A presentation on Zebrafish's history, taxonomy , genetics, life cycle and future prospects of zebrafish and some of its medical implications in human life. Most importantly the major interest is to investigate those particular gene that are responsible for regenerating the heart in zebrafish so that they can be applied to human heart and help im regenerating human heart without the formation of any scar.
A knockout mouse is a mouse in which a specific gene has been inactivated or“knocked out” by replacing it or disrupting it with an artificial piece of DNA.
The loss of gene activity often causes changes in a mouse's phenotype and thus provides valuable information on the function of the gene.
A knockout mouse is a mouse in which a specific gene has been inactivated or“knocked out” by replacing it or disrupting it with an artificial piece of DNA.
The loss of gene activity often causes changes in a mouse's phenotype and thus provides valuable information on the function of the gene.
Introduction
About Drosophila
Genome of Drosophila
Life cycle
Differentiation
Development of Drosophila
* Embryonic development
* Dorsal -ventral and
* Anterior posterior development
* Body segmentation
* Homeotic gene
Conclusion
Reference
Molecular evolution, four class of chromosomal mutation, Negative Selection and Positive Selection, Mutations in DNA and protein, Neutral Theory of Molecular Evolution, Evidence supporting neutral evolution, Phylogenetic trees, Methods of Tree reconstruction
Welcome to the world of Homeotic genes. In this presentation I talk about the interesting history behind homeotic genes as to how it was discovered. Also, the various deformities in Drosophila related to mutations in homeotic genes and the characteristics of homeotic genes. I also talk about hox genes in humans and their function.
Introduction.
Definition.
Importance of transgenic animals.
Transgenic mice
Methods for introducing a foreign gene:
The retroviral vector method
The DNA microinjection method/ pronuclear microinjection
Genetically engineered embryonic stem cells
Transgenic fish
What is transgenic fish?
A few facts to know to know about transgenic fish.
Important points needed for genetic engineering (gene transfer) to produce transgenic fish.
Development of transgenic fishes.
A few examples
Auto-transgenesis.
Controlled culture of transgenic fish and feed.
Gene transfer technology for development of transgenic fishes.
Gene flow.
Food safety issues.
Conclusion.
Bibliography.
Introduction
About Drosophila
Genome of Drosophila
Life cycle
Differentiation
Development of Drosophila
* Embryonic development
* Dorsal -ventral and
* Anterior posterior development
* Body segmentation
* Homeotic gene
Conclusion
Reference
Molecular evolution, four class of chromosomal mutation, Negative Selection and Positive Selection, Mutations in DNA and protein, Neutral Theory of Molecular Evolution, Evidence supporting neutral evolution, Phylogenetic trees, Methods of Tree reconstruction
Welcome to the world of Homeotic genes. In this presentation I talk about the interesting history behind homeotic genes as to how it was discovered. Also, the various deformities in Drosophila related to mutations in homeotic genes and the characteristics of homeotic genes. I also talk about hox genes in humans and their function.
Introduction.
Definition.
Importance of transgenic animals.
Transgenic mice
Methods for introducing a foreign gene:
The retroviral vector method
The DNA microinjection method/ pronuclear microinjection
Genetically engineered embryonic stem cells
Transgenic fish
What is transgenic fish?
A few facts to know to know about transgenic fish.
Important points needed for genetic engineering (gene transfer) to produce transgenic fish.
Development of transgenic fishes.
A few examples
Auto-transgenesis.
Controlled culture of transgenic fish and feed.
Gene transfer technology for development of transgenic fishes.
Gene flow.
Food safety issues.
Conclusion.
Bibliography.
1 What is the study systemGeneral information. E.g. What is a .docxhoney725342
1 What is the study system?
General information. E.g. What is a “cell line”? Include images.
1 Why would a researcher use this study system?
The particular features of this system that make it useful. E.g. cell lines allow the study of genetically identical cells in many labs
1 What type of research questions can this study system be used to help answer?
List a few examples of research questions or general areas of research that can be addressed using this system. Elaborate a little on each, so we understand what you mean.
