Is reassortment a type of recombination?
Reassortment is a form of genetic recombination that occurs in RNA viruses with segmented genomes, regardless of whether they are single- or double-stranded and whether these involve few or many segments.
What are the types of genetic recombination?
There are two classes of genetic recombination: general, or homologous, and site-specific. Inhomologous recombination an exchange of genetic material takes place between two pairs of homologous DNA sequences located on two copies of the same chromosome.
What is reassortment vaccine?
Reassortant vaccines are manufactured by taking advantage of the natural ability of viruses with segmented genomes to reassort when more than one strain is infecting the host cell.
How does influenza reassortment work?
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 meant by genomic reassortment?
Reassortment is exclusively seen in viruses with a segmented genome. It is defined as the exchange of intact genes within the entire segment, which occurs during coinfection. Reassortment has been observed in Bunyaviridae, Reoviruses, arenavirus, and Orthomyxoviruses.
Is reassortment antigenic drift?
Human influenza A viruses evolve rapidly by antigenic shift and antigenic drift. Antigenic shift occurs by gentic reassortment between currently circulating human viruses and influenza viruses of other origin and by re-emergence of a previously circulating virus.
What is recombination discuss the different types of recombination?
General or homologous recombination occurs between DNA molecules of very similar sequence, such as homologous chromosomes in diploid organisms. General recombination can occur throughout the genome of diploid organisms, using one or a small number of common enzymatic pathways.
Is there a difference between genetic recombination and crossing over?
The main difference between recombination and crossing over is that recombination is the production of different combinations of alleles in the offspring whereas crossing over is the exchange of genetic material between non-sister chromatids, the event which produces recombination.
What causes genetic reassortment?
Viruses do not have a cell and are dependent on the cells they invade to reproduce. However, viruses can create recombinants via a process called genetic reassortment. If two of the same type of virus enter a single cell the genes may genetically reassort, resulting in recombinants.
Does reassortment occur in Rota virus?
Rotaviruses (RVs) can evolve through the process of reassortment, whereby the 11 double-stranded RNA genome segments are exchanged among strains during co-infection. However, reassortment is limited in cases where the genes or encoded proteins of co-infecting strains are functionally incompatible.
Why is reassortment an important process in the evolution of influenza viruses?
Reassortment is the process by which influenza viruses, which carry RNA genomes comprising eight segments, exchange genetic material. Reassortment of the genome segments of two differing influenza strains has the potential to vastly increase the diversity of circulating influenza viruses.
What role does viral reassortment play in flu pandemics?
Reassortment has been observed in members of all segmented virus families, including, for example, Bluetongue virus , but reassortment is most prominently described for influenza viruses as a primary mechanism for interspecies transmission and the emergence of pandemic virus strains [3–5].
What is the difference between reassortment and recombination in viruses?
Reassortment only occurs in segmented RNA viruses, whereas recombination stricto sensuoccurs in virtually all RNA viruses. The formation of a hybrid RNA sequence after inter-molecular exchange of genetic information between two nucleotide sequences results specifically from the latter.
What is reassortment?
Reassortment is the mixing of the genetic material of a species into new combinations in different individuals. Several different processes contribute to reassortment, including assortment of chromosomes, and chromosomal crossover.
What is recombination and how does it work?
Recombination is a pervasive process generating diversity in most viruses. It joins variants that arise independently within the same molecule, creating new opportunities for viruses to overcome selective pressures and to adapt to new environments and hosts.
How does recombination alter the codon state?
Interestingly, at the codon level, recombination can also alter the codon state by intra-codon recombination events (Arenas and Posada, 2010a), a process observed in viruses (Behura and Severson, 2013). Nevertheless, the fate of these genetic changes will be ultimately determined by natural selection and genetic drift.