TOBACCO MOSAIC VIRUS (Genome organization &their replication) TMV is a plant virus which infects a wide range of plants, especially tobacco and other members of the family Solanaceae and cucumbers, and a number of ornamental flowers.
Animal viruses are self replicating, intracellular parasites that completely rely on host animal cell for reproduction. They use the host's cellular components to replicate, then leaves the host cell to infect other cells.
transformation in bacteria is a classical example of horizontal gene transfer which leads to enhanced survivability and also introduction of variations that may lead to evolution
INTRODUCTION:
The first plant virus shown to have a DNA genome and the first shown to replicate by reverse transcription.
Worldwide but only causes significantly losses locally.
It is transmitted by aphids .
Type member of the Caulimovirus genus, contains 11 species and 6 possible members.
significantly impact on plant virology and plant molecular biology.
The virus is an important source of gene regulatory elements, used exclusively in the genetic manipulation of plants.
STRUCTURE:Icosachedral with a diameter of 52Â nm built from 420 capsid protein subunits.
It contains a circular double-stranded DNA molecule of about 8.0 kB .
Dna is interrupted by sitespecific discontinuties resulting from its replication by reverse transcription.
After entering the host, the single stranded nicks in the viral DNA are repaired, forming a supercoiled molecule that binds to histones.
DNA is transcriped into a full length .
Replication
Risk Factors:The Cauliflower mosaic virus promoter (CaMV 35S) is used in most transgenic crops to activate foreign genes which have been artificially inserted into the host plant. It is inserted into transgenic plants in a form which is different from that found when it is present in its natural Brassica plant hosts. This enables it to operate in a wide range of host-organism environments which would otherwise not be possible.
TOBACCO MOSAIC VIRUS (Genome organization &their replication) TMV is a plant virus which infects a wide range of plants, especially tobacco and other members of the family Solanaceae and cucumbers, and a number of ornamental flowers.
Animal viruses are self replicating, intracellular parasites that completely rely on host animal cell for reproduction. They use the host's cellular components to replicate, then leaves the host cell to infect other cells.
transformation in bacteria is a classical example of horizontal gene transfer which leads to enhanced survivability and also introduction of variations that may lead to evolution
INTRODUCTION:
The first plant virus shown to have a DNA genome and the first shown to replicate by reverse transcription.
Worldwide but only causes significantly losses locally.
It is transmitted by aphids .
Type member of the Caulimovirus genus, contains 11 species and 6 possible members.
significantly impact on plant virology and plant molecular biology.
The virus is an important source of gene regulatory elements, used exclusively in the genetic manipulation of plants.
STRUCTURE:Icosachedral with a diameter of 52Â nm built from 420 capsid protein subunits.
It contains a circular double-stranded DNA molecule of about 8.0 kB .
Dna is interrupted by sitespecific discontinuties resulting from its replication by reverse transcription.
After entering the host, the single stranded nicks in the viral DNA are repaired, forming a supercoiled molecule that binds to histones.
DNA is transcriped into a full length .
Replication
Risk Factors:The Cauliflower mosaic virus promoter (CaMV 35S) is used in most transgenic crops to activate foreign genes which have been artificially inserted into the host plant. It is inserted into transgenic plants in a form which is different from that found when it is present in its natural Brassica plant hosts. This enables it to operate in a wide range of host-organism environments which would otherwise not be possible.
inroduction:Plant viruses are viruses that affect plants.
Pathogenic to higher plants.
. Harmless to human and other animals.
Reduce plant crop yield and quality of crops.
Some may be able to multiply within the bodies
Of aphids and nematodes.
History:Beijernick ( 1897) coined the latin name “VIRUS” meaning Poison. He studied plant juices and found they caused healthy plants to become sick.
Wendell Stanley (1935) crystallized sap from sick Tobacco plants. He discovered viruses were made of nucleic acids and proteins.
Geminivirus:one of the family of plant virus.
