Test Hypothesis that a Gene Y is Important?

You just started working in a laboratory and one of your colleagues tells you that he hypothesizes that gene Y is important for transformation to a cancer phenotype (increase in cell proliferation). He gives you the sequence of the gene and a tube with genomic DNA and another tube with mRNA from human breast epithelial cells. He asks you if you can help him test his hypothesis.
a) He is not sure if one of the tubes he gave you is the one with the human breast epithelial cell DNA. How can you make sure that the tube has the correct DNA (i.e. gene Y is within the pool of DNA he gave you?
b) How can you clone gene Y from the material he gave you?
c) How can you test the function of gene Y (i.e. if it promotes cell proliferation)?

Since the tubes are not labeled and the colleague is not sure which one is which, we can use the given sequence of the gene Y to design a probe that’s complementary to it and hybridize it using Southern blot (DNA digested by restriction endonucleases, fragments separated by electrophoresis and then transferred to a membrane for hybridization).

In order to clone gene Y from the given material, we can either use the mRNA and do a Reverse Transcription to synthesize the DNA or just directly use the DNA sample that we found above to include gene Y. We then use restriction enzymes to fragment the cDNA or DNA and the vector we’ll use to insert the fragments in. Then we can transform bacteria with these vectors, cell culture them resulting in many copies-clones (that we can screen for) of gene Y.

Test the function of gene Y : (cell proliferation)
The vector gene Y will be isolated from the above transformed bacteria and used to transfect cells that will be cultured under appropriate conditions and compare them to cells that were not transfected with that gene. If an increased number of cells/colonies is observed of the transfected cells in relation to a lower or limited number of the other cells then gene Y does promote cell proliferation .