Alternative splicing is a deviation from the conventional splicing as it removes introns in a different manner. It has a lot of significance in the development of diseases like cancers and in plants adapting to various stress conditions.
Introduction
What RNA Splicing???
Discovery
Types
Alternative Splicing
Mechanism
Regulatory element And protein
Splicing repression
Splicing activation
Significance
Diseases
Conclusion
Refrences
Regulation of gene expression in eukaryotesAnna Purna
Presence of nucleus and complexity of eukaryotic organism demands a well controlled gene regulation in eukaryotic cell. Tissue specific gene expression is essential as they are multicellular organisms in which different cells perform different functions. This PPT deals with various control points for the gene regulation and expression within a cell.
Alternative splicing is a deviation from the conventional splicing as it removes introns in a different manner. It has a lot of significance in the development of diseases like cancers and in plants adapting to various stress conditions.
Introduction
What RNA Splicing???
Discovery
Types
Alternative Splicing
Mechanism
Regulatory element And protein
Splicing repression
Splicing activation
Significance
Diseases
Conclusion
Refrences
Regulation of gene expression in eukaryotesAnna Purna
Presence of nucleus and complexity of eukaryotic organism demands a well controlled gene regulation in eukaryotic cell. Tissue specific gene expression is essential as they are multicellular organisms in which different cells perform different functions. This PPT deals with various control points for the gene regulation and expression within a cell.
"Introns: Structure and Functions" during November, 2011 (Friday Seminar activity, Department of Biotechnology, University of Agricultural Sciences, Dharwad, Karnataka) by Yogesh S Bhagat (Ph D Scholar)
Structure and function of Messenger RNA (mRNA )ICHHA PURAK
This presentation of 42 slides delivers information about structure,function synthesis , life span of both prokaryotic and eukaryotic messenger RNA also about role in protein sorting and targetting
RNA transport
Multiple classes of RNA are exported from the nucleus
Transportation through nuclear pore complex.
Ribosomal subunits are assembled in the nucleolus and exported by exportin 1
tRNAs are exported by a dedicated exportin
Messenger RNAs are exported from the nucleus as RNA-protein complexes
Messenger RNAs are exported from the nucleus as RNA-protein complexes
hnRNPs move from sites of processing to NPCs
Precursors to microRNAs are exported from the nucleus and processed in the cytoplasm
It is the DNA located in the mitochondria.Mitochondrial DNA (mtDNA or mDNA) is the DNA located in the mitochondria.
They are double stranded circular DNA molecule.
It is only 16 kb in length – contains 16,600 bp.
It is haploid in nature.
It codes for 37 genes.
13 genes provide instructions for making enzymes involved in oxidative phosphorylation.
It is a process that uses oxygen and simple sugars to create ATP, the cells main energy source.
"Introns: Structure and Functions" during November, 2011 (Friday Seminar activity, Department of Biotechnology, University of Agricultural Sciences, Dharwad, Karnataka) by Yogesh S Bhagat (Ph D Scholar)
Structure and function of Messenger RNA (mRNA )ICHHA PURAK
This presentation of 42 slides delivers information about structure,function synthesis , life span of both prokaryotic and eukaryotic messenger RNA also about role in protein sorting and targetting
RNA transport
Multiple classes of RNA are exported from the nucleus
Transportation through nuclear pore complex.
Ribosomal subunits are assembled in the nucleolus and exported by exportin 1
tRNAs are exported by a dedicated exportin
Messenger RNAs are exported from the nucleus as RNA-protein complexes
Messenger RNAs are exported from the nucleus as RNA-protein complexes
hnRNPs move from sites of processing to NPCs
Precursors to microRNAs are exported from the nucleus and processed in the cytoplasm
It is the DNA located in the mitochondria.Mitochondrial DNA (mtDNA or mDNA) is the DNA located in the mitochondria.
They are double stranded circular DNA molecule.
It is only 16 kb in length – contains 16,600 bp.
It is haploid in nature.
It codes for 37 genes.
13 genes provide instructions for making enzymes involved in oxidative phosphorylation.
It is a process that uses oxygen and simple sugars to create ATP, the cells main energy source.
Course: Bioinformatics for Biomedical Research (2014).
Session: 4.1- Introduction to RNA-seq and RNA-seq Data Analysis.
Statistics and Bioinformatisc Unit (UEB) & High Technology Unit (UAT) from Vall d'Hebron Research Institute (www.vhir.org), Barcelona.
