To accompany ‘Freeze-drying turned a woolly mammoth’s DNA into ‘chromoglass’

SCIENCE

Before Reading:

1. DNA is crucial for living things. Do you know why? Briefly explain what you think DNA does for us. What problem would we encounter if our cells did not contain DNA?
2. What might we learn by examining the DNA of long-extinct plants or animals? Imagine you could use DNA to learn something about an extinct species. Which would you pick? Why did you pick this particular species? Come up with one question you think DNA analysis could help to answer about it.

During Reading:

1. How old is the mammoth DNA discussed in this story?
2. Explain the relationship between DNA and chromosomes.
3. What can scientists learn about DNA using the Hi-C technique? What problem has prevented scientists from using this technique to examine ancient DNA before?
4. What did Cynthia Pérez Estrada hope to learn by testing the Hi-C technique on old turkey bones?
5. What is permafrost?
6. How does “chromoglass” differ from chromosomes?
7. How many pairs of chromosomes did woolly mammoths have?
8. What does it mean for a gene to be “turned off”?
9. How many genes did scientists find “turned on” in mammoths but not elephants?
10. What does the gene known as Egfr control?

After Reading:

1. This story discusses how genes can be turned off and on by comparing the genes in elephants and mammoths. Now think about how different cells in one organism’s body might use different genes. Consider this, for instance: A human nerve cell and a white blood cell both contain the same DNA. Yet, these cells have very different jobs in the body. How might the cell’s ability to turn genes on and off explain how two cells with the same DNA might turn out — and function — so differently? Discuss how Hi-C might be used to explore this idea further.
2. Christina Warinner says that the new PaleoHi-C technique “opens up a lot of new doors” in the study of ancient DNA. What new options might be available to researchers now — using this technique — that they lacked before? Give two scientific questions that you think PaleoHi-C might one day help to answer. For one of these questions, briefly describe a follow-up study that might try to answer this.