FIGURE 2.

SFTSV N and L proteins can interact with heterogenous minigenomes derived from HRTV (but not BUNV) to form functional RNPs. (A) Schematic of the combinatorial minigenome system constructs. Minigenome reporter constructs for L, M, or S segments of HRTV (HV) or BUNV (BV) were generated similarly and termed as HV-M/L/SUTR-luc/EGFP or BV-M/L/SUTR-luc/EGFP, respectively. (B) M segment-based combinatorial minigenome activities within luc reporter system. BHK-21 cells were co-transfected with the indicated minigenome or control plasmids, along with pCAG-SV-L, pCAG-SV-N, and pRL-TK. Forty-eight hours post-transfection, luc activities were measured. Data are shown as mean ± SEM, n = 3. (C) M segment-based combinatorial minigenome activities within EGFP reporter system. Cells were co-transfected with the indicated minigenome or control plasmids, together with pCAG-SV-L and pCAG-SV-N, followed by EGFP expression visualization under fluorescence microscope at 48 h post-transfection. (D,E) SFTSV N and L proteins can also recognize HRTV L and S minigenomes to form functional RNPs. Cells were cotransfected with the indicated viral L (D) or S (E) minigenome transcription plasmids, together with the N and L protein expression plasmids and pRL-TK. Forty-eight hours post-transfection, cells were harvested for measurements of luc activities as described in (B).