This document is a report submitted by a student on the topic of Mu phage. It includes:
1) An overview of Mu phage, including that it is a bacteriophage that infects enterobacteria and can cause transposition of genes.
2) A description of the structure of Mu phage including its icosahedral head, neck, and contractile tail.
3) Details on the genetic map of Mu phage, including that it has a 37,611 base pair genome that encodes 55 genes with various functions.
4) An explanation of the life cycle of Mu phage from attachment to host cell to replication of the viral genome and cell lysis.
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
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
A bacteriophage (informally, phage) is a virus that infects and replicates within a bacterium. The term is derived from "bacteria" and the Greek (phagein), "to devour". Bacteriophages are composed of proteins that encapsulate a DNA or RNA genome, and may have relatively simple or elaborate structures. Their genomes may encode as few as four genes, and as many as hundreds of genes. Phages replicate within the bacterium following the injection of their genome into its cytoplasm. Bacteriophages are among the most common and diverse entities in the biosphere.
Phages are widely distributed in locations populated by bacterial hosts, such as soil or the intestines of animals. One of the densest natural sources for phages and other viruses is sea water, where up to 9×108 virions per milliliter have been found in microbial mats at the surface,] and up to 70% of marine bacteria may be infected by phages. They have been used for over 90 years as an alternative to antibiotics in the former Soviet Union and Central Europe, as well as in France. They are seen as a possible therapy against multi-drug-resistant strains of many bacteria (see phage therapy). Nevertheless, phages of Inoviridae have been shown to complicate biofilms involved in pneumonia and cystic fibrosis, shelter the bacteria from drugs meant to eradicate disease and promote persistent infection
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.
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.
Viruses are small, acellular particles that can replicate only in a host cell. They are obligatory intracellular parasites.They
consist of a nucleic acid genome enclosed in a protective protein shell or capsidBacteriophage is the virus that infect bacteria.Bacteriophages were discovered by Frederick Twort(1915)and Felix d'Herelle(1917).
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.
A bacteriophage (informally, phage) is a virus that infects and replicates within a bacterium. The term is derived from "bacteria" and the Greek (phagein), "to devour". Bacteriophages are composed of proteins that encapsulate a DNA or RNA genome, and may have relatively simple or elaborate structures. Their genomes may encode as few as four genes, and as many as hundreds of genes. Phages replicate within the bacterium following the injection of their genome into its cytoplasm. Bacteriophages are among the most common and diverse entities in the biosphere.
Phages are widely distributed in locations populated by bacterial hosts, such as soil or the intestines of animals. One of the densest natural sources for phages and other viruses is sea water, where up to 9×108 virions per milliliter have been found in microbial mats at the surface,] and up to 70% of marine bacteria may be infected by phages. They have been used for over 90 years as an alternative to antibiotics in the former Soviet Union and Central Europe, as well as in France. They are seen as a possible therapy against multi-drug-resistant strains of many bacteria (see phage therapy). Nevertheless, phages of Inoviridae have been shown to complicate biofilms involved in pneumonia and cystic fibrosis, shelter the bacteria from drugs meant to eradicate disease and promote persistent infection
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.
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.
Viruses are small, acellular particles that can replicate only in a host cell. They are obligatory intracellular parasites.They
consist of a nucleic acid genome enclosed in a protective protein shell or capsidBacteriophage is the virus that infect bacteria.Bacteriophages were discovered by Frederick Twort(1915)and Felix d'Herelle(1917).
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.
Eng.Abdulrahman Mohamud Dirie
Education
BSc in Marine and Environmental Science from Hudeida University in Yemen 2014.
MSc in Water policy from Pan African university institute of water and energy science inc. climate change – PAUWES.
Work
Executive Director of Somalia Water Partnership (SWP)
Head of Marine Biotic Resources at Somali Marine Resource Research Center (SMRRC).
He is a senior lecturer at Somalia Marine Academy and former senior lecturer at Benadir University and Darul Hikma University.
Bacteriophage (phage) are obligate intracellular viruses that specifically infect bacteria and just like other viruses and need a host cell to reproduce.
They may transmit genetic information from bacterium to another by the process named transduction.
The most studied group is that of tailed phages with a dsDNA genome, and it also represents the largest group . The tailed phages have three major components:
a capsid where the genome is packed,
a tail that serves as a pipe during infection to secure transfer of genome into host cell and
a special adhesive system (adsorption apparatus) at the very end of the tail that will recognize the host cell and penetrate its wall.
Hello everyone, I am Dr. Ujwalkumar Trivedi, Head of Biotechnology Department at Marwadi University Rajkot. I teach Molecular Biology to the students of M.Sc. Microbiology and Biotechnology.
The current presentation talks about replication and partition mechanism of plasmid. The later part of the presentation describes "Theta Model" and "Rolling Circle Model" of replication.
Richard's entangled aventures in wonderlandRichard 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.
