[Isolation of Drosophila melanogaster cell lines of different genotypes and study of multiplication of two variants of sigma rhabdovirus in those lines (author's transl)].

Strains of sigma virus which are called P- do not multiply in Drosophila strains called Paris, homozygous for the Pp allele of gene ref(2)P. Adsorption is normal and the virus is not destroyed. It seems that the viral function concerned is an early one. P+ variants isolated from a P- population do multiply in flies from the Paris strain. Three continuous cell lines homozygous for the Pp allele and one homozygous for the Po allele were isolated. Several attempts to infect those cell lines with P- and P+ variants of sigma virus were done. Cultures homozygous for the Pp allele reacted differently whether infection was initiated with P+ or P- viral strains, while cultures homozygous Po/Po gave the same result with both viral strains. Similarity between results obtained with two independent P- viral strains leads to the conclusion that the ref (2) P gene is active in cells from continuous cell lines; its Pp allele does not allow multiplication of P- viral types. An interpretation of the slight multiplication observed with concentrated inoculum is discussed.