MOLECULAR BIOLOGY – Basic Genetics

1. MOLECULAR BIOLOGY – Basic Genetics MOLECULAR BIOLOGY AND GENETICS tomas.dolezal@prf.jcu.cz • Genetic basis • DNA structure and genetic code • Cell division, replication and transcription • RNA processing • Regulation of gene expression • Translation, function of proteins • DNA variation – mutations and repair • Recombinant DNA • PCR, sequencing, genomics • Gene expression analysis • Protein analysis, proteomics

2. MOLECULAR BIOLOGY – Basic Genetics GENETIC BASIS OF LIFE

3. MOLECULAR BIOLOGY – Basic Genetics November 24th, 1859: CENTRAL PROPOSITION OF EVOLUTION All living forms origin in common ancestors, they can change and give rise to new species. Darwin Wallace 2 major concepts: 1. Closely related species share common ancestor 2. Natural selection is a mechanism for evolution

4. MOLECULAR BIOLOGY – Basic Genetics THEORY OF EVOLUTION new questions: • More progeny is born and some characters • (advantageous)are more likely to be passed • to the next generation. • HOW ARE THE CHARACTERS INHERITED? • There has to be variability in populations so that • the natural selection has the pool to select from. • WHAT IS THE SOURCE OF VARIABILITY?

5. MOLECULAR BIOLOGY – Basic Genetics Johann Gregor Mendel (*1822 - †1884) Augustinian monastery in Brno

6. MOLECULAR BIOLOGY – Basic Genetics Mendel picked 7 characters which existed in 2 forms: He made „true-breeding varieties“ all individuals present in one form or the other for number of generations

7. MOLECULAR BIOLOGY – Basic Genetics Anthers Pollen Carpel amputated anthers

8. MOLECULAR BIOLOGY – Basic Genetics P F2 F1

9. MOLECULAR BIOLOGY – Basic Genetics Mendel’s first experiment Mendel:5 4741 850

10. MOLECULAR BIOLOGY – Basic Genetics MAIN CONCEPT OF HEREDITY arising from Mendel’s work Mendel’sinterpretation of his results 1. Each form of a character is controlled by certain heritable factor 2. Obtained results are best explained by the existence of factors in pair 3. Each parent passes to progeny only one of its two factors for the character relationship between gene and allele CHARACTER = GENE FACTOR = ALLELE = certain form of character

11. MOLECULAR BIOLOGY – Basic Genetics DOMINANT and RECESSIVE factors (alleles) HOMOZYGOTES and HETEROZYGOTES GENOTYPE andPHENOTYPE 1:2:1 3:1 Random segregation of alleles

12. MOLECULAR BIOLOGY – Basic Genetics For Mendel genes were just a theoretical entity What is a physical essence of the inherited factors? How are they copied, transmitted and expressed?

13. MOLECULAR BIOLOGY – Basic Genetics Zell-substanz, Kern und Zelltheilung (1882) Walther Flemming

14. MOLECULAR BIOLOGY – Basic Genetics in agreement with Mendel’s observation about heredity INTEGRATION OF CYTOLOGY AND GENETICS - CYTOGENETICS • Chromosomes show specific forms and sizes • Number of chromosomes is characteristic for each species • In most plants and animals chromosomes were present in pairs 1902-1903four cytogeneticistsindependently formulated a concept: „Mendel’s laws of inheritance are direct consequences of organization and behavior of chromosomes“

15. MOLECULAR BIOLOGY – Basic Genetics PROBLEMS TO ACCEPT CHROMOSOME THEORY OF INHERITANCE It was obvious that there is more genes than chromosomes. How is then possible that the genes do not „travel“ with chromosomes? (Mendel was lucky to pick each factor on different chromosome) Nobody observed that a certain gene would travel from generation to generation together with certain chromosome.

16. MOLECULAR BIOLOGY – Basic Genetics Thomas Hunt Morgan (1866-1945) 1910 Drosophila melanogaster

17. MOLECULAR BIOLOGY – Basic Genetics P X YX X X F1 X Y X X X F2 YX Y X X X X X

18. MOLECULAR BIOLOGY – Basic Genetics white yellow miniature

19. MOLECULAR BIOLOGY – Basic Genetics FIRST SUMMARY – CRUCIAL KNOWLEDGE

20. MOLECULAR BIOLOGY – Basic Genetics cytoplasm Gene X in diploid cell nucleus Pair of homologous chromosomes, one from father, one from mother allele X1 allele X2 protein X1 protein X2

21. MOLECULAR BIOLOGY – Basic Genetics Somatic line Mitosis Genetic information is not mixed both progeny cells are genetically the same as the parental cell

22. MOLECULAR BIOLOGY – Basic Genetics grandmotherB grandfatherB grandfather A grandmother A MOTHER FATHER Recombination between pairs of homologous chromosomes from grandfather B from grandmother A from grandfather A from grandfather B

23. MOLECULAR BIOLOGY – Basic Genetics GENESARE ON CHROMOSOMES proteins DNA

24. MOLECULAR BIOLOGY – Basic Genetics Frederick Griffith (1871 - 1941)

25. MOLECULAR BIOLOGY – Basic Genetics 1928 – Griffith’s experiment TRANSFORMATION OF GENETIC MATERIAL

26. MOLECULAR BIOLOGY – Basic Genetics What was the transformation factor? 1944 Oswald T. Avery Colin M. MacLeod Maclyn McCarty Rockefeller Institute for Medical Research, New York

27. MOLECULAR BIOLOGY – Basic Genetics TRANSFORMATION FACTOR

28. MOLECULAR BIOLOGY – Basic Genetics Bacteriophage infectingE.coli

29. MOLECULAR BIOLOGY – Basic Genetics Martha Chase a Alfred Hershey - 1952

30. MOLECULAR BIOLOGY – Basic Genetics 35S 32P 32P 32P 32P 32P 35S DNA Methionin

31. MOLECULAR BIOLOGY – Basic Genetics Hershey-Chase experiment

32. MOLECULAR BIOLOGY – Basic Genetics