Coronaviruses are a group of viruses that cause respiratory illness in humans and other animals. COVID-19 is an infectious disease caused by the SARS-CoV-2 coronavirus. Common symptoms include fever, cough, and shortness of breath. While most cases result in mild symptoms, some can lead to pneumonia or multiple organ failure. The virus spreads primarily through respiratory droplets when people are in close contact. There is no vaccine yet, so prevention focuses on hand washing, social distancing, and isolation for those who may be infected. Identification of new coronaviruses can be done using cDNA-AFLP, which allows expression analysis without prior genome sequence knowledge.

1. REVIEW ON
CORONAVIRUS
AJAY SAMUEL.S
III UG BIOTECHNOLOGY
RATHNAVEL SUBRAMANIYAM COLLEGE OF ARTS AND SCIENCE,SULUR COIMBATORE.

2. WHAT IS A CORONA VIRUS
 Corona virus are group of viruses which cause respiratory disease in mammals
and amphibians
 In humans it cause common cold in mild cases and can be lethal like SARS,
MERS and COVID-19.
 CORONAVIRUS comes from a subfamily orthocoronavirinae, family called
coronaviridae.
 It comes under order of NIDOVIRALES, and realm RIBOVIRIA.

3. Continued……
 They are enveloped viruses with a positive-sense single-
stranded RNA genome and a nucleocapsid of helical symmetry. The genome
size of coronaviruses ranges from approximately 27 to 34 kilobases, the
largest among known RNA viruses.
 The name coronavirus is derived from the Latin corona, meaning "crown" or
"halo", which refers to the characteristic appearance reminiscent of a crown
or a solar corona around the virions (virus particles) when viewed under two-
dimensional transmission electron microscopy, due to the surface covering in
club-shaped protein spikes.

4. Coronavirus molecule

5. Corona virion

6. Identification of coronavirus
 The subsequent method of identification method may fail because of the non
replicative property of virus invitro. Though in some viral diagnostics invitro
results in cytopathic effect .
 Antibiotics may be effective on known virion on screening process of culture
viruses, but not effective on unknown virions.
 Under such complications new method is been used to identify the new virion
called cDNA-amplified restriction fragment-length polymorphism technique.

7. cDNA-AFLP(Marnik Vuylstekeet al 31may
2017)
 Although DNA microarrays are currently the standard tool for genome-wide
expression analysis, their application is limited to organisms for which the
complete genome sequence or large collections of known transcript
sequences are available.
 Though cDNA-AFLP, an AFLP-based transcript profiling method that allows
genome-wide expression analysis in any species without the need for prior
sequence knowledge.
 In essence, the cDNA-AFLP method involves reverse transcription of mRNA
into double-stranded cDNA, followed by restriction digestion, ligation of
specific adapters and fractionation of this mixture of cDNA fragments into
smaller subsets by selective PCR amplification

8. Continued…
 The resulting cDNA-AFLP fragments are separated on high-resolution gels, and
visualization of cDNA-AFLP fingerprints is described using either a
conventional autoradiography platform or an automated LI-COR system.
Observed differences in band intensities between samples provide a good
measure of the relative differences in the gene expression levels.
Identification of differentially expressed genes can be accomplished by
purifying cDNA-AFLP fragments from sequence gels and subsequent
sequencing.
 This method has found widespread use as an attractive technology for gene
discovery on the basis of fragment detection and for temporal quantitative
gene expression analysis.

9. COVID-19
 Corona Virus Disease 2019 is an infectious disease caused by severe acute
respiratory syndrome corona virus 2(SARS-coV-2)
 This disease was first identified in Wuhan, central china. It results in a 19-20
pandemic .
 Common symptoms are fever, cough, and shortness of breath. Muscle
pain, sputum production, diarrhea, and sore throat are mild symptoms and in
severe cases pneumonia and organs failure.
 The virus is typically spread from one person to another via respiratory
droplets produced during coughing. Primarily, it spreads when people are in
close contact but it may also spread when one touches a contaminated
surface and then their face. It is most contagious when people are
symptomatic, although spread may be possible before symptoms appear.

10.  The time between exposure and symptom onset is typically around five days,
but may range from two to fourteen days. Common symptoms
include fever, cough, and shortness of breath. Complications may
include pneumonia and acute respiratory distress syndrome. There is
no vaccine or specific antiviral treatment. Primary treatment
is symptomatic and supportive therapy. Recommended preventive measures
include hand washing, covering the mouth when coughing, maintaining
distance from other people, and monitoring and self-isolation for people who
suspect they are infected.
 Source : google /wikipedia.org/wiki/2019–20_coronavirus_pandemic

11. Prevention
1. Cover when cough and sneeze with a sterile tissue,
then discard it properly in the trash.
2. Avoid close contact with people who are sick.
3. Avoid touching your eyes, nose and mouth.
4. Clean and disinfect frequently touched object and
surfaces.
5. Stay isolated when you are sick and get a medical
attention when having symptoms of COVID19.
6. Wash your hands with soap and water frequently, for
aleast 20 seconds.

12. REFERENCE
Published: 21 March 2004 Identification of a new human coronavirus Lia van
der Hoek et al.
 Wikipedia
 Google scholar(Kathryn V. Holmes may 15, 2003 The New England Journal of
Medicine
 https://en.wikipedia.org/wiki/2019%E2%80%9320_coronavirus_pandemic
 www.cdc.gov/COVID19.