![]() ![]() L., Camero, M., Manna, L., D’Aloja, D., & Buonavoglia, C. ĭecaro, N., Martella, V., Desario, C., Bellacicco, A. The placenta goes viral: Retroviruses control gene expression in pregnancy. Epidemic dynamics and antigenic evolution in a single season of influenza A. Methods in Molecular Biology (Clifton, N.J.), 655, 27–45. Virus-induced gene silencing as a reverse genetics tool to study gene function. īernacki, S., Karimi, M., Hilson, P., & Robertson, N. The route of HIV escape from immune response targeting multiple sites is determined by the cost-benefit tradeoff of escape mutations. This article covers briefly the evolution of viruses in terms of genetic variation.īatorsky, R., Sergeev, R. There are two different forms of genetic changes: antigenic drift and antigenic shift. The high mutation rates of RNA viruses, which are the result of an error-prone RNA-dependent RNA polymerase, make them a veritable gold mine for researchers interested in discovering evolutionary novelty and developing new methods to study evolution in action. Additionally, because viruses often make several copies in an infected host, altered genes can be rapidly transmitted to a large number of offspring. ![]() ![]() The rapid pace of viral mutation paired with natural selection enables viruses to rapidly adapt to changes in the host environment, despite the fact that the majority of viral mutations offer little benefit and frequently prove to be harmful. Many viruses, especially RNA viruses, have relatively high mutation rates and short production durations (on the order of one point mutation or more per genome per round of replication). ![]() Viral evolution is a subdiscipline of evolutionary biology and virology that focuses on the evolution of viruses. It also has been suspected to occur in some cancer-causing viruses in humans.Tarumanagara University, Jakarta, IndonesiaĮvolution Virus antigenic shift antigenic drift Genetics Abstract Usually responsible for epidemics in between pandemics.Įxample: The 1968 pandemic arose when the H3 hemagglutinin gene and one other internal gene from an avian donor reassorted with the N2 neuraminidase and five other genes from the H2N2 human strain that had been in circulation.Įxample: The 1918 pandemic arose when an avian H1N1 strain mutated to enable its rapid and efficient transfer from human-to-human.Įxample: The subtle mutations accumulated through antigenic drift of these subtypes (e.g., H1N1, H3N2, H5N1) give rise to different strains of each subtype.Įxample: Antigenic drift is also known to occur in HIV (human immunodeficiency virus), which causes AIDS, and in certain rhinoviruses, which cause common colds in humans. Give rise to pandemics, which occurs irregularly and unpredictably. Occurs as a result of the accumulation of point mutations in the gene.Īn antigenic change which results in drastic or dramatic alternation in HA (hemagglutinin) or NA (neuraminidase) subtypes.Īn antigenic change can alter antigenic sites on the molecule such that a virion can escape recognition by the host’s immune system.Įasy to treat (antibody and drugs available) Occurs as a results of genome reassortment between difference subtypes. May jump from one species to another (animal-human) Some of the Differences Between Antigenic Shift and Antigenic Drift are as follows: S.N.įorming new sub-type (Subtype A + Subtype B –> New Subtype) They are Antigenic Shift and Antigenic Drift. The two surface antigens of influenza undergo antigenic variation independent of each other. Influenza Virus are remarkable because of the frequent antigenic change that occurs in HA (hemagglutinin) or NA (neuraminidase). ![]()
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