RNA- A polymer of ribonucleotides, is a single stranded structure. There are three major types of RNA- m RNA,t RNA and r RNA. Besides that there are small nuclear,micro RNAs, small interfering and heterogeneous RNAs. Each of them has a specific structure and performs a specific function.
RNA interference (RNAi) is a mechanism that inhibits gene expression at the stage of translation or by hindering the transcription of specific genes.
RNAi targets include RNA from viruses and transposons.
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 describes various co-transcriptional and post-transcriptional RNA modifications in eukaryotic cells. The following processes are described in detail:
1. 5' mRNA Capping
2. Splicing
3. Alternative Splicing
4. 3' Polyadenylation
5. RNA Editing
Enjoy Reading.
Post-transcriptional modification or co-transcriptional modification is a set of biological processes common to most eukaryotic cells by which an RNA primary transcript is chemically altered following transcription from a gene to produce a mature, functional RNA molecule
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.
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
Thanks...!
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.
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
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.
Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...Ana Luísa Pinho
Functional Magnetic Resonance Imaging (fMRI) provides means to characterize brain activations in response to behavior. However, cognitive neuroscience has been limited to group-level effects referring to the performance of specific tasks. To obtain the functional profile of elementary cognitive mechanisms, the combination of brain responses to many tasks is required. Yet, to date, both structural atlases and parcellation-based activations do not fully account for cognitive function and still present several limitations. Further, they do not adapt overall to individual characteristics. In this talk, I will give an account of deep-behavioral phenotyping strategies, namely data-driven methods in large task-fMRI datasets, to optimize functional brain-data collection and improve inference of effects-of-interest related to mental processes. Key to this approach is the employment of fast multi-functional paradigms rich on features that can be well parametrized and, consequently, facilitate the creation of psycho-physiological constructs to be modelled with imaging data. Particular emphasis will be given to music stimuli when studying high-order cognitive mechanisms, due to their ecological nature and quality to enable complex behavior compounded by discrete entities. I will also discuss how deep-behavioral phenotyping and individualized models applied to neuroimaging data can better account for the subject-specific organization of domain-general cognitive systems in the human brain. Finally, the accumulation of functional brain signatures brings the possibility to clarify relationships among tasks and create a univocal link between brain systems and mental functions through: (1) the development of ontologies proposing an organization of cognitive processes; and (2) brain-network taxonomies describing functional specialization. To this end, tools to improve commensurability in cognitive science are necessary, such as public repositories, ontology-based platforms and automated meta-analysis tools. I will thus discuss some brain-atlasing resources currently under development, and their applicability in cognitive as well as clinical neuroscience.
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.
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
2. Introduction
The number of introns found within a gene
varies from one in the yeast genes (and a few
human genes), to 50 in the case of the
chicken proᾳ2 collagen gene
to as many as 363 in the case of the Titin
gene of humans. Also, the sizes of the exons
and introns vary.
3. a typical eukaryotic gene in which the
coding region is interrupted by three
introns, splitting it into four exons
4. Introduction
introns are very much longer than the exons.
for example, exons are order of 150
nucleotides, whereas can be as long as
800,000 nucleotides (800 kb).
other example, the mammalian gene for the
enzyme dihydrofolate reductase is more than
31 kb long, and contain six exons that
correspond to 2 kb of mRNA.
Thus, in this case, the coding portion of the
gene is less than 10% of its total length.
5. Introduction
In the extreme case of the human
dystrophin gene, RNA polymerase must
traverse 2,400 kb of DNA copy (entire
gene) into RNA. (transcription rate is 40
nucleotides per second, it require 17
hours to make a single transcript of this
gene!)
Alternative splicing, or differential splicing,
is mean a single gene coding for multiple
proteins.
6. 60% of the genes in the human genome are spliced in
alternative ways to generate more than one protein per gene.
For extra example, Drosophila gene & the Slo gene from rat
which encodes a potassium channel expressed in neurons has
the potential to encode 500 alternative versions of that product.
7. THE CHEMISTRY OF RNA SPLICING
Sequences within the RNA Determine Where Splicing occurs
the exon-intron boundary at 5' end is marked by a sequence
called the 5' splice site.
The intron-exon boundary at 3' end of the intron is marked by the
3' splice site. (it was called the donor and acceptor sites)
third sequence necessary for splicing is called the branch point
site (or branch point sequence). It is found entirely within the
intron, usually close to its 3' end, and is followed by a
polypyrimidine tract (Py tract),
The most highly conserved sequences are the GU in the 5' splice
site, the AG in the 3' splice site, and the A at the branch site.