1 How does a researcher typically use this system?
What are the logistics of it? E.g. basic information about how they culture and propagate cell lines.
1 What are the pros and cons of this study system?
List and briefly explain any drawbacks or caveats that we should be aware of, along with particular benefits E.g. mammalian cell lines need adequate facilities and resources to be propagated, but they also allow for the study of mammalian cellular systems in vitro instead of studying another eukaryote like yeast.
6.Are there alternatives or variations on this study system?
If you can’t use this particular study system, what are your options for alternatives? E.g. Use yeast as a representative of a eukaryotic cell.
1 What is a real example from primary literature of this study system being used?
Provide a brief summary of the research that used the study system of interest, including the main objective, basic methods used, the main results, and conclusions. Include an image of at least one figure or table, along with an explanation of what that figure/table illustrates. You must provide the complete citation of the paper and/or a link to the online paper.
8.List of sources and places where we can find more information.
Background
C. elegans: A Simple Multicellular Model Organism
Scientists worldwide conduct basic research to address gaps in our knowledge in the hopes that this information can serve humanity in the future. Basic biological research seeks to answer questions of such elementary cellular and organismal activities as how cells grow, divide, die, move, store and use energy, and communicate.
Scientists use model organisms in basic research to answer these questions because model organisms offer simplified cellular systems that reproduce quickly, are easy to maintain, and are cost efficient. For example,
if a DNA mutation is known to result in a neurological disorder, more data can be generated using a model organism such as C. elegans, which reproduces and matures every 2–3 days, rather than waiting for a human child to mature and show symptoms. Commonly used basic model organisms include S. cerevisiae (yeast), C. elegans (nematode), D. melanogaster (fruit fly), and M. musculus (mouse).
Despite the seeming lack of a relationship to human beings, these model organisms have helped researchers understand the basic cellular machinery underlying a host of human pathologies such as cancer, neurological disorders, ...
Mr. Rakesh Sharma. M, M.Sc., in Applied Microbiology, Research Assistant with seven years of experience in Central Inter- Disciplinary Research Facility (CIDRF), SBV - Puducherry has joined as Research Associate in Mahatma Gandhi Medical Preclinical Research Centre (MGMPRC). A talk by him on “Zebrafish as an animal model for biomedical research” is scheduled on 19th November, 2022 (Saturday) at 2.30 pm in A1 conference hall, 1st floor Hospital block, MGMCRI.”
Introduction.
Properties of Stem Cells.
Key Research events.
Embryonic Stem Cell.
Stem cell Cultivation.
Stem cells are central to three processes in an organism.
Research & Clinical Application of stem cell.
Research patents.
Conclusion.
Reference.
Essay Mitosis and Meiosis
Mitosis Key Process
Mitosis Research Paper
Cell Biology Meiosis and Mitosis
Mitosis Research Paper
Observing Mitosis
Mitosis And Meiosis Similarities
Essay on Meiosis Vs. Mitosis
Mitosis: Interphase I And Meiosis
Mitosis: A Meiosis In Diploid Cells
The Process of Mitosis Essay
Mitosis And The Phase Of Interphase Essay
Speech On Mitosis
Mitosis Case Study
Mitosis Research Paper
Lab Report On Mitosis
Mitosis And Phase Of Mitosis Essay
Compare and Contrast Mitosis and Meiosis Essay
Mitosis Lab Report
Mitosis Research Paper
Advance Access publication 29 January, 2004
Establishment of human embryonic stem cell lines from
frozen±thawed blastocysts using STO cell feeder layers
Se-Pill Park
1,4, Young Jae Lee
1
, Keum Sil Lee
1
, Hyun Ah Shin
1
, Hwang Yoon Cho
1
,
Kil Saeng Chung
2
, Eun Young Kim
1,4 and Jin Ho Lim
3
1
Maria Infertility Hospital Medical Institute/Maria Biotech, Seoul 130-812,
2
Department of Animal Sciences, Kon-Kuk University,
Seoul 143-701 and
3
Maria Infertility Hospital, Seoul 130-812, Korea
4
To whom correspondence should be addressed at Maria Infertility Hospital Medical Institute, 103-11, Sinseol-dong,
Dongdaemun-gu, Seoul, 130-812 Korea. E-mail: [email protected] or [email protected]
S.-P.Park and E.Y.Kim contributed equally to this work
BACKGROUND: Recently, human embryonic stem (hES) cells have become very important resources for basic
research on cell replacement therapy and other medical applications. The purpose of this study was to test whether
pluripotent hES cell lines could be successfully derived from frozen±thawed embryos that were destined to be dis-
carded after 5 years in a routine human IVF-embryo transfer programme and whether an STO cell feeder layer
can be used for the culture of hES cells. METHODS: Donated frozen embryos (blastocysts or pronuclear) were
thawed, and recovered or in vitro developed blastocysts were immunosurgically treated. All inner cell masses were
cultured continuously on an STO cell feeder layer and then presumed hES cell colonies were characterized.
