DNA Timeline
Category: Other
Updated: 14 Dec 2018
Contributors
Created by Devanshi Bhavsar
Attachments
Events
Friedrich Miescher (1869)
-identified "nuclein" (today's DNA)
in the nuclei of white blood cells of
humans
-this credit tends to wrongly be
given to Watson and Crick Oswald Avery, Colin MacLeod, Maclyn McCarty (1941)
-identified that DNA is the transforming principle by
building
on Griffith's mouse experiment
-injected purified versions of DNA and protein into mice
-DNA killed the mice, protein did not James Watson & Francis Crick (1953)
-developed the double helix model of
DNA based on data gathered by Rosalind
Franklin and Maurice Wilkins
-an accurate representation of DNA in modern times Rosalind Franklin & Maurice Wilkins (1952)
-investigated the structure of DNA using X-Ray
diffraction techniques
-photo 51 is a famous x-ray crystallography
image demonstrating a helical structure to DNA
-helped Watson and Crick construct an
accurate DNA model Gregor Mendel (1866)
-discovered the basic principles of genetics
with his pea plant experiments
-used the terms dominant and recessive
to explain his experimental results
-called his findings as "invisible" traits
(called genes today) Frederick Griffith (1928)
-came up with the "Transforming
Principle" that can change phenotype
by his experiment with mice
-the heat-killed virulent bacteria was able
to transmit the virus into the nonvirulent
bacteria Erwin Chargaff (1950)
Summarized major findings into...
Chargaff's Rules:
-adenine pairs with thymine
-guanine pairs with cytosine
-bases form weak hydrogen
bonds Alfred Hershey & Martha Chase (1952)
-conclusively confirmed that DNA is the
transforming factor
-"Blender Experiment"
-Protein(S) radioactively labeled--ends up
outside in the liquid
-DNA radioactively labeled--ends up inside
the pellet Phoebus Levene (1909)
-discovered the basic components
of nucleic acids
-figured how the components fit together,
including the nucleotides Linus Pauling (1952)
-came up with the
triple-stranded DNA
model(wrong)
-induced Watson and
Crick to come up with
the correct model Thomas Hunt Morgan (1908)
-discovered that chromosomes are
related to phenotype and also that
genes are on chromosomes, by his
work with fruit flies
-the male fruit flies with white eyes
had a specific X chromosome William Astbury (1943)
-developed X-Ray diffraction
patterns
-had developed an image
similar to Rosalind Franklin's
photo 51 before she did Werner Arber (1962)
-came up with the concept
of restriction and modification
enzymes, produced by bacteria,
being able to defend against
invading viruses
-based on experiments done
with lambda phages Paul Berg (1972)
-created the first
recombinant DNA
molecule
-new discoveries in
biochemistry helped
with this discovery
-individual genes could
now be isolated and
inserted into a cell Fred Sanger (1977)
-developed rapid sequencing
procedure for DNA
(Sanger Method)
-used to determine order
of bases in DNA strand Kary Mullis (1983)
-developed PCR
(Polymerase
Chain Reaction)--an easier
method of obtaining a specific
sequence of DNA
-used to identify
causative agents
to infections
-also used to screen
patients for genetic diseases Francis Collins (1989)
-found the cystic fibrosis gene
-used "positional cloning"
-allows the ability to identify
a disease gene without knowing
about the functional abnormality [CRISPR] Cas9 and PAM discovered (May 2005)
-discovery made by Alexander Bolotin while studying
the bacteria Streptococcus thermophilus
-(Cas9-protospacer adjacent motif) a novel cas gene
that encodes for a large protein predicted to have
nuclease activity
-(PAM) a sequence required for target recognition Celera Organization and US
Department of Energy (1990)
-created the Human Genome
Project to try to sequence the
entire human genome
-an international effort that
lasted into 2003 Marshall Nirenberg &
H. Gobind Khorana
(1968-year of Nobel Prize)
-Nirenberg discovered the first
triplet/codon
-codon: a sequence of three
bases that codes for one of
20 amino acids
-used test tube techniques
for experiments
-Khorana demonstrated the
role of nucleotides in protein
synthesis
-both cracked the genetic code George Garnow (1954)
-proposed that the genetic
code was determined by
triplets of nucleotides
-basic contribution to the
modern genetic theory Periods
History of DNA Timeline
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