5222.化学诱变 a)干扰碱基合成的化学诱变剂 5-Amino uracil 6-Mercalto purine SH 干扰嘧啶合成 干扰嘌呤合成
5.2.2.2. 化学诱变 a) 干扰碱基合成的化学诱变剂 6-Mercalto purine 干扰嘌呤合成 SH 5-Amino Uracil 干扰嘧啶合成 O O H2N
b base analogy leads base mispairing Replication error G(k A(a) G(k) A(a) 5-BrU(k) C(a) 5-BrU(e) T(k) mispairing Incorporation error G(k) A(a A(a G(k 5-Bru(e) 5-BrU(k) T(k) C(e) mispairing
A(a) T(k) 5-BrU(k) G(k) 5-BrU(e) C(a) mispairing mispairing T(k) A(a) G(k) 5-BrU(k) C(e) 5-BrU(e) A(a) G(k) G(k) A(a) ➢ Replication error ➢ Incorporation error b) base analogys leads base mispairing
c) Base modifying-chemical mutagen > hNO2 (Nitrous acid NA) A HNO2 I次黄嘌呤 deamination U尿嘧啶 G :黄嘌呤 NH2OH (Hydroxylamine HA) HA C(a) C(h=A(a)
➢ HNO2 (Nitrous acid NA) c) Base modifying chemical mutagen A C G HNO2 deamination I C U A X C I:次黄嘌呤 U:尿嘧啶 X:黄嘌呤 ➢ NH2OH (Hydroxylamine HA) C(a) C(h) A(a) HA
d) Alkylation agent mutagens EMS(Ethyl methane sulfonate)CH3S-O--CH2CH3 MMS CH3S-O--CH3 SM( Sulfur Mustards gas硫芥子气)HS、CH2CH2CI CHCHCI
d) Alkylation agent mutagens ➢ EMS (Ethyl methane sulfonate) CH3—S—O--CH2CH3 O O ➢ MMS CH3—S—O--CH3 O O ➢ SM (Sulfur Mustards gas 硫芥子气) HS CH2CH2Cl CH2CH2Cl
e)Mutagen--insertion--framshift AO (Acridine orange) 扁平分子 EB (Ethidium Bromide) TAOT TTTCG ATTTTTCG-AOI-T AAAGC、~~ ATTTCG- TAAAGC TAAAAAGO EB L-AT EBTTTTCG ATXTTTTCG TA X AAAAGC-TAX AAAAGC
e) Mutagen—insertion--framshift AO (Acridine Orange) 扁平分子 EB (Ethidium Bromide) -ATTTTTCG - -TAAAAAGC- -A TTTCG - -T AAAGCTAO T -AT EB TTTTCG- -TA AO EB -ATTTCG - -TAAAGC- -ATX’TTTTCGX AAAAGC -TAX AAAAGC- -