Does reassortment cause antigenic shift?
Reassortment can result in antigenic shift when an intermediate host, such as a pig, is simultaneously infected with a human and an avian influenza A virus.
What is the reassortment of influenza?
Reassortment is the process by which influenza viruses swap gene segments. This genetic exchange is possible due to the segmented nature of the viral genome and occurs when two differing influenza viruses co-infect a cell.
What is genetic reassortment?
Genetic reassortment, the mixing of genes between two organisms to make a new genetic sequence known as a recombinant, is a powerful mechanism for evolution and adaptation. Sexual reproduction genetically recombines the genes of each parent. Each human is a recombinant of the parents’ genes.
What is genetic shift in influenza virus?
Another type of change is called “antigenic shift.” Shift is an abrupt, major change in a flu A virus, resulting in new HA and/or new HA and NA proteins in flu viruses that infect humans. Antigenic shift can result in a new flu A subtype.
What causes antigenic shift influenza?
Antigenic shift is a more major change in the influenza virus. This shift typically occurs when a human flu virus crosses with a flu virus that usually affects animals (such as birds or pigs). When the viruses mutate, they shift to create a new subtype that is different from any seen in humans before.
What is mechanism of genetic reassortment in viruses?
2.2 Reassortment Reassortment of segmented RNA viruses is a mechanism by which cognate genome segments are exchanged in progeny viruses upon infection of a single cell by two or more closely related virus strains. When these viruses contain different cogent genes, new genotype constellations may emerge.
What causes antigenic shift?
Antigenic shift occurs when a nonhuman influenza virus directly infects human hosts or when a new virus is generated by genetic reassortment between nonhuman and human influenza viruses.
What does genomic reassortment mean in terms of viruses?
Virus reassortment, or simply reassortment, is a process of genetic recombination that is exclusive to segmented RNA viruses in which co-infection of a host cell with multiple viruses may result in the shuffling of gene segments to generate progeny viruses with novel genome combinations (Fig 1A) [1].
Which viruses can undergo reassortment?
In theory, any virus with a segmented genome can undergo reassortment. Among viruses that infect vertebrates, those that carry segmented genomes belong to the Arenaviridae, Birnaviridae, Bunyavirales, Orthomyxoviridae, Picobirnaviridae, and Reoviridae.
When two different influenza viruses infect the same cell their segmented genomes can undergo reassortment which will result in?
Because influenza virus genomes are formed by 8 separate pieces of RNA (called “genome segments”), sometimes these viruses can “mate,” in a process called, “reassortment.” During reassortment, two influenza viruses’ genome segments can combine to make a new strain of influenza virus.