RESULTS: Seven and two cell lines were established from frozen±thawed blastocysts (7/20, 35.0%) and pronuclear
stage embryos (2/20, 10.0%), respectively. The doubling time of hES cells on the immortal STO cell feeder layer was
~36 h, similar to that of cells grown using fresh mouse embryonic ®broblast (MEF) feeder conditions. Subcultured
hES cell colonies showed strong positive immunostaining for alkaline phosphatase, stage-speci®c embryonic antigen-
4 (SSEA-4) and tumour rejection antigen 1-60 (TRA1-60) cell surface markers. Also, the hES colonies retained nor-
mal karyotypes and Oct-4 expression in prolonged subculture. When in vitro differentiation of hES cells was
induced by retinoic acid, three embryonic germ layer cells were identi®ed by RT±PCR or indirect immunocyto-
chemistry. CONCLUSIONS: This study indicates that establishment of hES cells from frozen±thawed blastocysts
minimizes the ethical problem associated with the use of human embryos in research and that the STO cell feeder
layer can be used for the culture of hES cells.
Key words: embryonic stem cells/frozen±thawed human blastocysts/inner cell mass/in vitro differentiation /STO cell
Introduction
Embryonic stem (ES) cells are derived from the inner cell mass
(ICM) cells of early mammalian blastocyst. These cells are
pluripotent and generally retain their long-term proliferative
potential in an undifferentiated state. Also, ES cells can
differentiate into d.
Cuckoo Search Optimization of Blebs in Human Embryonic Stem CellsIJMERJOURNAL
ABSTRACT: The main aim of this project is to segment the bleb from human embryonic stem cells (hESC). The behavior of bleb can be used to distinguish apoptotic bleb from the healthy bleb. The health of the human embryonic stem cells can be determined using the portion of bleb formed on the surface of the stem cells. The complete bleb formation contains bleb extraction and retraction. This paper uses the active contour algorithm for the segmentation of bleb from human embryonic stem cells. The output of the segmentation, input video and area of bleb can be used as an input to the optimization process. The cuckoo search algorithm is utilized for optimization, which inspired from the brooding parasitism will enhance the segmentation result. The proposed method attains the quick and accurate analysis in the bleb extraction process
zebrafish are a workhorse as a translatable research model. And there are a multitude of assays in which they’ve shown promise.
The zebrafish is perhaps one of the most frequently used model organisms for genetic and developmental studies. The zebrafish is known for its unique regenerative abilities and rapid embryonic development.
The scientific name of zebrafish is Danio rerio and it belongs to the minnow family, Cyprinidae. The fish got its common name from the presence of five uniform and pigmented horizontal stripes on the side of its body, which resemble the stripes of a zebra. The characteristic stripes of zebrafish are blue in colour and they extend from the gill cover to the end of the caudal fin.
Scientists use fluorescent proteins as markers to more easily identify certain processes or reactions during microscopy research. Green fluorescent proteins (GFP), are used to create chimeric proteins which can be expressed in cells, tissues, and whole organisms. Using directed mutagenesis, fluorescence can emit in multiple wavelengths.
