 They play an important role in infecting and causing lysis of members of the genera "Nostoc", "Anabaena" and "Plectonema".The A-group of the virus causes lysis and infects "Anabaena" species.Similarly, the host range of the AN group includes both "Anabaena" and "Nostoc" species; whereas, the N group of viruses infects "Nostoc" species only and includes Cyanophage N-1.