▁research ▁interest ▁because ▁it ▁can ▁be ▁used ▁to ▁transfer ▁DNA ▁from ▁one ▁b acter ial ▁cell ▁to ▁another ▁in ▁a ▁process ▁known ▁as ▁trans du ction . ▁ ▁As ▁it ▁rep licates ▁during ▁its ▁l yt ic ▁cycle ▁it ▁capt ures ▁fragments ▁of ▁the ▁host ▁chrom os ome . ▁ ▁If ▁the ▁resulting ▁vir al ▁particles ▁are ▁used ▁to ▁inf ect ▁a ▁different ▁host ▁the ▁captured ▁DNA ▁fragments ▁can ▁be ▁integrated ▁into ▁the ▁new ▁host ' s ▁gen ome . ▁ ▁This ▁method ▁of ▁in ▁v ivo ▁gen etic ▁engineering ▁was ▁widely ▁used ▁for ▁many ▁years ▁and ▁is ▁still ▁used ▁today , ▁though ▁to ▁a ▁less er ▁extent . ▁P 1 ▁can ▁also ▁be ▁used ▁to ▁create ▁the ▁P 1 - der ived ▁artificial ▁chrom os ome ▁cl oning ▁vector ▁which ▁can ▁carry ▁relatively ▁large ▁fragments ▁of ▁DNA . ▁ ▁P 1 ▁enc odes ▁a ▁site - specific ▁recom bin ase , ▁Cre , ▁that ▁is ▁widely ▁used ▁to ▁carry ▁out ▁cell - specific ▁or ▁time - specific ▁DNA ▁recom bin ation ▁by ▁fl ank ing ▁the ▁target ▁DNA ▁with ▁lo x P ▁sites ▁( see ▁Cre - L ox ▁recom bin ation ). ▁ ▁Mor ph ology ▁The ▁vir ion ▁is ▁similar ▁in ▁structure ▁to ▁the ▁T 4 ▁ph age ▁but ▁simpler . ▁It ▁has ▁an ▁ icos ah ed ral ▁head ▁containing ▁the ▁gen ome ▁attached ▁at ▁one ▁vertex ▁to ▁the ▁tail . ▁The ▁tail ▁has ▁a ▁t ube ▁surrounded ▁by ▁a ▁contract ile ▁she ath . ▁It ▁ends ▁in ▁a