Fluorescent proteins are critical to research involving embryonic and larval zebrafish since they are transparent and develop nearly all organs and musculoskeletal structures six days after fertilization. Transparent embryos thus allow researchers to observe organs or tissues marked with tissue specific expressions of fluorescent proteins as they develop. Dozens of transgenic zebrafish lines have been created which express fluorescent proteins in organs, glands, and other bodily structures.
Tissue regeneration is an emerging and exciting biomedical field. As.pdfshalins6
Tissue regeneration is an emerging and exciting biomedical field. As a scientist, choose either an
adult stem cell population or embryonic stem cells as a model system to develop a technique for
growing artificial limbs in culture. Be sure to explain why you chose your particular stem cell
and the drawbacks associated with the one that you did not choose for your experiments.
Solution
In tissue regeneration scientists choose only embryonic stem cells as a models system to develop
a technique for growing artificial limbs in culture. In case of salamanders have unusual and very
desirable characteristics of being able replicate limb. When salamanders loses a limb does not
form scab. Instead a wound epidermis forms it known as apical epithelial cells they form
blastema. This knob of stem cells is then able completely regenerate the limb, these blastemata
like MRL mice act as embryonic stem cells.
Embryonic stem cells:
1. It is pluripotent i.e., differentiate into 3 of the primary germ layers (ectoderm, endoderm,
mesoderm) this indicates that embryonic stem cells can potentially differentiate into adult human
cell if stimulated right way
Drawbacks of adult stem cells:
1.It is multipotent meaning that each can only produced limited cell type.
2. Unlike embryonic stem cells, they are much scarcer and harder to culture
so its not choosen by scientist to develop for growing artificial limbs in culture..
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 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.
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.
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.
(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.
A brief information about the SCOP protein database used in bioinformatics.
The Structural Classification of Proteins (SCOP) database is a comprehensive and authoritative resource for the structural and evolutionary relationships of proteins. It provides a detailed and curated classification of protein structures, grouping them into families, superfamilies, and folds based on their structural and sequence similarities.
What is greenhouse gasses and how many gasses are there to affect the Earth.moosaasad1975
What are greenhouse gasses how they affect the earth and its environment what is the future of the environment and earth how the weather and the climate effects.
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
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.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...
ZEBRAFISH : AS A MODEL ORGANISM.
1. ZEBRAFISH: AS A MODEL ORGANISM
PRESENTED BY GUIDED BY
Namrata Singh Prof. (Mrs) Pravati Kumari Mahapatra
M.Sc. Semester III P.G. Department of Zoology
Roll number -15 ZOO 016 Utkal University, Vani Vihar
Bhubaneswar- 751 004.
1
3. INTRODUCTION
Danio rerio, commomly
known as Zebrafish is a tropical
fresh water fish belonging to
the minnow family.
It has become another
popular model organism to
study fundamental biological
questions.
It is a small 1–1.5 inches fish
that grows easily in aquaria.
Fig. 01 Zebrafish.
3
5. 1. The Zebrafish is named for the
five uniform, pigmented,
horizontal, blue stripes on the
side of the body, which are
reminiscent of a Zebra's stripes,
and which extend to the end of
the caudal fin.
2. It is laterally compressed with
its mouth directed upwards.
DESCRIPTION
Fig.02 A Zebrafish showing arrangement
of stripes.
5
6. The Zebrafish is native to the streams of the South-
Eastern Himalayan region. The species arose in the
Ganges region in eastern India and commonly inhabits streams,
canals, ditches, ponds and slow-moving or stagnant water
bodies. Zebrafish have been introduced to parts of the United
States.
DISTRIBUTION
6
7. HISTORY
1. The use of Zebrafish as a
model organism was
pioneered at the University of
Oregon,U.S.A. by George
Streisinger in 1970.
2. He is the “Founder Father” of
Zebrafish Developmental and
Genetic Research.
Photograph 01 George Streisinger.
7
8. In 1990, the first
large scale
mutagenesis of
Zebrafish were
conducted by
Christiane Nusslein
Volhard in Oxford
University, United
Kingdom to identify
developmental
mutations .
