nnnnnAV解链复制完成十A2SMM第2代第1代→+→+++子亲亲代亲子代单链亲子子亲亲子子亲代代单代双链2单单DNA链链链半保留复制(semi-conservationreplication)
半保留复制 (semi-conservation replication) 亲代 双链 DNA 亲 代 单 链 子 代 单 链 亲 代 单 链 子 代 单 链 亲 子 子 亲 亲 子 子 亲 第1代 第2代 + + + + 解链 复制 完成 +
OK!template3Howtemplate
3’ 5’ OK ! How ? 5’ 3’ 5’ 3’ template template
a) Okazaki fragment1968ReijiOkazakiE.coli [t]2s,7s,15s,60s20℃ in dT-H3 30spulse-labeling in dT-H3pulse-chasestop inKCN 0℃transferto dT then continueD.S. DNAS.S. DNADensitygradient of sucroseMeasureH3-T
a) Okazaki fragment 1968 Reiji Okazaki E.coli [t - ] 2s, 7s, 15s, 60s pulse-labeling in dT-H3 stop in KCN 0℃ D.S. DNA S.S. DNA Density gradient of sucrose Measure H3 -T pulse-chase 20℃ in dT-H3 30s transfer to dT then continue
H3-TH3-Tpulse-chaseLDNApulse-labelingptttse-chase1O0120pulse-labeling60"N40S10s (1kb)Prok.40S10S (1kb)400Nt/sec10S40SDNAreplication in Okazakifragment1kb
H3 -T pulse-labeling pulse-chase 120’’ 60’’ 15’’ 7’’ 2’’ 10S (1kb) 40S Prok. 400Nt/sec DNA replication in Okazaki fragment 1kb 10S 40S
DNAreplicationinOkazakifragmentlkb(semi-discontinuousreplication!)At least one strand of DNA replication inOkazakifragment1kb
At least one strand of DNA replication in Okazaki fragment 1kb 5’ 3’ 5’ 3’ DNA replication in Okazaki fragment 1kb 5’ 3’ 5’ 3’ (semi-discontinuous replication ! ) ?