The Story of DNA

--- History of Molecular Biology

“History Teaches Everything, Including the Future.”--- Alphonse de Lamartine

Genetics

Biochemistry

Cell biology

Microbiology

Virology

…

1929 – the chemical components of DNA 1940 – the relationship between genes and proteins 1944 – Genes are made up of DNA

1953 – the double helical structure of the DNA molecule (Watson and Crick) 1957 – the “Central Dogma” and the “sequence hypothesis” (Crick)

1958 – the mechanism of DNA replication 1961 – the hypothesis of the messenger RNA (mRNA) 1961 to 1965 – the genetic code was deciphered ……

1970s to 80s – DNA cloning, sequencing and genetic engineering 1990s to 2000s – genome sequencing and functional study of genes

Overview of the History of Molecular Biology

1930 1940 1950 1960 1970 1980 1990 2000

Genes and DNA

DNA - RNA - protein

DNA cloning and genetic

engineering Genome eraDiscovery of

DNA

Overview of the History of Molecular Biology

• The discovery of DNA- Hofmeister (1848): discovery of chromosome

s- Miescher (1868): “nuclein” = DNA + protein

• Chromosome theory of inheritance- Mendel (1865): Laws of inheritance- Morgan (1910): Genes are on chromosomes

• Who carries genetic material, DNA or proteins?

The search of genetic material

1930 1940 1950 1960 1970 1980 1990 2000

Genes and DNA

DNA - RNA - proteinDNA cloning and

genetic engineering Genome eraDiscovery of

DNA

How did people know that DNA carries genetic information?

Avery, Macleod and McCarty’s experiment (1943)

http://www.dnaftb.org/dnaftb/17/animation/animation.html

1930 1940 1950 1960 1970 1980 1990 2000

Genes and DNA

DNA - RNA - proteinDNA cloning and

genetic engineering Genome eraDiscovery of

DNA

• A) What was the original observation that Avery made in test tubes?

• B) List two hypotheses based on the observation (doesn’t matter if they are right or wrong).

• C) What predictions would you make based on each of the hypotheses?

Avery’s Experiment on Pneumococcus:

How did people know that DNA carries genetic information?

Avery, Macleod and McCarty’s experiment (1943)

http://www.dnaftb.org/dnaftb/17/animation/animation.html

1930 1940 1950 1960 1970 1980 1990 2000

Genes and DNA

DNA - RNA - proteinDNA cloning and

genetic engineering Genome eraDiscovery of

DNA

The Double Helix

Watson Crick Wilkin Franklin

Crick and Watson: theoretical model

Wilkins and Franklin: X-ray diffraction

First accurate model of DNA's molecular structure (1953)

Nobel Prize, 1962

"Why You Are You. Nearer Secret of Life." --The News Chronicle of London

1930 1940 1950 1960 1970 1980 1990 2000

Genes and DNA

DNA - RNA - proteinDNA cloning and

genetic engineering Genome eraDiscovery of

DNA

Rosalind Franklin: The Dark Lady of DNA

Rosalind Franklin (1920-1958)

A British Biophysicist

Specialized in X-ray crystallography

King’s College, London (1951-1953):

- Worked with Maurice Wilkin and Raymond Gosling

Form A and B of DNA

Photograph 51

”The Eighth Day of Creation: Makers of the Revolution in Biology“ by Horace Freeland Judson

1957 – the “Central Dogma” (Crick)

1958 – the mechanism of DNA replication

1961 – the hypothesis of the messenger RNA

1961 to 1965 – the genetic code was deciphered

From DNA to Proteins

Howard Temin (Nobel Prize 1975)

Reverse transcriptase

1930 1940 1950 1960 1970 1980 1990 2000

Genes and DNA

DNA - RNA - proteinDNA cloning and

genetic engineering Genome eraDiscovery of

DNA

The Golden Age of Molecular Biology

1969: First gene in bacterial DNA isolated 1970: First synthetic (artificial) gene

1973: First successful DNA cloning experiment

1977: DNA is sequenced

1978: The first human gene is cloned – insulin 1982: Genetically-engineered insulin is approved for use

1985: PCR (Polymerase Chain Reaction) is invented

Har Gobind Khorana(Nobel Prize 1968)

1930 1940 1950 1960 1970 1980 1990 2000

Genes and DNA

DNA - RNA - proteinDNA cloning and

genetic engineering Genome eraDiscovery of

DNA

The Golden Age of Molecular Biology

1996: First genome sequenced – S. cerevisae (yeast) 1997: Bacteria E. coli genome sequenced 1998: C. elegans (worm) sequenced 2000: Drosophila (fruit fly) sequenced 2002: Mouse sequenced

2001: First draft sequences of the human genome are released (Human Genome Project)

2003: Completion of the mapping of the genes in the human genome

Fred Blattner

1930 1940 1950 1960 1970 1980 1990 2000

Genes and DNA

DNA - RNA - proteinDNA cloning and

genetic engineering Genome eraDiscovery of

DNA

What can we do with DNA?

Genetic engineering - Use model organisms to study

genes and functions - Make transgenic organisms

Applications for human - Forensics, paternity testing - Genetic diagnosis and prevention of diseases (Ge

netic counseling) - Gene therapy …

DNA and The Revolution in Personalized Medicine

Your life depends on the secret of your DNA…

Personalized Medicine - Genetic screening for prevention (newborn

screening, carrier screening, maternal screening, Pre-implantation Genetic Diagnosis (PGD))

- Risk prediction - The right drug at the right dose for the rig

ht person

Fields Related to Modern Molecular biology

Bioinformatics

Biophysics and Structural Biology

Population and evolutionary biology

Molecular genetics

Genomics

Cell Biology

Developmental Biology

Next class:

Case Study: The Human Genome Project and Designer Baby

Discussion of Molecular biology research groups on campus – What

do they do and why?