Jeremiah 10:12

1. Jeremiah 10:12 12 He hath made the earth by his power, he hath established the world by his wisdom, and hath stretched out the heavens by his discretion.

2. Replicons Timothy G. Standish, Ph. D.

3. The Information Catch-22 “With only poor copying fidelity, a primitive system could carry little genetic information without L [the mutation rate] becoming unbearably large, and how a primitive system could then improve its fidelity and also evolve into a sexual system with crossover beggars the imagination.” Hoyle F. 1987. "Mathematics of Evolution", Acorn Enterprises: Memphis TN, 1999, p 20

4. The Cell Lifecycle • The cell lifecycle is well defined and can be divided into four stages: • Gap 1 (G1) - The growth phase in which most cells are found most of the time • Synthesis (S) - During which new DNA is synthesized • Gap 2 (G2) - No transcription or translation occurs and final preparations for division are made • Mitosis - Cell division • Once Synthesis is initiated, the cell is committed to division • Thus initiation of DNA replication is a carefully controlled process in cells

5. The Cell Lifecycle Gap 1 - Doubling of cell size. Regular cellular activities. Transcription and translation etc. Synthesis of DNA - Regular cell activities cease and a copy of all nuclear DNA is made S Gap 2 - Final preparation for division G1 G2 M Mitosis - Cell division

6. Stages of Replication • Replication can be divided into three stages: • Initiation - When DNA is initially split into two strands and polymerization of new DNA is started • Elongation - When DNA is polymerized • Termination - When the new strands of DNA are completed and some finishing touches may be put on the DNA • Both elongation and termination may involve proof reading of the DNA ensuring that mutations are not incorporated into newly formed DNA strands

7. Initiation • Initiation starts at specific DNA sequences called origins (Ori C = origin in E. coli chromosomes) • Long linear chromosomes have many origins • First the origin melts (splits into two single strands of DNA) • Next primers are added • Finally DNA polymerase recognizes the primers and starts to polymerize DNA 5’ to 3’ away from the primers

8. Initiation - Forming the Replication Eye Or Bubble Origin of Replication 5’ 3’ 3’ 5’ Replication eye or replication bubble 3’ 5’ 5’ 3’ 3’ 5’ 5’ 3’ 3’ 5’ 5’ 3’ 3’ 5’ 3’ 5’

9. Large Linear Chromosomes Have Many Origins Of Replication Origins of Replication 5’ 3’ 5’ 3’ 3’ 5’ 5’ 3’ 3’ 5’ 5’ 3’ 5’ 3’ 5’ 3’ 5’ 3’ 5’ 3’

10. Bacteria Have Circular Chromosomes Cell Wall Cell Membrane Cytoplasm Origin of Replication Chromosome Termination of Replication

11. Replication Replication goes in both directions Original Chromosome Start of replication Theta (q) structure Mid replication End of replication Two chromosomes

12. Binary Fission Revisited

13. Various Replication Strategies • D-loop • Rolling circle

14. 2 Conjugation F plasmid F- bacteria F plasmid F+ bacteria Mating Bridge

15. 2 Conjugation F plasmid F+ bacteria F- bacteria F plasmid Mating Bridge

16. 2 Conjugation F plasmid F+ bacteria F- bacteria F plasmid Mating Bridge

17. 2 Conjugation F plasmid F+ bacteria F- bacteria Mating Bridge F plasmid

18. 2 Conjugation F plasmid F+ bacteria F- bacteria Mating Bridge F plasmid F plasmid

19. Hfr Recombination F plasmid Integration Hfr cell F+ bacteria F- bacteria Transfer of genetic material

20. Hfr Recombination F plasmid Integration Hfr cell F+ bacteria F- bacteria Crossing over Interruption of conjugation Transfer of genetic material

21. Hfr Recombination F plasmid Integration Hfr cell F+ bacteria F- bacteria Recombinant Bacteria

22. The End