Figure 9.
The DB lacks resistance to the 5′→3′ exonuclease Xrn1. (A) Xrn1 digest of ZIKV Xrn1-resistant RNA (xrRNA) or ZIKV DB RNA in the presence of 2 mM or 10 mM MgCl2. The upper bands correspond to RNAs with an intact 5′ single-stranded leader that have not been treated with Xrn1. The lower bands correspond to RNA fragments resistant to Xrn1 digestion, in which Xrn1 has removed the 5′ single stranded linker leaving the resistant fragment behind. The position on the gel where a 100 nucleotide RNA standard migrated to is marked as indicated. (B) Upper panel: the 3′ UTR of ZIKV highlighting the position that northern blot DNA probes hybridize to for probe 1 (red) and probe 2 (cyan). Lower panel: northern blots from identical mock (m) and ZIKV infected (ZV) cellular RNA probed with either probe 1 or probe 2. Blots were also probed with a DNA oligo hybridizing with the U6 snRNA as a loading control. Positions of the genomic RNA (gRNA) and subgenomic flaviviral RNAs (sfRNAs) are as labeled. Cartoon diagrams of sfRNA1, sfRNA2, and sfRNA3 are shown.