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DEFECTIVE INTERFERING (DI) "genomes are synthesized by nearly all known viruses and represent a vast natural reservoir of antivirals...during successive undiluted passages, the yield of infectious virus cycled from high to low...non-infectious virus particles resulted from large (up to 90%) deletions in one or more of the eight viral genome segments. In the presence of these defective particles the production of infectious virus is severely diminished and this led to the designation of the mutants as defective interfering (DI) viruses." https://lnkd.in/egCZeY2 View in LinkedIn

A WRECK. "Many DI viruses contain deletions so extensive that they do not encode any functional protein. The deletions arise due to errors in replication in which the polymerase carrying out the replication process leaves the template nucleic acid, and either rejoins at a distant point on the same or another template or, in the case of some DI viruses with RNA genomes, switches from the template to copy back along the newly synthesised RNA." https://lnkd.in/egCZeY2 View in LinkedIn

UNIVERSAL. "The production of DI viruses has been demonstrated in almost every virus system studied." https://lnkd.in/egCZeY2 View in LinkedIn

HELPER VIRUS. "DI viruses are defective because the deleted genome lacks an essential gene required for replication. In order to replicate, DI viruses require assistance of the infectious virus from which they were derived, or a genetically compatible related virus, to provide the missing gene products. This is referred to as a helper virus. DI virus production is optimal in the presence of a large amount of helper virus but as the DI virus replicates it reduces the yield of infectious helper virus." https://lnkd.in/egCZeY2 View in LinkedIn

HYPOTHESIS. "One possibility is that DI viruses are evolutionarily important and in natural infections restrict the extent of damage caused to the host while allowing infectious virus to be produced. The host survives the infection and the virus is able to be disseminated to new susceptible hosts." https://lnkd.in/egCZeY2 View in LinkedIn

SAMPLING ARTIFACT. "The detection of DI viruses in vivo is technically difficult as they appear to be generated in only low levels, but DI/defective genomes have recently been reported from infections of a number of vertebrate species including humans." https://lnkd.in/egCZeY2 View in LinkedIn

DEFECTIVE HELP. "The causes of epidemics are much more complicated than we thought...The combination of the defective virus with the normal virus was "more fit" than the normal dengue virus alone." https://lnkd.in/eGjnM8R View in LinkedIn

DEFECTIVE DENGUE VIRUS. "From 2001 to 2002, it went from being quite rare to being in all nine people we sampled that year...Everyone sampled who was getting dengue fever was getting the defective version along with the functional virus. It rose from being rare to being very common in just one year." https://lnkd.in/eGjnM8R View in LinkedIn

DENGUE VIRUS infects some 50-100 million people annually in Southeast Asia, South America and parts of the United States. In 1998, a pandemic of dengue resulted in 1.2 million cases of dengue hemorrhagic fever in 56 countries." Actual fatality 1-4%. https://lnkd.in/eGjnM8R View in LinkedIn

HUBRIS. We forever completely under-estimate the sheer scale of nature's originality. https://lnkd.in/eAvD9w4 View in LinkedIn