Discussion: Hoekstra Et Al

Discussion: Hoekstra et al. 2006. Beach mice January 27th, 2010

Introduction:

1. What is the natural history observation that motivated this study?

2. Why was the Mc1r gene the gene of choice in this study?

Sequencing:

3. What did the researchers find when they sequenced the Mc1r gene?

4. Why is it so cool that the SNP was not found in other Peromyscus species?

Reciprocal Intercross: Table 1

5. What is a reciprocal intercross? Write out what you think the genotypes of the parents, F1, and F2s will be if R=ancestral SNP, C=SNP mutant.

6. Why did they measure the pigment in seven body areas?

7. If the dark allele (R) were completely dominant, what would you expect the F1 to look like? What to the F1s really look like according to Table 1? 8. If the dark and light alleles were co-dominant, what would you expect the mean phenotype score to be for the F2s for each body area? What does it really look like in Table 2?

9. What does PVE mean in Table 2. Why were the researchers interested in measuring this?

Functional Tests: Figure 2

9. Why did the researchers go into all this cell biology stuff?

10. What if Figure 2A telling you? What does this say about the function of the light MC1R compared to the dark MC1R?

Variation in the Wild: Figure 3

11. Where is the light allele found? Where is it absent?

12. How is this figure a possible example of convergent evolution?

13. Why do you think the dark allele is still found on the Gulf Coast, when it seems like the light allele confers a higher fitness to mice living on the beach?