid (PSTV) RNA contains sequences complementary to the DNA of its host and, to a lesser extent, to the DNA of some nonhost species. Our studies indicate, however, that the apparent hybridization between 125I-labeled PSTV and tomato DNA which can be observed in both solution and filter hybridization experiments is a consequence of the hybridization of host RNAs (mostly ribosomal) which are minor contaminants of the polyacrylamide gel-purified viroid preparations. When the level of these contaminants is reduced by further purification of the viroid in gels containing 8 M urea, no hybridization to tomato DNA could be detected. Thus, if sequence homology exists, it must be very minimal and its detection is beyond the capabilities of the methods employed.