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
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.
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.
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.
Introduction:
RNA interference (RNAi) or Post-Transcriptional Gene Silencing (PTGS) is an important biological process for modulating eukaryotic gene expression.
It is highly conserved process of posttranscriptional gene silencing by which double stranded RNA (dsRNA) causes sequence-specific degradation of mRNA sequences.
dsRNA-induced gene silencing (RNAi) is reported in a wide range of eukaryotes ranging from worms, insects, mammals and plants.
This process mediates resistance to both endogenous parasitic and exogenous pathogenic nucleic acids, and regulates the expression of protein-coding genes.
What are small ncRNAs?
micro RNA (miRNA)
short interfering RNA (siRNA)
Properties of small non-coding RNA:
Involved in silencing mRNA transcripts.
Called “small” because they are usually only about 21-24 nucleotides long.
Synthesized by first cutting up longer precursor sequences (like the 61nt one that Lee discovered).
Silence an mRNA by base pairing with some sequence on the mRNA.
Discovery of siRNA?
The first small RNA:
In 1993 Rosalind Lee (Victor Ambros lab) was studying a non- coding gene in C. elegans, lin-4, that was involved in silencing of another gene, lin-14, at the appropriate time in the
development of the worm C. elegans.
Two small transcripts of lin-4 (22nt and 61nt) were found to be complementary to a sequence in the 3' UTR of lin-14.
Because lin-4 encoded no protein, she deduced that it must be these transcripts that are causing the silencing by RNA-RNA interactions.
Types of RNAi ( non coding RNA)
MiRNA
Length (23-25 nt)
Trans acting
Binds with target MRNA in mismatch
Translation inhibition
Si RNA
Length 21 nt.
Cis acting
Bind with target Mrna in perfect complementary sequence
Piwi-RNA
Length ; 25 to 36 nt.
Expressed in Germ Cells
Regulates trnasposomes activity
MECHANISM OF RNAI:
First the double-stranded RNA teams up with a protein complex named Dicer, which cuts the long RNA into short pieces.
Then another protein complex called RISC (RNA-induced silencing complex) discards one of the two RNA strands.
The RISC-docked, single-stranded RNA then pairs with the homologous mRNA and destroys it.
THE RISC COMPLEX:
RISC is large(>500kD) RNA multi- protein Binding complex which triggers MRNA degradation in response to MRNA
Unwinding of double stranded Si RNA by ATP independent Helicase
Active component of RISC is Ago proteins( ENDONUCLEASE) which cleave target MRNA.
DICER: endonuclease (RNase Family III)
Argonaute: Central Component of the RNA-Induced Silencing Complex (RISC)
One strand of the dsRNA produced by Dicer is retained in the RISC complex in association with Argonaute
ARGONAUTE PROTEIN :
1.PAZ(PIWI/Argonaute/ Zwille)- Recognition of target MRNA
2.PIWI (p-element induced wimpy Testis)- breaks Phosphodiester bond of mRNA.)RNAse H activity.
MiRNA:
The Double-stranded RNAs are naturally produced in eukaryotic cells during development, and they have a key role in regulating gene expression .
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
Thanks...!
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.
1. Sri paramakalyani college
Alwarkurichi 627 412
COURSE TITLE: virology
COURSE WORK TITLE: MU phage
Submitted to,
GUIDE: Dr.C.MARIAPPAN, Ph.D,
ASSISTANT PROFESSOR,
SRI PARAMAKALYANI COLLEGE,
ALWARKURICHI.
Submitted by
Student name : S. Azhagammal
Register number : 20211232526107
Class : I M. Sc Microbiology
Date of Submission :
2. Synopsis
Mu phage
Structrue of mu phage
Genetic map of mu phage
The functions of different genes are as follows
Life Cycle of Mu Phage
Reference
3. MU phage
◦Phage Mu is also known as bacteriophage Mu.
◦Since it infects the members of enterobacteria, it is
also called enterobacteria phage Mu.
◦It belongs to the family Myoviridae and dsDNA
viruses.
◦Mu phage is alsocalled temperate or transposable
phage because it causes transposition of the genes
into the host cell, at the time of multiplication.
4. ◦Bacteriophage Mu, also known as mu
phage or mu bacteriophage, is a muvirus (the
first of its kind to be identified) of the
family Myoviridae which has been shown to cause
genetic transposition.
◦It is of particular importance as its discovery
in Escherichia coli by Larry Taylor was among
the first observations of insertion elements in a
genome.
5.
6. Structure of Mu Phage
◦As we know the basic structure of the bacteriophage,
that is comprised of head, neck and tail.
◦The structure of Mu phage is also divided into three
parts i.e. head neck and tail
◦Head : It is the terminal part of the Mu phage which
carries the viral genome and surrounds by a protein
layer refers as Capsid.
◦The head of Mu phage is having icosahedral
symmetry.
