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Basic knowledge of coronavirus subfamily

Update:25-11-2021
Summary:

Coronavirus subfamily (scientific name: Orthocoronaviri […]

Coronavirus subfamily (scientific name: Orthocoronavirinae), commonly known as Coronavirus (English: Coronavirus), is a type of zoonotic single-stranded RNA virus that spreads between animals and humans. Coronavirus can infect mammals and birds, causing digestive tract diseases in cattle and pigs or upper respiratory tract diseases in chickens. Common in nature, there are seven types of coronaviruses that are known to infect humans. They can cause respiratory infections in humans, causing common colds, and even Middle East Respiratory Syndrome (MERS), Severe Acute Respiratory Syndrome (SARS) and 2019 Coronavirus Disease (COVID-19) and other more serious diseases.

Coronavirus subfamily belongs to the Reticulovirus order Coronavirus suborder Coronavirus family, which is further divided into four genera: α, β, γ, and δ. The genome size of the coronavirus is between 26,000 and 32,000 base pairs, making it the largest type of RNA virus with the genome size. Coronavirus is spherical or elliptical under an electron microscope, with regularly arranged cystic collagen fiber protrusions, which resemble a crown shape, hence the name. The viral envelope is composed of a double layer of lipids, interspersed with membrane proteins and spike proteins, and some also contain hemagglutinin. Inside the virus is a nucleoprotein core composed of RNA and capsid protein, which has a helical structure.

history

Coronavirus was first discovered in 1960. The first was the avian infectious bronchitis virus (IBV) found in poultry. Later, two cases were detected in the nasal cavity of humans suffering from the common cold, named human coronavirus 229E and human coronavirus OC43.

The members of the coronavirus also include the 2003 Severe Acute Respiratory Syndrome, also known as atypical pneumonia or SARS. Human Coronavirus NL63 in 2004. Human Coronavirus HKU1 in 2005. Middle East Respiratory Syndrome coronavirus discovered in 2012. The 2019 new coronavirus discovered in 2019. Most of the above viruses can cause severe respiratory infections.

way for spreading

After the virus enters the human cell, the virus removes the outer shell and releases the ribonucleic acid (RNA) genome into the cytoplasm. The RNA genome of the coronavirus has a 5'methylated end cap and a 3'polyadenylated tail. This allows it to attach to human ribosomes for translation.

The source of the coronavirus can be traced back to 8000 BC at the latest. It may also be 8100 BC. Non-cold-blooded flying animals, bats and birds seem to be the best hosts for coronaviruses (bats carry A and B coronaviruses; birds carry C and D coronaviruses). The domestic animal coronavirus and the dog respiratory coronavirus came from a common ancestor in 1951. Livestock coronavirus and human coronavirus OC43 began to evolve independently in 1899. The livestock coronavirus was isolated from the equine coronavirus in the 18th century. It is also possible that the human coronavirus OC43 was isolated from livestock coronavirus in 1890. The most recent common ancestor of the human coronavirus OC43 has been traced back to the 1950s.
The coronavirus deposited in bats and the SARS virus that causes severe acute respiratory syndrome began to diverge in 1986. The SARS virus has been pointed out to be closely related to bats. Researchers have shown that the coronavirus and bats have undergone a long-term co-evolution. The SARS virus was first carried by the old world leaf-nosed bats, and then infected to chrysanthemum bats, then to civet cats, and finally To humans.

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