Photograph 02 Christiane Nusslein Volhard.
8
9. Thomas Look of
Dana-Farber Cancer
Institute, Boston
uses the
translucent
Zebrafish to study
how cancer
behaves in 1995.
Photograph 03 Thomas Look.
9
10. FLOWN INTO SPACE
On 22nd July, 1976, the
Space Station, Salyut 5
was launched in which
Zebrafish was one of
the crew members.
Fig. 03 Salyut 5.
10
13. MODEL ORGANISM
1. A model organism is a non-human species that has been
widely studied, usually because it is easy to maintain and
breed in a laboratory setting and has particular experimental
advantages.
2. They are used in the laboratory to help scientists understand
biological processes.
13
14. ADVANTAGES
Advantages of Zebrafish as a model organism:
1. Optically translucent embryos
2. Rapid hatching of eggs
3. Maintenance cost is significantly lower than those for
mammals.
4. Amenable for molecular and genetic analysis.
5. As Zebrafish eggs are fertilized and develop outside the
mother’s body it is an ideal model organism for studying
early development.
14
15. GENETICS
1. 70% of protein-coding human genes are related to genes
found in the Zebrafish.
2. 84% of genes known to be associated with human disease
have a Zebrafish counterpart.
3. They can be cloned from somatic cells.
4. They can be made transgenic.
5. As a vertebrate, the Zebrafish has the same major organs
and tissues as humans. Their muscle, blood, kidney and eyes
share many features with human systems.
15
16. ZEBRAFISH AS A MODEL IS USED TO STUDY
1. Regeneration of heart
2. Tail regeneration
3. Retinal regeneration
4. Human pigmentation
5. Cancer research
6. Autism.
16
17. HEART REGENERATION
Mammals respond to a myocardial
infarction by irreversible scar formation. By
contrast, the Zebrafish are able to resolve the
scar and to regenerate functional cardiac
muscle.
The reparative and regenerative process
is achieved through Smad3-dependent TGFβ
signaling.
17
18. 7. During a heart attack, heart muscle cells are deprived of oxygen and
they die, leaving scar tissue
8. Scientists are working to find out the specific factors involved in this
process to see if this will help us to develop ways of repairing the
heart in humans with heart failure or who have suffered heart
attacks.
18
19. MECHANISM
Zebrafish heart regeneration can be sub-divided
into three overlapping phases:
A. Inflammatory phase
B. Reparative phase
C. Regenerative phase.
19
20. INFLAMMATORY PHASE
First, myocardial
cell death triggers
an inflammatory
response that is
characterized by the
infiltration of the
infarct with
activated leukocytes
and fibroblasts-like
cells which express
TGFβ ligands
Fig.06 Mechanism of inflammatory
phase. 20
21. REPARATIVE PHASE
Second as the
wound becomes
cleared of the
dead cells and
matrix debris, the
reparative phase
begins, TGFβ
stimulates the
recruited
fibroblast-like cells
to synthesize
collagen rich ECM.
Fig. 07 Mechanism of reparative
phase. 21
22. REGENERATIVE PHASE
At the onset of scar
formation, the
regenerative phase
begins. While the
fibrotic tissue is still
maturing TGFβ signaling
promotes proliferation
of the cardiomyocytes
located in the vicinity of
the post-infarct.
Fig.08 Mechanism of regenerative
phase. 22
23. Tissue remodeling and invasion of new cardiac muscle
to replace scar issue are associated with TGFβ dependent
expression of Tenascin-C, an extracellular protein with
contra-adhesive properties.
Thus, the regenerative phase is characterized by two
opposing processes:
1. scar deposition in the damaged area
2. scar degradation at the position where new
cardiomyocytes invade the post-infarct.
23
24. TAIL FIN REGENERATION
1. Zebrafish fins are complex appendages that quickly and reliably
regenerate after amputation, restoring both size and shape.
2. The key regenerative units are their many rays of dermal bone,
which are segmented and lined by osteoblasts.
