Bovine Spongiform Encephalopathy (BSE), Commonly Known As Mad Cow Disease, Is a Fatal

Detection of Mad Cow Disease

Brian E. Guthman

Lake Holcombe School

26331 262nd Ave.

Holcombe, WI 54745

7/16/07

Curriculum Project

Biotechnology for Teachers 707

Summer 2007

Activity Description

This lesson will help to familiarize students with Bovine Spongiform Encephalopathy (BSE) better known as mad Cow disease, is a fatal condition characterized by vacuoles (empty spaces) which form within the cytoplasm of neurons. More information using the Kit from EDVOTEK #117 student will use polymerase chain reaction (PCR) samples of grain mixtures to test for the presents of bovine protein. PCR is a powerful technique used to amplify DNA at a very specific sequence. Students will submit the samples to agarose gel electrophoresis to determine if any of the cattle feed samples contain bovine protein.

This project will fit into my Animal Science class, along with the units on genetics, DNA ,RNA , gene regulation and replication, manipulating DNA. It will also be related to the units on livestock feeding and disease. I will add this to the large animal unit and will remove some of the small animal science applications that have been included in the class.

Objectives

The students will be able to….

1.) Identify major areas of biotechnology in animal science.

2.) Explain electrophorisis methods used in biotechnology.

3.) Understand different applications of molecular biotechnology.

4.) Have a better understanding of Bovine Spongiform Encephalopathy(BSE), better known as Mad Cow Disease.

Key Concepts

How do scientists make changes to DNA?

What kind of information can the sequence of a DNA molecule give?

Vocabulary

Genetic engineering

Restriction enzyme

Gel electrophoresis

Recombinant DNA

Polmerase chain reaction (PCR)

Plasmids

Genetic markers

Background Information

Bovine spongiform encephalopathy (BSE), commonly known as mad cow disease, is a fatal, neurodegenerative disease of cattle, which infects by a mechanism that surprised biologists upon its discovery in Europe. In the UK, the country worst affected, 179,000 cattle were infected and 4.4 million killed as a precaution The disease can be transmitted to human beings who eat or inhale material from infected carcasses. In humans, it is known as new variant Creutzfeldt-Jakob disease (vCJD or nvCJD), it has killed 165 people in Britain, and six elsewhere with the number expected to rise because of the disease's long incubation period. Between 460,000 and 482,000 BSE-infected animals had entered the human food chain before controls were introduced in 1989.

A British inquiry into BSE concluded that the epidemic was caused by feeding cattle, who are normally herbivores, the remains of other cattle in the form of meat and bone meal (MBM), which caused the infectious agent to spread. The origin of the disease itself remains unknown. The current scientific view is that infectious proteins called prions developed through spontaneous mutation, probably in the 1970s, and there is a possibility that the use of organophosphorus pesticides increased the susceptibility of cattle to the disease. The infectious agent is distinctive for the high temperatures it is able to survive; this contributed to the spread of the disease in Britain, which had reduced the temperatures used during its rendering process. Another contributory factor was the feeding of infected protein supplements to very young calves instead of milk from their mothers.

To prevent the establishment and amplification of Bovine Spongiform Encephalopathy (BSE) through animal feed in the United States, FDA implemented a final rule that prohibits the use of most mammalian protein in feeds for ruminant animals. This rule, 21 CFR Part 589.2000 of the Code of Federal Regulations, became effective on August 4, 1997 (here called the BSE/Ruminant Feed regulation). Inspections of renderers, feed mills, ruminant feeders, protein blenders, pet food manufacturers, pet food salvagers, animal feed distributors and transporters, ruminant feeders, and others have been conducted to determine compliance with the BSE/Ruminant Feed regulations.

To enforce this ban, inspectors test for the presence of bovine protein in cattle feed. One method of testing uses the polymerase chain reaction (PCR) on feedstuffs. PCR is a powerful technique universally used to amplify DNA at very specific sequences. PCR uses a heat-stable enzyme know as Taq poymerase. The polymerase is mixed with two synthetic oligonucleotides know as “primers” which flank the sequences to be amplified, known as “template”. In the case of cattle feed compliance, the template would be complimentary to a bovine-specific gene. The entire PCR reaction mixture contains the template DNA, primers Tag polmerase, and reaction buffer.

In the first step of the PCR reaction the template, complimentary DNA strands are melted/separated from each other at 94 degrees C, at which temperature the Taq polmerase remains stable. In the second step, known as annealing, the sample is cooled to allow hybridization of the primers to the two strands of the target sequences. In the third step, known as extension, the temperature is raised to 72 degrees C and the Taq poymrease adds nucleotides to the primers to complete synthesis of the new complementary strands. The three steps denaturation, annealing and extension- constitutes one PCR “cycle”. This process is typically repeated for 20-30 cycles, amplifying the target sequence exponentially. PCR is preformed in a thermal cycler, which is a programmed to rapidly heat, cool and maintain samples at designated temperatures for varying amounts of time. In this experiment, the presence of an amplified product indicates the presence of bovine products in the cattle feed, in violation of the federal statute.

In this experiment, a hypothetical scenario involves the U. S. Federal Drug Administration laboratory, which has contained cattle feed samples from ten different feed mills. Using bovine specific primers, PCR has been performed on each of these samples. Students submit the samples to agarose gel electrophoresis to determine if any of the cattle feed samples contain bovine proteins, which could propagate mad cow disease.