8. the chemistry of splicing achieved by two
transesterification reactions in phosphodiester
linkages within the pre-mRNA are broken and new ones
are form
The first reaction is triggered by the 2 OH of the
conserved A at the branch site.
This group acts as a nucleophile to attack the
phosphoryl group of the conserved G in the 5' splice
site. the phosphodiester bond between the sugar and
the phosphate at the junction between the intron and
the exon is cleaved and the freed 5' end of the intron
is joined to the A within the branch site.
So the 5' exon is a leaving group in the first
transesterification reaction
9.
10. Thus, in addition to the 5' and 3' backbone linkages, a
third phosphodiester extends from the 2'OH of that A to
create a three-way junction.
11. In the second reaction, the 5' exon reverses its role and
becomes a nucleophile that attacks the phosphoryl group at the
3' splice site This second reaction has two consequences :-
First, and most importantly, it joins the 5' and 3' exons thus, this
is the step in which the two coding sequences are actually
"spliced" together.
Second, this same reaction liberates the which serves as a
leaving group.
12. Because the 5' end of the intron had been joined to the branch
point A in the first transesterification reaction, the newly
liberated intron has the shape of a lariat.
In the two reaction steps, there is no net gain in the number of
chemical bonds two phosphodiester bonds are broken, and two
new ones made. As it is just a question of shuffling bonds, no
energy input is demanded by the chemistry of this process.
But, as we shall seebelow, a large amount of ATP is consumed
during the splicing reaction. This energy is required, not for the
chemistry, but to properly assemble and operate the splicing
machinery
13. is the splicing reaction direction only goes forward?
Two features that could contribute to this are as follows.
First, the forward reaction involves an increase in entropy a
single pre-mRNA molecule is split into two molecules, the
mRNA and the liberated lariat.
Second, the excised exon is rapidly degraded after its removal
and so is not available to partake in the reverse reaction
14. Exons from Different RNA Molecules Can Be Fused by
Transsplicing
In some cases, two exons carried on different RNA molecules
can be spliced together in a process called transsplicing.
Although generally rare, transsplicing occurs in almost all the
mRNAs of trypanosomes. In the nematode worm (C. elegans),
all mRNAs undergo transsplicing (to attach a 5' leader
sequence), and many of them undergo cissplicing as well.
15. Trans-Splicing. In transsplicing
two exons, initially found in two
separate RNA molecules, are
spliced together into a single
mRNA. The chemistry of this
reaction is the same as that of
the standard splicing reaction
described previously, and the
spliced product is
indistinguishable. The only
difference is that the other
product-the lariat in the standard
reactionis, in transsplicing, a Y
shaped branch structure instead.
This is because the initial
reaction brings together two
RNA molecules rather than
forming a loop within a single
molecule
16. THE SPLICEOSOME MACHINERY RNA Splicing Is Carried
Out by a Large Complex Called the Spliceosome
The five RNAs (U1, U2, U4, U5, and U6) are collectively called
small nuclear RNAs (snRNAs).
Each of these RNAs is between 100 and 300 nucleotides long
and is complexed with several proteins.
These RNA protein complexes are called small nuclear
ribonuclear proteins pronounced "snurps").
The spliceosome is the large complex made up of these
snRNPs, but the exact makeup differs at different stages of the
splicing reaction
17. The snRNPs have three roles in splicing:
1.They recognize the 5' splice site and the branch site
2. they bring those sites together as required.
3. they catalyze (or help to catalyze) the RNA cleavage and
joining reactions.
To perform these functions, RNA-RNA RNA-protein, and
protein-protein interactions are all important.
Some RNA-RNA hybrids formed during the splicing reaction. In
four cases :
a) different snRNPs recognize the same sequences in the pre-
mRNA at different stages of the splicing reaction U1 and U6
recognizing the 5' splice site.
(b) snRNP U2 is shown recog- nizing the branch site.
18.
19. (c) the RNA:RNA pair- ing between the snRNPs U2 and U6 is
shown.
(d), the same sequence within the pre-mRNA is recognized by a
protein example,
U2AF (U2 auxillary factor), recognizes the polypyrimidine (Py)
tract/3' splice site, and, in the initial step of the splicing reaction,
helps another protein,
branch-point binding protein (BBP), bind to the branch site. BBP
is then displaced by the U2 snRNP
.