[Defective phages of bacilli: cell parasites or chromosomal components]

A review of data on defective phages of bacilli is presented. The genetics and morphology of this group of phages, the peculiarities of their induction, and data of sequence analysis of the segment of the bacterial chromosome in which the phage genome is localized are considered. It is concluded that the genome of defective phages should probably be considered a part of the bacterial chromosome rather than the genome of a parasite virus of the bacteria.