Chapter 17, Problem 17P

A transcription factor Pax6 is required continually during the life of a mouse (or a human) for the development and maintenance of the retina. Homozygous Pax6 knockout mice die soon after birth because Pax6 protein is also required in essential organs, example the pancreas.

a.	In order to study the role of Pax6 in eye development, a researcher wants to generate a mouse that expresses Pax6 everywhere except in its eyes. Describe how you could construct such a mouse.
b.	Suppose the scientist wants to study the role of Pax6 in the adult eye. To do this, she wants mice that express Pax6 normally during development, but then she wants to remove Pax6 gene function from mice of different ages (one day old, two days old, etc.) and observe the effects. Describe a mouse strain that would enable her to perform this experiment. (Hint: Use the hs-cre transgene described in Problem 16.)
c.	Suppose the scientist in part (b) wants to create a mouse in which the only cells that express GFP are the eye cells from which Pax6 function has been removed. Marking the cells in this way will allow the investigator to see the shapes of the Pax6 eye cells more easily than if they did not express GFP. Diagram a Pax6 gene construct that would enable her to do this experiment