▁during ▁double - str and ▁break ▁( D SB ) ▁repair ▁process ▁as ▁en vision ed ▁by ▁studying ▁b aker ' s ▁ye ast , ▁Sac char omy ces ▁C ere vis iae ; ▁and ▁termin ates ▁by ▁int ragen omic ▁dynamics ▁of ▁ampl ification , ▁mut ation , ▁or ▁delet ion , ▁which ▁also ▁known ▁as ▁post - insert ion ▁modifications . ▁The ▁mechanism ▁of ▁m t D NA ▁transfer ▁into ▁nucle us ▁has ▁not ▁yet ▁fully ▁understood . ▁ ▁Transfer ▁of ▁the ▁released ▁m t D NA ▁into ▁the ▁nucle us : ▁The ▁first ▁step ▁in ▁the ▁transfer ring ▁process ▁is ▁the ▁release ▁of ▁m t D NA ▁into ▁the ▁cy top las m . ▁Th ors ness ▁and ▁Fox ▁demonstrated ▁the ▁rate ▁of ▁re location ▁of ▁m t D NA ▁from ▁mit och ond ria ▁into ▁the ▁nucle us ▁using ▁u ra 3 - ▁ ▁ye ast ▁stra in ▁with ▁an ▁engine ered ▁U RA 3 ▁pl as mid , ▁required ▁gene ▁for ▁u rac il ▁b ios yn thesis , ▁in ▁the ▁mit och ond ria . ▁During ▁the ▁propag ation ▁of ▁such ▁ye ast ▁stra ins ▁carrying ▁a ▁nuclear ▁u ra 3 ▁ ▁mut ation , ▁pl as mid ▁DNA ▁that ▁esc apes ▁from ▁the ▁mit och ond r ion ▁to ▁the ▁nucle us , ▁comple ments ▁the ▁u rac il ▁b ios yn th etic ▁defect , ▁rest oring ▁growth ▁in ▁the ▁absence ▁of ▁u rac il , ▁and ▁easily ▁scored ▁phen ot ype . ▁The ▁rate