3. An amputated fin ray is covered within the first several hours by
epidermis, and within one to two days, a regeneration blastema
forms. The blastema is a proliferative mass of morphologically
similar cells, formed through disorganization and distal migration
of fibroblasts and osteoblasts.
4. Blastema formation is the only one step in zebrafish tail fin
regeneration.
5. Wnt signaling positively regulate blastemal proliferation and
outgrowth.
24
28. RETINAL REGENERATION
Another notable characteristic of the Zebrafish is that it possesses
four types of cone cells, with ultraviolet-sensitive cells
supplementing the red, green and blue cone cell subtypes found
in humans. Zebrafish can thus observe a very wide spectrum of
colors. The species is also studied to better understand the
development of the retina; in particular, how the cone cells of the
retina become arranged into the so-called cone mosaic.
28
29. The researchers studied Müller glial cells in the eyes of humans
aged from 18 months to 91 years, and were able to develop
them into all types of retinal neurons. The stem cells of
Zebrafish successfully migrated into diseased rats' retinas, and
took on the characteristics of the surrounding neurons. The
team stated that they intended to develop the same approach
in humans.
Stem cells from Zebrafish, the staple of genetic research, could
regenerate damaged cones in retinas and restore eyesight to
people.
Fig.12 Regeneration of retina.
29
30. Zebrafish solves the mystery of our skin
color. Embryonic patterning of pigmentation
in D. rerio is highly investigated area of study.
SLC24A5 is shared both by humans and
Zebrafish and makes melanosomes less
abundant, less concentrated and smaller in
lighter skinned humans or light-striped
Zebrafish.
HUMAN PIGMENTATION
30
31. While some researchers were studying Zebrafish to find cancer
genes, they found that pigment cells of Zebrafish looked similar to
pigment cells in light-skinned humans. Since then, many
researchers have investigated the Zebrafish gene responsible for
different colors in stripes.
In 2005, some studies found the human version of the
gene, which affected Europeans differently from Africans and
Asians.
Fig.13 Location of pigment cells in Zebrafish embryo.
31
32. At embryonic and early larva
stage, the neural crest cells gets
differentiated into three cells
displaying alternating stripes:
1. Melanocytes (blue)
2. Iridiophores (silver)
3. Xanthophores (yellow).
Further study in Zebrafish
pigment cells is essential, since
they provide many opportunities
to learn the nature of the human
skin color.
Fig.14 Patterns of Zebrafish.
32
33. 1. Zebrafish have been used to make
several transgenic models of cancer,
including melanoma, leukemia,
pancreatic cancer, colon cancer.
2. Researchers have created a model of
cancer in Zebrafish that allows them to
capture live images of tumors forming
and growing.
IN CANCER RESEARCH
Fig.15 Tumor in Zebrafish.
33
34. STAINING THE CELL
1. In Zebrafish, the endothelial cells are
stained with a fluorescent protein.
2. The fluorescent stained tumor cells are
highlighted in the transparent Zebrafish
embryos and larvae.
3. Now, the process of metasizing tumor cells
can be accurately tracked at cellular level.
34
35. XENOTRANSPLANTATION AND METASTASIS
During zebrafish
development, a cluster of neural
cells called the "posterior lateral
line primordium" (PLLp) mimics
the behavior of metastasizing
human cancer.
The cluster of zebrafish
neural cells travels the entire
length of the embryo, driven by
the same molecular pathways
that drive human cancer cells to
new sites in the body.
So, if we can find drugs that
block it then we can also find
drugs that potentially block
cancer metastasis in humans as
well.
Fig. 16 Transplantation and metastasis.
35
36. DISCOVERY OF A DRUG
Rosuvastatin prevents the
spreading of cancerous cells in
Zebrafish from one part to
another.
The same drug was then
tested on human cancer cells,
and it had the same migration-
stopping effect on both
leukemia and pancreatic
cancer cells.
Fig. 17 3D Structure of
Rosuvastatin.
36
37. AS A MODEL TO STUDY AUTISM
Zebrafish model gives new insight on autism spectrum
disorder. A team of researchers at Massachusetts Institute of
Technology focused on genes that have been found to be either
missing or copied in about 1% of patients with autism. Their study
revealed that when they deleted these genes from Zebrafish
embryos, nearly all the fish developed brain abnormalities.
