Multiplication of Drosophila Hereditary Virus (σ Virus) in Drosophila Embryonic Cells cultivated in vitro

σ VIRUS multiplies in Drosophila and confers to it a characteristic sensitivity to carbon dioxide 1 . Although many data have been collected about this virus, so far all virological and genetic investigations have been concerned with the complex system formed by the virus and the host organism. To understand better the relationships between σ virus and its host at the cellular level, we have been developing techniques to cultivate Drosophila cells in vitro and infect them with σ virus.