culturing a host transformed by a vector comprising {TAIL ~ a DNA segment} having {HEAD ~ the following nucleotide sequence}: 
culturing a host transformed by a vector comprising { TAIL ~ a DNA segment } having { HEAD ~ the following nucleotide sequence } :
OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH