▁and ▁the ▁tum or ▁cells ▁of ▁m ice ▁and ▁r ats , ▁which ▁proved ▁that ▁the ▁m t D NA ▁sequences ▁are ▁far ▁more ▁numerous ▁and ▁abund ant ▁in ▁n D NA ▁of ▁rod ent ▁tum or ▁cells ▁in ▁comparison ▁with ▁normal ▁cells . ▁Using ▁F IS H ▁prob es , ▁PC R ▁and ▁data ▁sequ encing , ▁mapping ▁and ▁comparison , ▁Ju ▁and ▁his ▁team mate ▁found ▁that ▁the ▁mit och ond rial - n uc lear ▁gen ome ▁fus ions ▁occur ▁at ▁a ▁similar ▁rate ▁per ▁base ▁pair ▁of ▁DNA ▁as ▁inter chrom os om al ▁nuclear ▁re arr ang ements , ▁indicating ▁the ▁presence ▁of ▁a ▁high ▁frequency ▁of ▁contact ▁between ▁mit och ond rial ▁and ▁nuclear ▁DNA ▁in ▁some ▁som atic ▁cells . ▁Also , ▁Ju ▁and ▁his ▁team m ates ▁investig ated ▁the ▁timing ▁of ▁som atic ▁m t D NA ▁integration ▁into ▁the ▁nuclear ▁gen ome ▁by ▁assess ing ▁cases ▁in ▁which ▁a ▁met ast atic ▁sample ▁had ▁been ▁sequ enced ▁in ▁addition ▁to ▁the ▁primary ▁tum or . ▁In ▁some ▁cases , ▁m t D NA ▁trans fers ▁into ▁the ▁nucle us ▁in ▁som atic ▁cells ▁are ▁very ▁frequent ▁and ▁can ▁occur ▁after ▁ne op last ic ▁formation ▁and ▁during ▁the ▁course ▁of ▁sub cl onal ▁evolution ▁of ▁cancer ▁which ▁suggest ▁that ▁this ▁event ▁occurs ▁in ▁the ▁common ▁ancest ral ▁cancer ▁cl ones ▁or ▁in ▁normal ▁som atic ▁cells ▁prior ▁to ▁the ▁ne op last ic ▁change . ▁These ▁find ings ▁demonstrated ▁that ▁the ▁presence ▁of