Yields of virus like {HEAD ~ particles} derived from {TAIL ~ those optimized HPV L1 genes} are high 
derived from
Yields of virus like { HEAD ~ particles } derived from { TAIL ~ those optimized HPV L1 genes } are high
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH