Read the assigned article by
Chen and Schier.
1. The authors injected sqt or cyc
RNA into single cells of Zebrafish embryos, and they assayed the activity of
the ligands using several markers, including ntl and bik. Describe the results depicted in Figs
1l, 1m, and 1n. What do the
authors conclude from these experiments?
2. Consider the experiments in Figure 4. The authors designed these experiments
to distinguish between two alternative hypotheses or models.
a) What are the alternative hypotheses being tested?
b) Describe the experimental design. In your answer, include an explanation
of why the authors used MZoep mutants.
Also, why did the authors transplant wild type cells ³at a distance²
from the injected cells?
c) What results were predicted by each of the hypotheses
being tested?