A major rearrangement of the VP6 gene of a strain of rotavirus provides replication advantage

Rotavirus Rearranged Genomic RNA Segments Are Preferentially Packaged into Viruses Despite Not Conferring Selective Growth Advantage to Viruses

“…For competitive experiments, we have chosen to perform serial passages in cell culture at high MOI (undiluted inoculum) to favor co-infection of cells by both r-RV and wt-RV. Under these conditions, our findings are in agreement with those of previous studies that report the selection of r-RV over wt-RV in the course of mixed infection for a bovine r-RV (strain brvA) with a rearranged segment 5 [11], a porcine r-RV (strain CC86) with a rearranged segment 11 [30], and a reassortant human r-RV (strain C11) carrying a bovine rearranged segment 6 [31]. Taken together, lack of growth advantage conferred by rearranged segments to r-RV, combined with the constant selection of rearranged segments in viral progenies, strongly suggests a preferential segregation of rearranged segments rather than an overgrow of r-RV over wt-RV during viral replication.…”

“…Prior studies have reported similar results for bovine or porcine RV carrying rearranged segment(s) [11], [19], [30], [31]. In a cell-free RV replication system, Patton et al have shown that a size increase of the RNA template has a strong negative influence on dsRNA synthesis by open cores.…”

“…Rotaviruses carrying rearranged segment(s) (r-RV) can package up to 10% additional bp without morphological modification [34] nor being defective, since r-RV can be isolated by limit dilution or plaque methods [11], [12], [16], [29], [31]. However, the impact of gene rearrangement on viral replication efficiency is not fully understood.…”

“…This could be hypothesized, since several studies have reported the possibility of obtaining viable reassortant viruses that have inherited a rearranged segment derived from a different genetic background [29], [31], [36], [37]. By performing competitive experiments between human r-RV and the bovine wt-RV strain RF, chosen for its major growth advantage over human RV, we show here that rearranged segments 7 and/or 11 of the human RV also underwent preferential segregation in the heterologous genetic background of the bovine RV, replacing the wt segment in the viral progenies.…”

“…It has been reported that selection of r-RV over wt-RV can occur during serial passages in cell culture [11], [29]–[31], although it may depend on the MOI [11]. However, it is unknown whether selection of r-RV over wt-RV is due to a selective growth advantage of the virus or to a selective packaging advantage of the rearranged segments.…”