A restriction enzyme is used to insert a hummingbird gene into a plasmid, which acts as a cloning vector and placed back into E. coli cells.
The plasmid genes ampR (ampicillin resistance) and lacZ are used as genetic markers to screen for E. coli cells containing the recombinant gene of interest.
Once identified, the recombinant E. coli cells are cloned to make many copies of the gene of interest.