Use of C. Elegans as a biological model

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Use of C. Elegans as a biological model

• Darlene Jones
• Columbia High School, Columbia Brazoria ISD
• Dr. John Ford, Associate Professor, Dept. of
  Nuclear Engineering, TAMU

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Dr. Fords Research Group
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Radiological Health EngineersRadiation
Biologists Health/Medical Physicists
Health physicists are involved in understanding,
evaluating, and controlling the potential risks
to the population from radiation relative to its
benefits
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RESEARCH QUESTION Do the cells surrounding a cell
exposed to ionizing radiation exhibit cellular
mutations because of the radiation exposure?

• Why is C. elegans used in research?
• Organism has simple growth conditions and
  reproduces rapidly with a life span of
  approximately 2-3 weeks.
• The cell lineage of the organism is known and
  does not vary.
• The organism can be easily genetically engineered
  for research purposes.
• The genome for C. elegans has been completely
  sequenced.

Dr. Fords research used the organism C. elegans.
C. elegans is a nematode that lives in the
soil, eats bacteria, and is about 1 mm in length.
It is an excellent in vivo (in living) model
for biology studies.
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RESEARCH EXPERIMENT Worms were selected that were
in the L1 stage. They were placed in an
anesthesia and a single cell in the intestinal
tract of the worm was targeted and exposed to
ionizing radiation using the accelerator beam
line and stage shown below. The worms were then
allowed to continue growing and when they reached
L4 (adult) stage, they were fixed using a DNA
stain and observed for any mutations.
Particle Source
Accelerator Beam line
Collimator and Irradiation Stage
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RESEARCH RESULTS Examples of Anaphase Bridges in
Non-targeted Cells
Worm 95
Worm 66
Worm 96
Worm 50
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BYSTANDER EFFECT An effect/change in the cells
surrounding the irradiated cell. This slide
illustrates the increase in p53 (transcriptase
enzyme) levels and elevated SCE levels (Sister
Chromatid Exchange) in the cells that surround
the irradiated cell

• These observations then raise these questions
• Is the bystander effect good or bad?
• How is this signal communicated between these
  cells?
• Future research will attempt to answer these
  questions.

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HOW IS THIS RESEARCH RELEVANT?
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• Classroom Project
• Project Target AP Biology 12th Grade
• Objectives
• Exploration of Engineering Careers
• Overview of Radiation sources and the publics
  exposure to radiation
• Exploration of the use of genetic engineering by
  integrating the biological model C. elegans
  mutants in a lab exercise
• Implementation of the engineering design process
  by students utilizing the worms
• Reinforcement Presentation and Q A from a
  radiation health engineer (health physicist)
  from STPNOC

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TEKS CITED IN THE LESSONS 1A demonstrate safe
practices during laboratory investigations 1B
demonstrate an understanding of the use and
conservation of resources and the proper disposal
of materials 2E plan and implement experimental
investigations, selecting equipment and
technology 2F collect data and measurements
using tools such as microscopes, computers,
micropipettors, thermometers, petri dishes,
biological specimens 2G analyze, evaluate, make
inferences, and predict trends from data 2H
communicate valid conclusions 3A analyze,
evaluate, and critique scientific explanations 3B
communicate scientific information gathered from
journals, news reports 3D evaluate the impact of
scientific research on society and the
environment 3F research and describe the history
of biology and contributions of scientists 5A
describe the stages of the cell cycle, including
DNA replication, mitosis, and the importance of
the cell cycle. 5C describe the roles of DNA,
RNA and environmental factors in cell
differentiation
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5D recognize that disruptions of the cell cycle
lead to deseases such as cancer 6A identify
components of DNA and describe how information
for traits of an organism is carried in DNA 6B
recognize that components that make up the
genetic code are common to all organisms 6C
explain the purpose and process of transcription
and tanslation using models of DNA and RNA 6D
recognize that gene expression is a regulated
process 6E identify and illustrate changes in
DNA and evaluate the significance of these
changes 6H describe how techniques such as
genetic modification is use to study the genomes
of organisms
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Some Possible PRE-TEST questions

• Radiation is
• Spokes on a wheel
• B. Energy found only in space
• C. Spontaneous emission of a stream of particles
  or electromagnetic rays in nuclear decay
• D. The visible part of the electromagnetic
  spectrum

2. Cancer is A. Always characterized by large
deadly tumors. B. A disease that only humans can
get. C. Any malignant growth or tumor caused by
abnormal and uncontrolled cell division D.
Characterized by growths that are benign

• 3. C. elegans is what type of organism?
• Insect
• Mammal
• Reptile
• D. Nematode

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Exploration of Engineering Careers First Six
Weeks
Duration 2 Days TEKS 3A,3B,3D

• Students prepare a 10 minute power point
  presentation on a STEM career.
• Must explain required high school classes and
  university graduation requirements. Must include
  average compensation for graduates.
• A Day in the Life of .
• Sample choices Biomedical Engineering,
  Environmental Engineering, Genetic Engineering,
  Radiation Health Engineering, Chemical
  Engineering, Engineering Technology Computer
  Engineering