It is found that estrogens, the primary female sex
hormone, could reverse abnormal behavior in Zebrafish carrying a
mutation in CNTNAP2, a gene linked to genes of autism in
humans,SYNGAP1 and SHANK3.
The researchers found that Zebrafish carrying the
CNTNAP2 mutation are more prone to seizures than Zebrafish
without the mutation.
37
39. Genome sequencing
1. The Wellcome Trust Sanger Institute, U.K. was the first to
start the Zebrafish Genome Sequencing Project.
2. In 2009, Institute of Genomics & Integrative
Biology, New Delhi reported sequenced genes in Zebrafish.
3. The paper “The zebrafish reference genome sequence and
its relationship to human genome” was published in Nature
in 17th April, 2013.
Its genome (1.4 x 109 base pairs) has been
sequenced revealing 26,606 protein-coding genes. The
Zebrafish genome has been fully sequenced to a very high
quality. This has enabled scientists to create mutation in more
than 14,000 genes to study their function.
39
40. GloFish
1. The GloFish is
a patented brand
of genetically modified
fluorescent fish. Different
varieties of GloFish are
currently available in the
market. Zebrafish were
the first GloFish available
in pet stores.
2. These fish are a valuable
tool for examining
erythrocyte development
and circulation defects in
the developing embryo.
Fig.19 GloFish in aquarium.
40
41. GENE EXPRESSION
1. Due to their short lifecycles and relatively large clutch sizes,
Zebrafish are a useful model for genetic studies.
2. Morpholino antisense technology reduces gene expression.
Morpholino oligonucleotides (MO) are stable,
synthetic macromolecules that contain the same bases as DNA
or RNA; by binding to complementary RNA sequences, they can
reduce the expression of specific genes or block other processes
from occurring on RNA.
41
42. DRUG DISCOVERY
As demonstrated through ongoing
research programmes, the Zebrafish model
enables researchers not only to identify genes
that might underlie human disease, but also
to develop novel therapeutic agents in drug
discovery programmes.
42
43. ENVIRONMENTAL MONITORING
1. The researchers cloned estrogen-sensitive genes and
injected them into the fertile eggs of Zebrafish.
2. The modified fish turned green if placed into water that was
polluted by estrogen.
43
44. ZEBRAFISH WEBSITES
1. The Zebrafish Server
2. The Fishnet
3. ZFIN- Zebrafish Information Network.
44
45. Zebrafish Labs in India
1. Institute of Genomics and Integrative Biology
(New Delhi)
2. Center for Cellular and Molecular Biology
(Hyderabad)
3. Indian Institute of Sciences (Bangalore)
4. Tata Institute of Fundamental Research
(Mumbai)
5. Institute of Life Sciences (Hyderabad)
6. National Centre for Radio Astrophysics
(Pune). 45
46. FUTURE PROSPECTS
As Zebrafish are now being used in virtually
all disciplines, from neurogenesis to oncogenesis, from
behavior to genetics, its popularity is steadily
increasing.
The emergence of Zebrafish Conferences and
the increasing presence of Zebrafish studies at large
annual meetings are also boosting the use of Zebrafish
as an appropriate model organism.
46
48. REFERENCES
Chablais F, Jazwinska A (2012) The regenerative capacity of the zebrafish
heart is dependent on TGFβ signaling. Development and Stem
Cell, 139(10): 1921-1930.
Gilbert SF(2010) Developmental Biology. 9th Edition. Sinauer Associates, Inc.
Sunderland, Massachusetts, USA, pp 323- 332.
Hsu CH, Wen ZH, Lin CS, Chakraborty C (2007) The zebrafish model: use in
studying cellular mechanism for a spectrum of clinical disease entities.
current neurovascular reseasrch, 4(2): 111-120.
Slack JMW (2006) Essential Developmental Biology. 2nd Edition. Blackwell
Publishing Ltd., Malden, USA, pp 61-89.
48