Terminal structure of hypovirulence-associated dsRNAs in the chestnut blight fungusEndothia parasitica

Abstract
The 3'- and 5'-terminal sequences of the five large double-stranded RNA species (L-dsRNA; 4.5–6.0 X 106 daltons) of EP713, a hypovirulent strain of Endothia parasitica, were determined by mobility-shift and enzymatic methods. All the L-dsKNAs appeared to have identical terminal sequences. A heteropolymer sequence was found at one 3'-terminus and a poly(A) sequence of variable length at the other. It was possible to label only one 5'-terminus using polynucleotide kinase and [γ-32p]ATP, and this was shown to be a poly(U) sequence of variable length. We propose that the dsRNAs have the following structure, where X represents a blocking group: