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Exclusion Mapping

More About Exclusion Mapping

Exclusion mapping is a technique used to map the location of a gene by successively eliminating regions of the chromosome that cannot contain the gene. This animation illustrates the chromosomes of two half sisters who have each inherited Rett syndrome. Each girl gets an X chromosome from her father and one from her mother. In the mother, X chromosomes recombine during Meiosis so that the X chromosome passed on to the daughter is actually an assortment of the two maternal chromosomes. Each sister inherited the Rett gene from their carrier mother. However, each affected chromosome went through different recombinations, and thus have different portions of the mother's normal and affected X chromosome. Because both daughters are affected, they must share parts of the chromosome that contains the Rett syndrome gene. Parts of the maternal X chromsome that are different in two daughters can be excluded as a possible location of the gene. Comparing exclusion maps from various families can further narrow the likely location of the Rett gene.

Exclusion Mapping Background

Patients do more than inspire researchers. They provide scientists with insights that guide them toward new methods for diagnosing, preventing, and treating these disorders. And by cooperating with researchers like Zoghbi and Vogelstein, patients advance our understanding of fundamental human biology.

From Lecture 4 of the 2003 Holiday Lectures Series "Learning From Patients: The Science of Medicine."


The 2003 Holiday Lectures Series "Learning From Patients: The Science of Medicine."

Exclusion Mapping Teaching Tips

The animations in this section have a wide variety of classroom applications. Use the tips below to get started but look for more specific teaching tips in the near future. Please tell us how you are using the animations in your classroom by sending e-mail to biointeractive@hhmi.org.

  1. Use the animations to make abstract scientific ideas visible and concrete.
  2. Explain important scientific principles through the animations. For example, the biological clocks animations can be used to demonstrate the fundamentals of transcription and translation.
  3. Make sure that students learn the material by repeating sections of the animations as often as you think necessary to reinforce underlying scientific principles. You can start, restart, and play back sections of the animations.
  4. Urge students to use the animations in accordance with their own learning styles. Students who are more visually oriented can watch the animations first and read the text later, while others might prefer to read the explanations first and then view the graphics.
  5. Incorporate the animations into Web-based learning modules that you create to supplement your classroom curricula.
  6. Encourage students to incorporate the animations into their own Web-based projects.

Exclusion Mapping Credits

Director: Dennis Liu, Ph.D.

Scientific Direction: Huda Zoghbi, M.D.

Scientific Content: Satoshi Amagai, Ph.D.

Animator: Chris Vargas

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