Electroporation is a technique wherein cells are shocked with a slight amount of electricity, which causes the cells to make their membranes porous. At the same time, cells are exposed to loops of the DNA made by researchers. During the brief moment that the cells are porous, they are able to scoop up and internalize the loops of DNA. Transcription and translation of the DNA can then occur in the cells. Bruno is a graduate student who wants to find out how WNT signaling impacts fin development in zebrafish embryos. It is known that Wht gene mRNA is expressed in the developing fin, but it is unknown if it is required for fin development. Bruno knows that Dkk protein inhibits WNT signaling. Therefore, to investigate his question, Bruno carries out an experiment where he electroporates a loop of DNA containing the sequence for Dkk into a zebrafish embryonic trunk just prior to limb development, assuming that Dkk will be translated into protein in those cells and inhibit WNT signaling. Following the electroporation, Bruno observes the development of the embryos.
What type of experiment was this?
a. A gain-of-function experiment
b. A loss-of-function experiment