- Nucleotide sequence of shallot virus X RNA reveals a 5'-proximal cistron closely related to those of potexviruses and a unique arrangement of the 3'-proximal cistrons. Kanyuka, K.V., Vishnichenko, V.K., Levay, K.E., Kondrikov DYu, n.u.l.l., Ryabov, E.V., Zavriev, S.K. J. Gen. Virol. (1992)