Associate Professor Auckland University of Technology Auckland, Auckland, New Zealand
Body of Abstract: The population of lettuce necrotic yellows virus (LNYV), a cytorhabdovirus, comprises two subgroups, SI and SII. The virus is vectored by aphids primarily by Hyperomyzus lactucae. It appears to be endemic to Australia and Aotearoa New Zealand (NZ) but shows different population structures in each country; S1 dominates in NZ, while it appears to have become extinct in Australia. It has been suggested that SII is outcompeting SI, possibly through greater vector transmission efficiency and/or higher replication rate in its host plant or insect vector. Rhabdovirus glycoproteins are important for virus–insect interactions. Analysis of LNYV glycoprotein sequences from NZ shows the same subgroup structure as previous analysis of the nucleocapsid protein. Prediction of the 3D protein structures revealed domain architectures similar to Vesicular Stomatitis Virus (VSV). Importantly, amino acids at positions 244 and 247 of the post-fusion form of the LNYV SII glycoprotein influenced the predicted structure, glycosylation at N248 and the overall stability of the protein. These data support the glycoprotein as having a role in the population differences of LNYV observed between Australia and NZ.