The Growth of Two Togaviruses in Cultured Mosquito and Vertebrate Cells

SUMMARY In cultured Aedes albopictus cells at 28 °C, Semliki Forest virus (SFV, an alphavirus; Wildy, I971) shows a latent period, growth rate and yield per cell similar to that obtained with the same virus in three vertebrate cell lines at 37 °C. SFV and the flavivirus Kunjin both grow more slowly and to lower titre in A. aegypti cells (Peleg, I968 ) than in A. albopictus cells. Kunjin grows more slowly than SFV in both mosquito and vertebrate cell lines. No replication of either virus occurred in another A. aegypti cell line (Grace, t966). The effect of adsorption conditions on the percentage of Aedes albopictus cells infected by SFV is examined. In both mosquito and Vero cells the temperature giving the shortest latent period of SFV growth is close to the optimal temperature for cell growth. No c.p.e, were visible in infected mosquito cells; this contrasts with the invariant destruction of vertebrate cells.