Currently over 360 species in this family, divided among 9 genera.
Diseases associated with this family include bright yellow mosaic , yellow mosaic, yellow mottle, leaf curling, stunting, streaks, reduced yields.
Ss circular dna diverge in both directions from a virion strand origin of replication (AMBISENSE).
Virus Classification:Group – Group II (ssDNA)
Order - Unassigned
Family - Geminiviridae
Genera – Becurtovirus Grablovirus
Begomovirus Mastrevirus
Capulavirus Topocuvirus
curtovirus Turncurtovirus
Eragrovirus
Structure: have Circular single-stranded DNA.
Genome is either in two segments.
The non-segmented genome is 2500-3000 nucleotides long, and the segmented genome is 4800-5600 nucleotides long.
The genome encodes for both structural and non-structural proteins.
In geminivirus, both segments must be transmitted to the host for a full systemic infection to occur.
Virion Sturcture:Geminivirus are non-enveloped, icosahedral virions that consists of a capsid.
The capsid is germinate, or twinned, and consists of 22 Capsomers.
The capsid is 30nm long and has a diameter of 18-20nm.
Symptoms:the time of infection, the virus strains and the presence of mixed infections.
Common symptoms are stunting, curling, and twisting of leaves.
Short internodes and stunted appearance , no apical growth caused by early infection.
Replication:Geminivirus encodes only a few proteins, thus they need to dependent host cell factors for replication.
These factors are DNA polymerase and repair polymerase to amplify their genome.
Replicate by a rolling circle mechanism like bacteriophages such as M13, and many plasmids.
CaMV Genome organization & their replication, Cauliflower Mosaic Virus belong to Group VII (ds-DNA-RT), Open circular double stranded DNA of 80kb and CaMV replicates by reverse transcription
inroduction:Plant viruses are viruses that affect plants.
Pathogenic to higher plants.
. Harmless to human and other animals.
Reduce plant crop yield and quality of crops.
Some may be able to multiply within the bodies
Of aphids and nematodes.
History:Beijernick ( 1897) coined the latin name “VIRUS” meaning Poison. He studied plant juices and found they caused healthy plants to become sick.
Wendell Stanley (1935) crystallized sap from sick Tobacco plants. He discovered viruses were made of nucleic acids and proteins.
Geminivirus:one of the family of plant virus.
Currently over 360 species in this family, divided among 9 genera.
Diseases associated with this family include bright yellow mosaic , yellow mosaic, yellow mottle, leaf curling, stunting, streaks, reduced yields.
Ss circular dna diverge in both directions from a virion strand origin of replication (AMBISENSE).
Virus Classification:Group – Group II (ssDNA)
Order - Unassigned
Family - Geminiviridae
Genera – Becurtovirus Grablovirus
Begomovirus Mastrevirus
Capulavirus Topocuvirus
curtovirus Turncurtovirus
Eragrovirus
Structure: have Circular single-stranded DNA.
Genome is either in two segments.
The non-segmented genome is 2500-3000 nucleotides long, and the segmented genome is 4800-5600 nucleotides long.
The genome encodes for both structural and non-structural proteins.
In geminivirus, both segments must be transmitted to the host for a full systemic infection to occur.
Virion Sturcture:Geminivirus are non-enveloped, icosahedral virions that consists of a capsid.
The capsid is germinate, or twinned, and consists of 22 Capsomers.
The capsid is 30nm long and has a diameter of 18-20nm.
Symptoms:the time of infection, the virus strains and the presence of mixed infections.
Common symptoms are stunting, curling, and twisting of leaves.
Short internodes and stunted appearance , no apical growth caused by early infection.
Replication:Geminivirus encodes only a few proteins, thus they need to dependent host cell factors for replication.
These factors are DNA polymerase and repair polymerase to amplify their genome.
Replicate by a rolling circle mechanism like bacteriophages such as M13, and many plasmids.
