Gammacoronavirus
Gammacoronavirus is a genus of coronaviruses within the Coronaviridae family, characterized as enveloped and single-stranded RNA viruses. These viruses are known for their spike-like projections that give them a crown-like appearance, which is reflected in their name, as "corona" means "crown" in Latin. Gammacoronaviruses primarily infect birds, although they can also affect some mammal species. One notable species is the Infectious bronchitis virus (IBV), which is a significant pathogen in poultry, particularly chickens, causing respiratory disease and substantial economic losses in the poultry industry. Another species, Turkey coronavirus (TCoV), infects turkeys and can lead to severe intestinal disease, particularly in younger birds. While vaccines have been developed for IBV, their efficacy can vary due to different virus strains; currently, there are no effective vaccines for TCoV. Additionally, gammacoronaviruses have been discovered in marine mammals, such as the BWCoV-SW1 in beluga whales and BdCoVs in dolphins, with both causing intestinal disease. Overall, gammacoronaviruses have a long history of affecting various animal populations, with some species dating back to around 2800 BCE.
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Gammacoronavirus
Gammacoronavirus is one of four genera, or types, of coronaviruses, which are members of the family Coronaviridae. These viruses are enveloped and single-stranded, positive-stranded RNA viruses. Coronaviruses, including those in the gammacoronavirus genus, have spike-like projections that cover their surfaces. The protein spikes resemble crown-like patterns, which gives the virus its name. In Latin, corona means “crown.” Coronaviruses infect vertebrates, including mammals and birds. Two genera, alphacoronaviruses and betacoronaviruses, can infect humans, but by the early 2020s scientists had not found any gammacoronavirus species that infect humans. Gammacoronavirus is also the smallest genus of coronaviruses in terms of the number of identified species. Scientists estimate that first gammacoronavirus species developed in about 2800 BCE. Scientists identified the first diseases caused by gammacoronaviruses in the 1930s, when they noted an outbreak of infectious bronchitis in poultry caused by these viruses.
Overview
Different species of gammacoronaviruses infect different animals. They most commonly infect birds, but they can also infect a limited number of mammals. Infectious bronchitis virus (IBV) is a species of gammacoronavirus that infects chickens. This virus causes avian IBV, which is a serious respiratory disease. Research has shown that different breeds of chickens are affected differently by the virus, with some types contracting less severe disease and other contracting more severe cases. Research also indicates that other types of birds, such as quail and gulls, can be infected with IBV. IBV is a leading cause of economic loss in poultry production, as both meat-producing and egg-producing birds can die from the virus. Scientists have developed vaccines to protect poultry against the virus, but different strains of the virus have made these vaccines less effective. This virus replicates not only in birds’ respiratory tracts but also in their gastrointestinal tracts.
Turkey coronavirus (TCoV) is another gammacoronavirus that affect avian species. TCoV most commonly infects turkeys and causes intestinal disease in the birds that can be deadly. Young turkeys are more susceptible to the disease than older turkeys. Younger birds also shed more virus when they are infected than older birds. Scientists have not yet developed an effective vaccine for TCoV, and it remains one of the viruses that causes the most economic loss in the commercial turkey industry. Scientists have sequenced the TCoV genome.
Both the gammacoronavirus and alphacoronavirus genera have also been found to infect marine mammals. BWCoV-SW1 is a gammacoronavirus that seemingly infects whales. It was first identified in a deceased beluga whale that lived in captivity. Scientists identified the virus in liver tissue. The disease caused by the virus was named beluga whale CoV. In 2019, scientists identified BdCoVs in dolphins living in captivity in the United States. The virus seemed to cause intestinal disease, with infected animals having diarrhea. Scientists believe that these two gammacoronavirus are closely related. Scientists sequenced the genomes of the viruses and found that, of the identified coronaviruses, those two had the longest genomes identified up to that point.
Bibliography
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