FIRST OF IT'S KIND DISCOVERY- LATCHING OF VIRUS ON VIRUS

 

(represenative TEM images of Mulch and Flayer systems)

The first observation of a satellite bacteriophage (a virus that infects bacterial cells) consistently attaching to a helper bacteriophage at its "neck" -- where the capsid joins the tail of the virus.Satellites are genetic components that are mobile and reliant on their helper viruses' replication machinery. Satellite nucleic acids that use their helper morphogenic genes for propagation have been demonstrated in numerous instances by bacteriophages. the Flayer and Mulch satellite-helper phage systems, which infect Streptomyces species are the new example of bacteriophage satellite viruses since the satellites encode for encapsidation machinery but lack important replication genes. Additionally, the helpers' tRNA gene content corresponds with the satellites' codon usage. 

Among these systems is Flayer, the first instance of a pathogenic satellite phage, whose satellite does not seem to integrate into the host genome. Due to a special adaption on its tail, the Flayer satellite can cling to its helper and co-infect simultaneously. In the evolutionary arms race between satellite and helper phages, these data show an ever-widening variety of satellite tactics for genetic dependence on their helpers. This finding paves the way for deeper research to determine the satellite's mechanism of attachment, the frequency of this phenomena, and many other details. 

References:

• deCarvalho, T., Mascolo, E., Caruso, S.M. et al. Simultaneous entry as an adaptation to virulence in a novel satellite-helper system infecting Streptomyces species. ISME J (2023). https://doi.org/10.1038/s41396-023-01548-0