CHINA PUBLISHES VIRUS GENOME

CHINA PUBLISHES VIRUS GENOME DATA

China has released genome sequencing data for the corona virus responsible for a recent outbreak in Beijing 

Details published on China ‘s National Microbiology Data Centre website revealed the Beijing genome data was based on three samples – two human and one environmental collected on June 11

According to preliminary genomic and epidemiological study results, the virus is from Europe, but it is different from the virus currently spreading in Europe 

Virus: Submicroscopic infectious agent that replicates only inside the living cells of an organism

Three main hypotheses explain the origins of viruses: Regressive hypothesis, viruses may have once been small cells that parasitised larger cells. Cellular origin hypothesis, some viruses may have evolved from bits of DNA or RNA that "escaped" from the genes of a larger organism. Co-evolution hypothesis, this is also called the 'virus-first hypothesis' and proposes that viruses may have evolved from complex molecules of protein and nucleic acid at the same time that cells first appeared on Earth and would have been dependent on cellular life for billions of years

Viruses display a wide diversity of shapes and sizes, called 'morphologies'

In general, viruses are much smaller than bacteria. Most viruses that have been studied have a diameter between 20 and 300 nanometres

 

A virus has either a DNA or an RNA genome and is called a DNA virus or an RNA virus, respectively. The vast majority of viruses have RNA genomes

In general, RNA viruses have smaller genome sizes than DNA viruses because of a higher error-rate when replicating, and have a maximum upper size limit

A viral genome, irrespective of nucleic acid type, is almost always either single-stranded or double-stranded

DNA viruses, genome replication of most DNA viruses takes place in the cell's nucleus.

RNA viruses, replication of RNA viruses usually takes place in the cytoplasm

Reverse transcribing viruses, reverse transcribing viruses with RNA genomes (retroviruses) use a DNA intermediate to replicate, whereas those with DNA genomes (pararetroviruses) use an RNA intermediate during genome replication

Recombination is common to both RNA and DNA viruses

Viral populations do not grow through cell division, because they are acellular. Instead, they use the machinery and metabolism of a host cell to produce multiple copies of themselves, and they assemble in the cell

Viruses can infect all types of life forms, from animals and plants to microorganisms, including bacteria and archaea

Viral infections in animals provoke an immune response that usually eliminates the infecting virus. Immune responses can also be produced by vaccines.