CaMV Genome organization & their replication, Cauliflower Mosaic Virus belong to Group VII (ds-DNA-RT), Open circular double stranded DNA of 80kb and CaMV replicates by reverse transcription
Viruses are microscopic organisms that exist almost everywhere on earth. They can infect animals, plants, fungi, and even bacteria.Viruses vary in complexity. They consist of genetic material, RNA or DNA, surrounded by a coat of protein, lipid (fat), or glycoprotein. Viruses cannot replicate without a host, so they are classified as parasitic.They are considered the most abundant biological entity on the planet.
Here we discuss the general properties of viruses in detail.
Structure and composition of plant virusesDivya Singh
Virus is chemically a nucleoprotein that multiplies only in the living cells and has ability to cause disease.
Nucleic acid may be RNA or DNA that is surrounded by a protective protein coat called capsid.
Plant viruses may be elongated, spherical and bacilliform in shape.
The nucleic acids RNA and DNA may be single stranded or double stranded.
Nucleic acid % is lower in elongated viruses where as spherical viruses contain higher % of nucleic acid.
Morphology, Classification, Cultivation and Replication of VirusKrutika Pardeshi
This presentation is Useful for B. Pharmacy SEM III Students to study the Topic Fungi According to PCI Syllabus.
It Consist of Morpholoy of Fungi, Cultivation , Replication and Classification of Virud
This is based on protein-ligand interaction physical method, which gives us knowledge about how our body protein interacts with other molecule and protein function.
The ability to recreate computational results with minimal effort and actionable metrics provides a solid foundation for scientific research and software development. When people can replicate an analysis at the touch of a button using open-source software, open data, and methods to assess and compare proposals, it significantly eases verification of results, engagement with a diverse range of contributors, and progress. However, we have yet to fully achieve this; there are still many sociotechnical frictions.
Inspired by David Donoho's vision, this talk aims to revisit the three crucial pillars of frictionless reproducibility (data sharing, code sharing, and competitive challenges) with the perspective of deep software variability.
Our observation is that multiple layers — hardware, operating systems, third-party libraries, software versions, input data, compile-time options, and parameters — are subject to variability that exacerbates frictions but is also essential for achieving robust, generalizable results and fostering innovation. I will first review the literature, providing evidence of how the complex variability interactions across these layers affect qualitative and quantitative software properties, thereby complicating the reproduction and replication of scientific studies in various fields.
I will then present some software engineering and AI techniques that can support the strategic exploration of variability spaces. These include the use of abstractions and models (e.g., feature models), sampling strategies (e.g., uniform, random), cost-effective measurements (e.g., incremental build of software configurations), and dimensionality reduction methods (e.g., transfer learning, feature selection, software debloating).
I will finally argue that deep variability is both the problem and solution of frictionless reproducibility, calling the software science community to develop new methods and tools to manage variability and foster reproducibility in software systems.
Exposé invité Journées Nationales du GDR GPL 2024
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
Nutraceutical market, scope and growth: Herbal drug technologyLokesh Patil
As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
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Richard's aventures in two entangled wonderlandsRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
Body fluids_tonicity_dehydration_hypovolemia_hypervolemia.pptx
Plant and animal viruse
1. A
SEMINAR
ON
PLANT AND ANIMAL VIRUSES
PROF. J.P. SHARMA (DIRECTOR)
DR. R.K. RAO (PRINCIPAL)
GUIDED BY - RACHANA TIWARI
PRESENTED BY..
NIKITA DEWANGAN
M.Sc.1st SEM
BIOTECHNOLOGY
G.D. RUNGTA COLLEGE OF SCIENCE & TECHNOLOGY
KOHKA-KURUD,BHILAI DURG (C.G.)
