A forward genetics approach was successfully used to identif

A forward genetics approach was successfully used to identify fruit flies mutants that are overly sensitive to ethanol. One gene identified in this screen was named \"cheapdate\", which was subsequently mapped, cloned, and sequenced. Subsequent research indentified numerous mRNAs that were produced from this gene.

a. Describe a method that could be used to identify the 5` transcription start site for the gene

b. Describe a method that could be used to determine what other proteins the \"cheapdate\" protein product interacts with either in vivo or in vitro

c. A homologous gene for \"cheapdate\" was found when the mouse genome was sequenced. Describe a method whereby a mouse could be generated that is no longer able to produce any functional proteins from either of its \"cheapdate\" gene homologs.

Solution

A. 5\' transcription start site can be identified by mapping a nucleotide to which a 5\' cap structure has been added in the RNA.

B. Yeast two hybrid, Biomolecular fluorescece complementation assay are the few techniques using which we can detect the interactional behavior of the two proteins.

C. Methylating the gene can inactivate it and is is not able to form any functional protein. Apart from it mutations such as transition, transversion, deletion etc can be made which result in stoppage of the production of functional proteins.