Question

You are a scientist in a lab that studies how cell fates are specified during development. In particular, you are curious about muscle development. Muscle cells are derived from the mesoderm (one of the three primary germ layers) and are specified rather early in development. You are using the fruit fly, Drosophila melanogaster, as a model system to study the phenomenon of muscle fate specification. You have isolated a line of mutant flies you have named “whimpy” (wpy). The wpy phenotype appears to be inherited in a mendelian manner and acts as a recessive lethal, that is, ¼ embryos from matings between two “carrier” flies die early in development. Analysis of the embryos suggests that muscle cells are not made. This suggests that the wildtype (normal) form of the wpy gene is required (necessary) for normal muscle specification during development.

- How would you test the hypothesis that wpy is sufficient to specify muscle cell fate? Explain your answer.

-Suppose wpy encodes a transcription factor. Describe one approach for determining the gene targets of the wpy protein.