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Ghost in Your Genes

Program Overview

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DNA Helix NOVA explores how the epigenome—the body's complex chemical network that controls gene expression—plays a role in human biological destiny.

The program:

  • notes that, after mapping the human genome, researchers wondered how so few genes could account for so much diversity among the species.

  • recounts how one scientist determined how the deletion of a key sequence of DNA on human chromosome 15 could lead to two different syndromes depending on whether the deletion originated from the mother or the father.

  • explains that this was the first human evidence that something other than genes themselves could determine how genes are expressed.

  • provides an animation of two ways that scientists think the epigenome works to turn genes on and off.

  • cites differentiation as an example of the epigenome at work—during development, cells switch on or off to differentiate cell function; as the cells divide they retain a memory of their cell type.

  • notes that while the epigenome is normally incredibly stable, epigenetic switches sometimes can be thrown and later lead to disease.

  • looks at how the epigenetic profiles of two 66-year-old twins are very different from that of two 6-year-old twins, suggesting that epigenetic changes accumulate over time.

  • presents several experiments with rats that reveal how the epigenome works in an animal model.

  • reports how epigenetic changes may promote disease by silencing tumor suppressor genes or activating oncogenes.

  • reviews a clinical trial in which half the patients recovered after being treated with a drug designed to remove chemical tags silencing tumor suppressor genes.

  • presents the work of two scientists looking for an epigenetic influence on autism.

  • reports on a review of generations of historical records from a remote Swedish village that suggests epigenetic changes may be passed down through the generations.

Taping Rights: Can be used up to one year after program is recorded off the air.

Teacher's Guide
Ghost in Your Genes
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