Time line of project:

Day 1- 90 minutes Discussion Mad Cow Disease- Power point

Quick Lab –How are restriction enzymes used? Page 326 of text Materials construction paper (4 different colors), scissors, transparent tape.

Assignment Key terms

Day 2 - 90 minutes Discussion of electrophoresis, preparation of agarose gel student pgs. 8- 10 of Edvo-kit 117 and prepare the gel for electrophoresis and practice loading of gels with practice gel loading solution.

Day 3 – 90 minutes Discussion Experiment Overview student page 7, Conducting Agarose Gel Electrophoresis student pg. 13-15, Staining and visualization of DNA using Insta-Stain Methylene Blue student pgs. 16-19. Assignment Experiment Results and study questions student pg. 20

The special needs student adjustments will be addressed in the grouping of students into lab groups to work on the experiment. Grading will also reflect the students abilities as spelled out in the students IEP.

Students will be assessed on the student answers to key terms, lab page 20 of Student Guide of EDVO-Kit 117. The students also keep a BioLog on all of the information that is presented in class and it is graded each week.

The following Rubric will also be used to assess students on the experiment and related activities.

Bio-log Assignments

Name Date Unit

Criteria

1.  Made Entry

1 2 3 4 5 6 7 8 9 10

not yet minimal above average thorough

2.) Detail

1 2 3 4 5 6 7 8 9 10

few days mentioned half the time most days everyday

little detail some detail good detail excellent

3.) Neatness/ organization/clear communication

1 2 3 4 5 6 7 8 9 10

no evidence minimal above average through

4.) “My Thoughts” Entries

1 2 3 4 5 6 7 8 9 10

Vague difficult to becoming clear clearly expressed,

understand connections to other areas

5.) “My Data” Entires

1 2 3 4 5 6 7 8 9 10

Data Collected Data Collected Data collected, analyzed

Not analyzed analyzed connections made to other area

6.) “My Information” Entries

1 2 3 4 5 6 7 8 9 10

minimal evidence of good understanding Understanding is

understanding concepts of concepts evident exceptional, makes

connections

7.) Original Ideas/Higher –Order Thinking

1 2 3 4 5 6 7 8 9 10

little evidence of some evidence of strong evidence of originality

originality originality or thoughtfulness

8.) Personal Reflection

1 2 3 4 5 6 7 8 9 10

little some regular extensive

9.) Best Work Entries

1 2 3 4 5 6 7 8 9 10

low quality fair quality good quality very high quality

10.) Other

1 2 3 4 5 6 7 8 9 10

This project would relate to the following Wisconsin State Standards

Science, Standard G: Science ApplicationsPerformance Standards - Grade 12

By the end of grade twelve, students will:

G.12.1 Identify personal interests in science and technology, implications that these interests might have for future education, and decisions to be considered

G.12.3 Analyze the costs, benefits, or problems resulting from a scientific or technological innovation, including implications for the individual and the community

G.12.5 Choose a specific problem in our society, identify alternative scientific or technological solutions to that problem and argue it merits

Science, Standard A: Science ConnectionsPerformance Standards - Grade 12

A.12.1 Apply the underlying themes of science to develop defensible visions of the future

A.12.2 Show how conflicting assumptions about science themes lead to different opinions and decisions about evolution, health, population, longevity, education, and use of resources, and show how these opinions and decisions have diverse effects on an individual, a community, and a country, both now and in the future

A.12.5 Show how the ideas and themes of science can be used to make real-life decisions about careers, work places, life-styles, and use of resources

A.12.7 Re-examine the evidence and reasoning that led to conclusions drawn from investigations, using the science themes

This Project would relate to the following National Science Standards Life Science

CONTENT STANDARD C: As a result of their activities in grades 9-12, all students should develop understanding of

·  The cell

·  Molecular basis of heredity

·  Biological evolution

·  Interdependence of organisms

·  Matter, energy, and organization in living systems

·  Behavior of organisms

DEVELOPING STUDENT UNDERSTANDING

Students in grades K-8 should have developed a foundational understanding of life sciences. In grades 9-12, students' understanding of biology will expand by incorporating more abstract knowledge, such as the structure and function of DNA, and more comprehensive theories, such as evolution. Students' understandings should encompass scales that are both smaller, for example, molecules, and larger, for example, the biosphere.

Because molecular biology will continue into the twenty-first century as a major frontier of science, students should understand the chemical basis of life not only for its own sake, but because of the need to take informed positions on some of the practical and ethical implications of humankind's capacity to manipulate living organisms.

In general, students recognize the idea of species as a basis for classifying organisms, but few students will refer to the genetic basis of species. Students may exhibit a general understanding of classification. Although students may indicate that they know about cells, they may say that living systems are made of cells but not molecules, because students often associate molecules only with physical science.

Sources and resources

Animal Science Textbook

Biology Text book

EDVOTEK kit #117 instructor and student pages

BioLog assessment tools

All of the materials list on page 3 of instructions EDVO-Kit #117

Websites: http://www.bseinfo.org

http://www.beef.org

http://www.mad-cow.org

http:// www.fda.gov

http://dpi.wi.gov/students/sciintro.html

http://www.nap.edu/readingroom/books/nses/html/

http://www.edvotek.com