2. INTRODUCTION
HISTORY
MORPHOLOGY OF VIRUSES
PLANT VIRUS
TOBACCO MOSAIC VIRUS (TMV)
SYMPTOMS
VIRUS STRUCTURE
PROTEIN SYNTHESIS
TRANSMISSION
MODE OF ACTION
EFFECT OFVIRUS ON PLANT
ANIMAL VIRUS
CLASSIFICATION
DNA CONTAINING - SV 40 VIRUS
RNA CONTAINING - RHABDOVIRUS
CONCLUSION
REFRENCES
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3. INTRODUCTION
Viruses are small obligate intracellular parasites which by definition contain
either a RNA a or DNA genome , surrounded by a protective virus – coded
protein coat.
HISTORY
Edward Jenner (1798) introduced the term virus in microbiology.
Virus Greek means ‘’ poison’’.
In 1892 for the first time a Russian botanist DMITRI IWANOWSKI discover
the virus.
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4. SHAPE - Viruses are of different shapes such as spherical or cuboid ( adenovirus) ,
elongated (potato viruses), flexuous or coiled (beet yellow), bullet shaped (rabies
virus), filamentous ( bacteriophages M13) , pleomorphic.
SIZE - Variable size from 20 nm to 300 nm in diameter.
• They are smallest than bacteria, some are slightly larger than protein and nucleic
acid molecules and some are about of the same size ( small pox virus) as the
smallest bacterium and some virus slightly large (300 – 400 nm).
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5. 1. HELICAL ( CYLINDRICAL) VIRUSES -
The helical viruses are elongated, rod shaped, rigid or flexible.
There capsid is a hollow cylinder with a helical structure.
Capsid cosists of monomers arranged helically in rotational axis.
The consist may be naked e.g. TMV or envelope e.g. influenza virus.
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4Fig ; - 1 ,structure of helical virus
6. 2. POLYHEDRAL ( ICOSAHEDRAL)
VIRUSES -
Polyhedral structure has the three possible
symmetries such as tetrahedral, octahedral and
icosahedral.
The viruses are more or less spherical, therefore
icosahedral symmetry is the best one for
packaging and bonding of subunits.
The capsomers of each face form an equatorial
triangles and 12 intersepting point or corners.
They consist naked capsid e.g. adenovirus or
envelope e.g. herpes simplex virus.
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Fig ; 2 , structure of
polyhedral virus
7. 3. COMPLEX VIRUSES
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• The viruses which have
the unidentifiable
capsids or have the
capsids with additional
structures are called
complex viruses.
• Capsids not clearly
identified e.g. vaccinia
virus etc.
• Capsids to which some
other structure are
attached e.g. some
bacteriophages etc.
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Fig ; - 3 structure of complex virus
8. ENVELOPE -
• There are certain plant and animal viruses and bacteriophage both icosahedral and
helical , which are surrounded by a thin membranous envelope. This envelope is
about 10-15 µm thick . it us made up of protein , lipids and carbohydrates.
• Which are combined to form glycoprotein and lipoprotein.
• Lipids provide flexibility to the shape , therefore viruses look of variable size and
shape.
• Protein component of the envelope is of viral origin and lipid and carbohydrate may
be the feature of host membrane.
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9. • Plant viruses are viruses that affect plants like all other viruses plant
viruses are obligate intracellular parasites that do not have the molecular
machinery to replicate without a pathogenic to higher plants.
• Example ; - tobacco mosaic virus.
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10. INTRODUCTION
• TMV is the most serious pathogen causing mosaic on tobacco leaves.
• It is transmitted by artificial inoculation but not by insect vectors.
• TMV is the most resistant virus known so far of which the thermal death point is 90 ºc
for 10 minutes.
• This is the first virus that was crystallized in 1935 by W.M. STANLEY in the U.S.A.
SYMPTOMS
• TMV damages the salanaceous plants. However, it can infect theother plant too.
• After infection, it developes symptoms of lightning of leaf colour along the veins in early
stages.
• There after it turns into light and dark green mosaic symptoms.
• Along the veins green colour turns into dark green and the internal region turns into
chlorotic.
