''Beluga whale coronavirus SW1'' (Whale-CoV SW1) is a mammalian ''

Gammacoronavirus ''Gammacoronavirus'' (Gamma-CoV) is one of the four genera (''Alpha''-, '' Beta-'', ''Gamma-'', and '' Delta-'') of coronaviruses. It is in the subfamily ''Orthocoronavirinae'' of the family ''Coronaviridae''. They are enveloped, positive-sens ...

'', an

RNA virus An RNA virus is a virusother than a retrovirusthat has ribonucleic acid (RNA) as its genetic material. The nucleic acid is usually single-stranded RNA ( ssRNA) but it may be double-stranded (dsRNA). Notable human diseases caused by RNA viruses ...

, discovered through genome sequencing in the

liver The liver is a major Organ (anatomy), organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the Protein biosynthesis, synthesis of proteins and biochemicals necessary for ...

of a single deceased

beluga whale The beluga whale () (''Delphinapterus leucas'') is an Arctic and sub-Arctic cetacean. It is one of two members of the family Monodontidae, along with the narwhal, and the only member of the genus ''Delphinapterus''. It is also known as the whi ...

and first described in 2008. This was the first description of the complete

genome In the fields of molecular biology and genetics, a genome is all the genetic information of an organism. It consists of nucleotide sequences of DNA (or RNA in RNA viruses). The nuclear genome includes protein-coding genes and non-coding ge ...

of a

coronavirus Coronaviruses are a group of related RNA viruses that cause diseases in mammals and birds. In humans and birds, they cause respiratory tract infections that can range from mild to lethal. Mild illnesses in humans include some cases of the com ...

found in a marine mammal. The captive-born whale was male and died at age 13 after a short illness. This illness was characterised by generalised pulmonary disease and terminal acute liver failure. The liver demonstrated pathological signs, including areas of

necrosis Necrosis () is a form of cell injury which results in the premature death of cells in living tissue by autolysis. Necrosis is caused by factors external to the cell or tissue, such as infection, or trauma which result in the unregulated dige ...

Electron microscopy An electron microscope is a microscope that uses a beam of accelerated electrons as a source of illumination. As the wavelength of an electron can be up to 100,000 times shorter than that of visible light photons, electron microscopes have a hi ...

showed many round viral particles measuring around 60–80nm in the liver

cytoplasm In cell biology, the cytoplasm is all of the material within a eukaryotic cell, enclosed by the cell membrane, except for the cell nucleus. The material inside the nucleus and contained within the nuclear membrane is termed the nucleoplasm. The ...

, but it could not be confirmed whether these corresponded with the RNA identified. It is not known whether the beluga is the natural host of this virus or whether the virus is pathogenic in whales. Other coronaviruses can cause liver pathologies, but it could not be confirmed whether that was the case here. A genetic analysis showed the virus to be highly divergent, but closest to the ''Gammacoronavirus'' group. A closely related virus was subsequently reported in

bottlenose dolphin Bottlenose dolphins are aquatic mammals in the genus ''Tursiops.'' They are common, cosmopolitan members of the family Delphinidae, the family of oceanic dolphins. Molecular studies show the genus definitively contains two species: the common ...

s, with the authors proposing that both should be included in the same species, ''Cetacean coronavirus''.

References

{{Taxonbar, from= Q18965336, from2= Q57754725 Gammacoronaviruses Animal viral diseases Cetacean diseases

See also

References