▁direct ▁physical ▁connection ▁and ▁memb rane ▁fusion ▁between ▁mit och ond ria ▁and ▁nucle us , ▁and ▁enc aps ulation ▁of ▁mit och ond rial ▁compart ments ▁inside ▁the ▁nucle us , ▁as ▁shown ▁in ▁figure ▁ 1 . ▁ ▁Pre - insert ion ▁prepar ation : ▁ ▁After ▁reaching ▁the ▁nucle us , ▁m t D NA ▁has ▁to ▁enter ▁the ▁nuclear ▁gen ome . ▁The ▁rate ▁of ▁m t D NA ▁incorpor ation ▁into ▁the ▁nuclear ▁gen ome ▁can ▁be ▁expected ▁to ▁depend ▁on ▁the ▁D SB ▁number ▁in ▁n D NA , ▁the ▁activity ▁of ▁D SB ▁repair ▁systems , ▁and ▁the ▁rate ▁of ▁m t D NA ▁escape ▁from ▁organ elles . ▁M t D NA ▁insert ion ▁compr ises ▁three ▁main ▁processes , ▁shown ▁in ▁figure ▁ 2 ; ▁first , ▁the ▁m t D NA ▁has ▁to ▁have ▁the ▁proper ▁form ▁and ▁sequence ; ▁in ▁other ▁words , ▁the ▁m t D NA ▁has ▁to ▁be ▁edited ▁which ▁gives ▁a ▁rise ▁to ▁the ▁new ▁edited ▁site ▁in ▁the ▁pol yn uc le ot ide ▁structure . ▁M ito ch ond rial ▁DNA ▁is ▁not ▁universal ▁and , ▁in ▁animals ▁similar ▁to ▁plants , ▁mit och ond rial ▁editing ▁shows ▁very ▁err atic ▁patterns ▁of ▁tax on - specific ▁occurrence . ▁As ▁shown ▁in ▁figure ▁ 2 , ▁there ▁are ▁three ▁possible ▁ways ▁that ▁m t D NA ▁can ▁become ▁prepared ▁to ▁be ▁inserted ▁into ▁the ▁nuclear ▁DNA . ▁The ▁process ▁mainly ▁depends ▁on ▁the ▁time ▁m t