Characterization of the non - coding regions of the 1 1918 influenza A H 1 N 1 virus

28 The terminal non-coding region (NCR) sequences of the eight gene segments of the influenza 29 A/Brevig Mission/1/1918 (H1N1) virus were determined by rapid amplification of cDNA ends 30 (RACE). Chimeric viruses encoding the open reading frames of the 1918 virus but flanked by 31 either the wild-type 1918 NCR sequences, or the NCR sequences of two other H1N1 virus 32 strains, A/WSN/1933 and A/New York/312/2001 were produced. No growth differences 33 between the NCR variant 1918 influenza viruses were noted. 34 35 36 37 Influenza A viruses are significant pathogens of humans and animals (1). In humans, influenza 38 A viruses cause annual epidemics and occasional pandemics. The worst pandemic on record, the 39 ‘Spanish’ influenza pandemic of 1918-1919 resulted in the deaths of approximately 50 million 40 people (2). While attempts to characterize the causative agent of the pandemic were made in 41 1918, no successful viral isolates were made; consequently the virus was only characterized 42 using an archaevirological approach by overlapping RT-PCR of small RNA fragments from 43 1918 post-mortem lung tissue samples (3). Using this approach, the complete 1918 viral genome 44 coding sequences were determined, but the terminal non-coding region (NCR) sequences were 45 not reported as consensus viral NCR primers were used in the amplification of the 5’ and 3’ ends 46 of the coding regions of each segment (4-9). The complete coding sequence of the 1918 47 influenza A virus (1918 virus) hemagglutinin (HA) gene was determined from a formalin-fixed, 48 paraffin-embedded 1918 post-mortem lung tissue sample [A/South Carolina/1/1918 (H1N1)] 49 with partial HA sequence from several other cases (5, 10, 11). The coding sequences of the 50 on D ecem er 5, 2017 by gest http/jvi.asm .rg/ D ow nladed fom