Fig 7. RNA copy numbers in Culex tarsalis expectorant before and after Vero cell passage.

Mosquito expectorants from all groups were analyzed by qRT-PCR, but only few samples yielded detectable results. For that reason, we additionally passaged all samples once in Vero cells and analyzed supernatants by qRT-PCR to help visualize whether wildtype and COAV997-5nt infectious virus was present in the expectorant. For mixed competition groups (A-C) results were divided into singly and dually infected groups meaning that either one or both viruses were present in the sample. One dot is presented when one virus was detected (singly infected), whereas a black and red dot were assigned to one sample for wildtype and COAV997-5nt RNA, respectively, when both viruses were found in the sample. The total transmission rates for un-passaged and Vero cell passaged expectorants include all positives. In addition, virus-specific transmission rates were calculated individually from both singly and dually infected mosquitoes. Expectorants from singly infected mosquitoes (D-G) are presented as single dots and respective transmission rates are calculated before and after Vero cell passage.