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11. • Some times dark green blisters appear in the leaf blade.
• The virus reduces the yield as well as quality of the products.
VIRUS STRUCTURE
• Franklin et al (1957) have described the structure of TMV.
• It is rod shaped helical virus measuring about 280µm with a molecular weight of
396 daltons.
• The virion is made up of 2130 protein subunit of identical size.
• The protein subunits are arranged around a central hole of 4nm (40 Å).
• Each protein subunit is made up of a single polypeptide chain which possesses
158 amino acids the molecular weight 17500 daltons.
• Inside the protein capsid there is a single stranded RNA molecule which is also
spirally coiled to form helix.
• Virus RNA consists of 6500 nucleotides.
• In one turn the RNA contain 49 nucleotides.
• Total numbers of protein subunit counting in three turns is 49.
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12. PROTEIN SYNTHESIS
• The virus RNA utilizes the amino acids ribosomes and tRNA of the host and
synthesizes the complementary strand and protein i.e. coat proteins of 17500daltons
and two other polypeptides.
• The ratio of nucleic acid and protein differs with each virus.
• Nucleic acid is about 5-40% of the virus and protein 60-70%.
• Each protein subunit of TMV consists of 158 amino acid making a total number to
about 17531.
TRANSMISSION
• TMV is transmitted through the cell sap of host and enters a new host through wound
incision.
• Wound is caused in plant due to various cultural operations such as clipping or
topping the shoot.
• It is also transmitted by wind and water.
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fig;4, structure of tobacco mosaic virus
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MODE OF ACTION
• In the cell the tobacco mosaic virus form crystals in the chloroplast and accumulate.
• Resulting pigment of cell which produces colour get affected, colour may turn to
colour less.
14. 1 . EXTERNAL SYMPTOMS :-
a. MOSAIC - Development of light (chlorosis) and dark green area on leaves are due
to disturbances of chloroplast and decrease in chlorophyll content.
b. CHLOROSIS , VEIN CLEARING AND VEIN BANDING - Vein clearing
symptoms develop adjacent to veins before chlorosis of tissue. While broader bands
of green tissue in chlorosis or necrosis is called vein banding.
c. RINGSPOT - Ringspot is characterized by formation of concentric rings or
broken rings of infected dead cells. The ringspot may be chlorotic rings rather than
necrotic rings.
d. NECROSIS - Besides localized cell death in necrotic local lesion or ringspots ,
necrosis in certain areas organs e.g. leaves, fruits, seeds , tubes or entire plant.
Affected leaves shows scattered necrotic patches of dead tissue.
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15. e. LEAF ABNORMALITIES - Due to virus infection leaves show abnormal growth
like leaf curling, leaf rolling, crinkling, puckering (depression)etc. the other
abnormalities may also develop in leaves such as smaller blistered and thickened
leaves.
f. FLOWER SYMPTOMS - The colour breaking means streaks or sector of tissue
with such colour that are different from the normal one. This happens due to loss or
increase of anthocyanin pigment in petals.
2. INTERNAL SYMPTOMS
a. HISTOLOGICALABNORMALITIES -
In leaves showing mosaic symptoms. Mesophyl cells are smaller and less
differentiated.
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16. b.CYTOLOGICALABNOMALITIES -
• Many cytological abnormalities are seen when virus infected cell are studied
cytologically. Moreover some viruses affect specific arganelles only.
• Tymovirus induces formation of marginal verticles in chloroplasts. Tobacco rattle
virus modifies mitochondria and aggregates to form inclusion bodies.
• TMV particles are found in cytoplasm where as TMV of strain U5 are round in
chloroplasdt and nuclei.
• Chloroplasts may be rounded swollen and clumped together in the cells . chloroplast
may be fragmented and colour may turn to colour less.
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17. CLASSIFICATION - On the basis of types of nucleic acid the classification of
viruses are as :-
Class 1. dsDNA viruses
• Adenoviruses genome size 35-40 kb.
