MOLECULAR BIOLOGY – Basic Genetics MOLECULAR BIOLOGY AND GENETICS 1.Genetic basis 2.DNA structure and genetic code 3.Cell division, replication and transcription 4.RNA processing 5.Regulation of gene expression 6.Translation, function of proteins 7.DNA variation – mutations and repair 8.Recombinant DNA 9.PCR, sequencing, genomics 10.Gene expression analysis 11.Protein analysis, proteomics

MOLECULAR BIOLOGY – Basic Genetics GENETIC BASIS OF LIFE

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

MOLECULAR BIOLOGY – Basic Genetics new questions: 1.More progeny is born and some characters (advantageous) are more likely to be passed to the next generation. HOW ARE THE CHARACTERS INHERITED? 2.There has to be variability in populations so that the natural selection has the pool to select from. WHAT IS THE SOURCE OF VARIABILITY ? THEORY OF EVOLUTION

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

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

Carpel Anthers MOLECULAR BIOLOGY – Basic Genetics Pollen amputated anthers

F1 F2 P MOLECULAR BIOLOGY – Basic Genetics

Mendel: MOLECULAR BIOLOGY – Basic Genetics Mendel’s first experiment

Mendel’s interpretation 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 MAIN CONCEPT OF HEREDITY arising from Mendel’s work relationship between gene and allele CHARACTER = GENE FACTOR = ALLELE = certain form of character MOLECULAR BIOLOGY – Basic Genetics

DOMINANT and RECESSIVE factors (alleles) HOMOZYGOTES and HETEROZYGOTES GENOTYPE and PHENOTYPE 1:2:1 3:1 Random segregation of alleles 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?

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

1.Chromosomes show specific forms and sizes 2.Number of chromosomes is characteristic for each species 3.In most plants and animals chromosomes were present in pairs in agreement with Mendel’s observation about heredity INTEGRATION OF CYTOLOGY AND GENETICS - CYTOGENETICS four cytogeneticists independently formulated a concept: „Mendel’s laws of inheritance are direct consequences of organization and behavior of chromosomes“ 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. MOLECULAR BIOLOGY – Basic Genetics

Thomas Hunt Morgan ( ) Drosophila melanogaster 1910 MOLECULAR BIOLOGY – Basic Genetics

X X P F1F1 F2F2 X Y XY X Y XX Y XY XY X MOLECULAR BIOLOGY – Basic Genetics

yellow white miniature MOLECULAR BIOLOGY – Basic Genetics

FIRST SUMMARY – CRUCIAL KNOWLEDGE

allele X1allele X2 protein X1protein X2 nucleus cytoplasm Gene X in diploid cell Pair of homologous chromosomes, one from father, one from mother MOLECULAR BIOLOGY – Basic Genetics

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

grandfather A grandmother A MOTHERFATHER from grandfather B from grandfather A from grandmother A Recombination between pairs of homologous chromosomes MOLECULAR BIOLOGY – Basic Genetics grandfather Bgrandmother B

GENES ARE ON CHROMOSOMES proteins DNA MOLECULAR BIOLOGY – Basic Genetics

Frederick Griffith ( ) MOLECULAR BIOLOGY – Basic Genetics

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

Oswald T. AveryColin M. MacLeodMaclyn McCarty 1944 What was the transformation factor? Rockefeller Institute for Medical Research, New York MOLECULAR BIOLOGY – Basic Genetics

TRANSFORMATION FACTOR MOLECULAR BIOLOGY – Basic Genetics

Bacteriophage infecting E.coli MOLECULAR BIOLOGY – Basic Genetics

Martha Chase a Alfred Hershey MOLECULAR BIOLOGY – Basic Genetics

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

Hershey-Chase experiment MOLECULAR BIOLOGY – Basic Genetics