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Exploration Explanation of Radiation Second
Six Weeks
Duration 2 Days TEKS 2C,2G,2H.3D
The class will explore the topic of radiation.
Engage - show the video Debating the Facts on
Radiation highlighting our exposure to
different forms of radiation. Explain Short
teacher lecture and handouts on the topic of
radiation (source- NRC website) Explore-
Students will work through the online calculator
on the Nuclear Regulatory Commission website.
Students will perform a lab, predicting which
everyday objects are radioactive. Students will
predict which materials will shield /block
radiation. Students will measure the amount of
radiation given off by the objects with a Geiger
counter if available.
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Radiation Dose Calculator Worksheet
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Duration 1 Day TEKS 1B,3D,3F
A guest speaker from the Health Physics
department at the South Texas Project Nuclear
Power Plant will be invited to the classroom to
discuss their responsibilities at the nuclear
power facility. This will also include a Q A
session. This will be the lead in activity for
the discussion of Dr. Fords research. This also
provides students with the real world relevancy
of STEM curriculum.
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As the class progresses through our study of DNA
and the cell cycle, I will introduce the power
point highlighting the research project conducted
in Dr. Fords lab using the C. elegans to study
the effects of radiation on adjacent cells in
tissue. Engage teacher lecture with power
point. Explore-Student web based research on C.
elegans Evaluate Quiz on C. elegans facts
Cell Cycle
Duration 3 Days TEKS 3A,3B,3D,3E,3F 5A,5C,5D,6E
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Using C. elegans as a Biological Model Third
Six Weeks

• The core element that I am adapting from Dr.
  Fords research is the use of C. elegans in my
  classroom.
• The lab specimens will be ordered from Carolina
  Biological. Upon conclusion of our unit on
  protein synthesis and gene expression, the
  students will begin a lab using C. elegans.
• The worms are fed lab strains of E. coli that
  express (dsRNA) corresponding to either of 2
  target genes. The dsRNA initiates the
  destruction of mRNA expressed from the target
  genes. One will silence the bli-1 gene that will
  produce a worm with blisters on its cuticle.
  The other type will silence the dpy-11 gene
  (DMPY) and produce a short worm.
• The lab will take 10 Days from start to
  completion. Time
• for the lab will be available in AP Biology, as
  this activity
• covers numerous concepts. AP Biology is a Senior
  level course, not
• under the TAKS time restraints, the AP Exam is
  given in May.
• They will have to practice sterile technique and
  use
• a dissecting microscope, micropipettors, and
  petri dishes

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Lab Materials AP Biology C. elegans
Duration 10 Days TEKS 1A,1B,2F,2H6A,6B,6C,6D,6E,
6H
Source Carolina Biological Supply
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Wild Type and Mutants used in Lab Experiment
Wild type Very active graceful
serpentine movement and tracks in agar
bli-1 Adult worms develop blisters in their
cuticle
dpy-11 Shorter than wild type
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TEKS 1A,2E,2F,2G,3A,3B,5C,

Problem 1 Lab Extension

• Students will be given a problem to solve using
  the worm cultures. They will be given the
  question Can we reverse the phenotypes
  expressed in the worms (dumpy and blisters)?
• Students will define the goals and identify the
  constraints.
• Students will research information on C. elegans.
  Students will need to use their knowledge of C.
  elegans life cycle in order to design an
  experiment to answer the question and solve the
  problem

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Engineering Design Process 2 Lab Extension
Students will be given this problem scenario
Two food sources are available for your
consumption. One is contaminated with E. coli
and the other is clean. The E. coli bacteria are
too small to be seen, and the only tools
available to the students is the stock of C.
elegans worms and a dissecting microscope to
observe them. They must design a bacteria
detector using the worms in order to determine
which food source is safe.
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Students will follow the steps of engineering
design
TEKS 1A,2E,2F,2G,3A3B,5C

• Students will define the problem and identify the
  constraints.
• There are multiple constraints to consider
  the distance between the worm food source,
  effective transfer of the worms, whether or not
  they should be fluid or air, effect of
  temperature, etc
• Students will research and gather information.
• The internet Wormbook and Worm Atlas,
  and Journal articles provided by the teacher.
• Students will create potential design solutions.
• Considerations materials to build mazes
  on the
• agar plates could include straws, toothpicks,
  wooden
• block stamps, or placing the worms in the center
  of
• plate with samples surrounding them.
• Students will analyze and choose the most
  appropriate solution.
• Students will brainstorm designs and
  construct top two designs to test with the
  worms.

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• Students will implement their design.
• Students will construct the mazes on the
  agar plates which allow them to track the worms
  movements.
• Students will test and evaluate the design.
• Students will load the worms and test the
  effectiveness of their Bio-Bacteria Detectors
• Students will repeat as needed.
• Students will be required to turn in a written
  summary of the design process. Scoring rubric
  will apply.

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Example of a possible design for the Bio-Bacteria
Detector
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ACKNOWLEDGEMENTS
Texas A M University E3 Program Dr. John
Ford TAMU Nuclear Engineering National Science
Foundation Nuclear Power Institute Texas
Workforce Commission
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References

• http//www.nrc.gov/reading-rm/basic-ref/teachers/u
  nit1.html
• http//www.youtube.com/watch?vllgvpBPiCyI Get
  the facts Radiation Exposure in upstate North
  Carolina
• http//avery.rutgers.edu/WSSP/StudentScholars/proj
  ect/introduction/worms.html
• http//ritter.tea.state.tx.us/rules/tac/chapter112
  /ch112c/html
• www.rsc.org/loc, Maze exploration and learning
  in C. elegans
• www.carolina.com
• http//wiki.answers.com/Q/What_is_an_engineering_
  design_algorithmixzz1QWsrk7Uo
• http//www.essap.tamu.edu