• Herpes virus genome size 120- 200 kb.
• Papovavirus genome size 5-8 kb.
• Pox virus genome size 120-300 kb.
Class 2. ssDNA viruses
• Parvovirus genome size 4-5kb.
Class 3. (+) ss RNA viruses
• Coranavirus genome size 16-21 kb.
• Picorna virus genome size 7 kb.
• Togavirus genome size 17 kb.
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18. Class 4. (-) ssRNA viruses
• Paramyxoviruses genome size 15 kb.
• Rhabdovirus genome size 12- 1 kb.
• Orthomyxovirus genome size 14 kb.
Class 5. dsRNA viruses
• Reovirus genome size 18-30 kb.
Class 6. RNA – DNA viruses
• In these viruses (+) ssRNA direct synthesia of (-) DNA which in turn acts as template
for the transcription of mRNA .
• Retrovirus genome 7-10 kb.
Class 7. DNA- RNA viruses
• This group consists of DNA containing hepatitis B viruses.
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19. The DNA containing animal virus : - SV40 virus
• SV40 is an oncogenic virus.
• It is naked and icosahedral in morphology with a diameter of 45nm.
• Capsid consists of 72 capsomeres.
• SV40 is similar to polyoma virus in size and structure.
• Polyoma is associated with tumour in mice.
REPLICATION
• Virus enters the cell and directly migrats to the nucleus and then mutation cause in
genetic material of host resulting normal activity of cell inhibit which causes tumor.
• Replication of viral RNA takes place inside the nucleus.
• Before the replication begins early proteins are synthesized in the nucleus of the
infected cells.
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20. • The ds- DNA in its native form is supercoiled ( i.e. covalently closed circle ) . helix
having the sedimentation coefficient of 215.
• Total G+C content of acid is 41%.
• After breaking the phosphodiester bond single stranded DNA helix is converted into a
relaxed circular form.
• This form has the sedimentation coefficient of 165. A linear form ( of 145) is formed
after double stranded break in the supercoil.
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Fig ; 5, SV40 virus structure
21. The RNA containing virus :- Rhabdovirus
• Rhabdovirus are bullet shaped with one flattened end.
• Rhabdo is a Greek word which means a rod but the term rod is not accurate to its
morphology.
• Rhabdoviruses are found in vertebrates, invertebrates and plant.
• The example of rhabdovirus are rabies virus, vesicular stromatitis virus (VSV) and potato
yellow dwaef virus.
• VSV is the most extensively studied rhabdovirus.
• It is a mild pathogen to cattle. . Vesicular stromatitis virus affect the central nervous
system so host parasite do abnormal behavior.
• VSV contain a nucleocapsid (70 – 180) which is envelope on its outer surface, consists of
numerous spikes of glycoprotein on inner surface and the membrane (M) protain.
PLANT AND ANIMAL VIRUS
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A
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M
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L
V
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R
U
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22. PLANT AND ANIMAL VIRUS
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Fig; 6, structure of Rhabdovirus
• Inside the nucleocapsid, there is a (-) ssRNA molecule which is cylindrically coiled to
make the core hollow.
• The RNA polymerase uses (-) RNA strand as the template and produce (+) RNA strand.
• The (+) RNA strand acts as mRNA and as a template for the synthesis of viral RNA.
23. • It is concluded that a virus is a non- cellualar particle made up to genetic
material and protein that can invade living cell.
• Virus can replicate its genetic material in the host cell.
• Virus can naked as well as have envelope.
• Virus can infect all type of life – animal , plant , human and cause diseases.
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O
N
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I
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24. R. C. DUBEY 2006 MICROBIOLOGY
SOME CONTENT FROM NET : -
www.ncbi.nlm.nih.gov/books/NBK8174/virus
PLANT AND ANIMAL VIRUS
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E
F
R
E
N
C
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S