Assume you have discovered a new Xenopus gene that codes for a RNA binding protein. You are not sure what its function is but you are interested in finding out as much as you can about the protein’s role in development of the embryo (from oocyte to tailbud stage) so that you can publish your results. You have tentatively called the protein Xp65 (Xenopus protein 65 kDa).

A) How would you go about determining where and when the gene is expressed in the embryo? Make sure that you think about all the important information that you would want to know to understand when and where this gene product might be functioning. B) Once you have established the expression profile, what might you want to do to help you understand how the gene effects development? Explain what experiments you might run, and why.

C) The protein turns out to have a role in transcriptional activation during gastrulation in addition to its RNA binding activities. What might you do to determine the targets of this protein (what it turns on)?

D) You find that the gene has an ortholog in Drosophila. What might you want to do in Drosophila that you cannot do in Xenopus? Explain why this might work in Drosophila but not Xenopus.