Question attached as a file
NOTE ON PROPOSED EXPERIMENTS:DO NOT SIMPLY NAME A METHOD. PROVIDE SUFFICIENT EXPLANATION THAT WE KNOW YOU UNDERSTAND HOW THE METHOD WORKS (AND REMEMBER DR. NAGY DOES NOT THINK THAT “TAG IT WITH GFP” IS A SUFFICIENT ANSWER TO ANY QUESTION).
SA1 (26 pts) In classic “transplant” experiments, the future neural plate (nervous system) of a frog embryo was moved from its usual dorsal position to the ventral region of a host embryo. The host and donor embryos were either at the early gastrula or late gastrula stage when the transplant was performed.
When the future neural plate of an early gastrula donor is transplanted, it develops as non-neural tissue (epidermis) on the ventral side of the host. However, when the future neural plate of a late gastrula donor is transplanted, it develops as a second neural plate on the ventral side of the host, as diagrammed below.
a. (5pts) In order to have performed this experiment, you need to know which piece of tissue is going to give rise to the normal neural plate. How would you determine this? What type of evidence does this kind of experiment provide?
b. (3pts)The neural plate is ____________ in the early gastrula stage. By the late gastrula stage, the
neural plate is _______________.
In the questions below, you can assume that all the methods we have studied work in frogs (even though some of you may realize they are not all feasible in frogs) (Remember: naming the method to use is not sufficient for full points)
c. The transcription factor NeuroD is expressed in late gastrula neural plate.
bi. (5pts) Describe a loss of function experiment to test function of NeuroD in neural plate formation (lose it)
bii (3pts) Describe a result consistent with this function.
biii (3pts) Describe a result inconsistent with this function.
c (5pts)Describe a gain of function experiment to test function of NeuroD in neural plate formation (move it)
ci (2pts) Describe a result consistent with this function.
cii (2pts) Describe a result inconsistent with this function.