7. ◦The shape is like spheroid.
◦The diameter is 54 nm.
◦Capsid is the layer which surrounds the hexagonal
head.
◦The capsid of Mu phage is composed of about 152
smaller protein subunits, known as “Capsomeres”
◦Neck: It is the middle portion of the Mu phage, acts
as the joining element which joins the two
components i.e. Head and tail.
8. ◦Tail : It is long, thick and contractile because of the
presence of cross bands.
◦The size of the tail is 183 X 16-20nm.
◦Sheath is the covering of the contractile tail, which
is composed of stacked rings.
◦At the time of contraction, the sheath becomes
shorter and thicker.
◦And the length of the sheath during contraction is up
to 60-90nm.
◦Tails fibers are thin and thread-like structures which
are attached to the large base plate.
◦There are six long terminal fibres.
9. Genetic map of Mu Phage
◦Mu phage consists of a ds-DNA which is linear,
◦The genome of Mu phage consists of 37,611 base
pairs.
◦The guanine and cytosine content is 35%.
◦Genome consists of some unusual base
pairs(hydroxy methyl uracil) and terminally
redundant sequences.
◦Mu phage genome encodes 55 genes which perform
different functions in its life cycle.
11. The functions of different genes are as
follows:
◦Mu-phage consists of two transposase binding sites that
bind to the host DNA and represented as attL and attR.
These two ends sometimes called as MuL and MuR.
◦A gene: It encodes all transposition events.
◦B gene: It encodes the all replicative transposition.
◦C gene: It represses the expression of the transposase gene.
◦Head and tail genes: These are the structural genes that
help in reconstruction or biosynthesis of Mu phage.
◦Gin gene: It catalyzes the site-specific inversion reactions.
12. ◦Mom gene: It encodes a DNA modification function by
converting adenine to acetamide adenine.
◦Lye gene: It encodes the lytic enzyme, which causes lysis
of the host cell.
13. Life Cycle of Mu Phage
Its lifecycle can be summarized in the following steps:
Attachment : Firstly, the tail fibres attach to the receptor site of
the host cell surface. By the binding of the tail fibre, there is the
conformational change in the base plate of Mu phage. Due to the
conformational change in the base plate, the tail’s sheath contracts.
Penetration : By the contraction of the tail’s sheath, the rigid
internal material gets into the host cell surface through the cell
envelope. The N protein ( non-replicative protein) also gets injected
along with the viral genome.
14.
15. Circularization:The N-protein undergoes circularization
once it binds with the viral genome.
Integration: After circularization, early transcription
occurs that gives rise to the Repc and Ner repressors and
DDE recombinase A (Mu A). These genes help in the
integration of the viral genome with the host genome.
During this step, the variable ends are cut off from the
viral genome.
16. Early phase: After the non-replicative transposition, the
ratio of Repc and Ner repressors decide whether the phage
will enter to the lysogenic phage or lytic phage.
◦Repc: It represses the early promoter by establishing
latency or lysogeny.
◦Ner: It represses the expression of Repc by promoting the
expression of the early genes for the replication of Mu
phage.
17. Middle phase
After the inactivation of Repc, there is an
expression of MuA and MuB genes. MuA is the DDE
recombinase-A enzyme, and MuB is the target DNA
activator B. MuA performs the transposition of viral
genome ends and host DNA. The target DNA activator B
helps in the replication of viral host DNA, leading to the
formation of the two copies. This type of replication is
called replicative transposition. This replication can lead
to 100 viral genomes after successive rounds.
18. Late transcription
This phase carries out the expression of the
adenine modification enzyme, which makes the viral
DNA resistant to the host restriction enzymes by
modifying the adenines in the viral DNA.
19. Biosynthesis and Assembly : The late gene synthesizes the
structural genes of Mu phage, which leads to the biosynthesis
of virus particles. Then the virus particles like empty capsid,
tail fibres etc. get to assemble.
The packaging of virion: Firstly, the bacterial DNA is first
cut on the left of the integrated Mu genome for about 50-
150bp. Then, a second cut occurs after the filling of phage
head. The packaging of viral DNA also occurs on the right
side of the Mu genome. Therefore, at different sites of the
bacterial genome, the packaging of the Mu genome will occur.
20. Cell lysis and release of virion
After packaging, the newly synthesized virions
release out of the host cell by the help of lye gene that
encodes lytic enzymes (responsible for the cell lysis).
21. Reference
◦Morgan, GJ; et al. (2002), "Bacteriophage Mu genome
sequence: analysis and comparison with Mu-like
prophages in Haemophilus, Neisseria and Deinococcus", J
Mol Biol, 317 (3): 337–
359, doi:10.1006/jmbi.2002.5437, PMID 11922669
◦Montano SP, Pigli YZ, Rice PA (2012).
◦https://biologyreader.com/mu-phage.html.