Figure A1. Maximum-likelihood tree for a 490-nt section of the Gn glycoprotein gene of 111 isolates and derived strains of Rift Valley fever virus from Africa and Saudi Arabia, 1944–2010. The 95 unique sequences sorted into 15 lineages (A–O). Mean pairwise distances (p-distances) were <0.017 within lineages, and bootstrap values were >70%. Scale bar indicates substitutions per site. CAR, Central African Republic; SNS, Smithburn neurotropic strain.