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DNA
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What is DNA
“DNA is deoxyribonucleic acid, a self-replicating material present in nearly all living organisms as the main constituent of chromosomes. It is the fundamental and distinctive characteristics of someone or something especially when regarded as unchangeable.” - Dictonary.com
Nearly every cell in a person’s body has the same DNA. Most of the DNA is found in the cell nucleus but a small amount of it can be found in the mitochondria. -
Gregor Mendel
He is also known as the father of genetics. He started the whole idea of “genetics” from an experiment he did with pea plants as they were easy to grow, he started cross-breeding the flowers in hopes of creating different genetic traits, he later discovered recessive genes and dominant genes and so the discovery of genetics began... -
Hugo deVries, Carl Correns, and Eric von Tschermak
Hugo deVries, Carl Correns, and Eric von Tschermak independently prove and confirm Mendel’s work. -
Thomas Hunt Morgan
Thomas Hunt Morgan show that genes are located along chromosomes. -
Fredrick Griffith
In an experiment with lab mice, Frederick Griffith transfers the component of a strain of pneumonia bacteria to an innocuous bacteria strain and comes to a conclusion that there must be a genetic “transforming factor” in the bacteria. -
Phoebus Levene
Phoebus Levene discovers that the sugar deoxyribose is present in nucleic acids and later prove that DNA is made up of nucleotides, which consist of a deoxyribose sugar, a phosphate group, and one of the four bases. -
Erwin Chargaff
Scientists were trying to make a model to understand how the DNA molecule worked and what its job was. Erwin Chargaff noticed a pattern in the amounts of the four bases: adenine, guanine, cytosine and thymine. Using samples of DNA of different cells he found that the amount of adenine was almost equal to the amount of thymine and that the amount og guanine was almost equal to the amount of cytosine. Therefore: A=T and G=C. This became Chargaff’s rule. -
Oswald Avery
Avery continued Griffith’s experiments to identify the inheritance molecule. He destroyed lipids, ribonucleic acids, carbohydrates, and proteins of the virulent pneumonia. Transformation still occurred. When he destroyed deoxyribonucleic acid, the transformation did not occur. He had found that the inheritance molecule was DNA. -
William Astbury
William Astbury takes first x-ray diffraction images of DNA. -
Oswald Avery, Colin MacLeod and Maclyn McCarty
Oswald Avery, Colin MacLeod and Maclyn McCarty show that DNA, and not protein is the “transforming factor” that Griffith first identified. -
Maurice Wilkins and Rosalind Franklin
Maurice Wilkins and Rosalind Franklin manage to take x-ray pictures of DNA crystals which will later lead Watson and Crick to their famous conclusion. -
Alfred Hershey and Martha Chase
Alfred Hershey and Martha Chase prove that viral DNA and not viral protein direct the replication of new viruses, proving that DNA is the molecule that mediates hereditary. -
James Watson and Francis Crick
James Watson and Francis Crick describe the structure of a DNA as a double helix: two spiralling strands held together by complementary base pairs. They later received a nobel prize for their work. However, they did this through the information that other people had previously presented and they simply pieced the puzzle together after all those years. -
Arthur Kornberg
Arthur Kornberg first synthesized DNA in a test tube which earned him a nobel prize while he was the head of the department of Microbiology in Washington University School of Medicine in St. Louis, sharing the nobel prize with Severo Ochoa, - Kornberg for synthesizing DNA, and Ochoa for RNA. -
Jerome Lejeune
Jerome Lejeune was a french pediatrician and geneticist, he was famous for discovering that Down’s syndrome is caused from an extra pair of chromosome in the 21st pair - winning a nobel prize. -
F. Sanger
Fredrick Sanger won 2 nobel prizes and was the only person to do so, he also developed the sequencing procedure for DNA, the sequence was later named after him - Sanger sequencing. -
Marshall Nirenberg
Genetic Code deciphered by Marshall Nirenberg with his colleague Johann H. Matthaei, now, scientists are able to predict characteristics from our genetics. -
Werner Arber
Scientist Werner Arber who is also a Swiss micro-biologist and geneticist, sharing a nobel prize isolates restriction enzymes. -
Paul Berg
Paul Berg American biochemist and a professor at Stanford University, employs restriction enzymes to cut and splice DNA creating the first strand of recombinant DNA. -
Genetic Engineering
First genetically engineered drug was invented - Humulin which is a kind of insulin grown in genetically modified bacteria is produced. -
Barbara McClintock
Barbara McClintock an american scientist and is one of the world's most famous cytogeneticists was awarded the Nobel Prize for her discovery that genes are able to change position on chromosomes. -
James Gusella
James Gusella, a canadian neurologist uses blood samples collected from Venezuela by Nancy Wexler to identify the Huntington’s disease marker. -
Kary Mullis
PCR, to date the most accurate and sensitive method for amplifying DNA, is developed by Kary Mullis. -
HGR
First discussions of initiating a Human Genome Project which is an international research project in order to determine the DNA sequence of an entire human genome. -
US Supreme Court allows genetically modified organisms to be patented.
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Francis Collins and Lap-Chee Tsui
Francis Collins and Lap-Chee Tsui identify the Cystic Fibrosis gene, which is an inherited genetic disorder that has been violently attacking the human lung. -
Gene Therapy
First successful gene therapy performed on a girl with an inherited immunodeficiency disorder. A girl had ADA which is a genetic disease that left her defenseless against infections. White blood cells were taken from her, and the normal genes for making ADA were inserted into them and the corrected cells were then reinjected into her. -
Huntington Disease
On Tuesday, March 23, 1993, scientists have found the genetic mutation that causes the fatal huntington disease. This genetic disorder usually attacks people between the age of 35 and 45, although symptoms can appear anytime. -
Cloning
Dolly the Sheep is the first mammal to be cloned. Dolly was cloned using the process of nuclear transfer. This process includes removing DNA from an unfertilized egg, and injecting the nucleus, which contains the DNA to be cloned. The newly structured cell will divide normally while replicating the new DNA. If the cells are placed in the uterus of a female mammal, a cloned organism develops. Dolly was born to three mothers. One provided the egg, another the DNA and another carried the cloned emb -
HGP
Announcement of a completed “working draft” DNA sequence of the human genome by the public project. The HGP public consortium has assembled a working draft of the sequence of the human genome - the genetic blueprint for a human being. This process involved two main things: placing large fragments of DNA in the proper order to cover all of the human chromosomes, and determining the DNA sequence of these fragments. -
HGP - final
Announcement of the final completion of the human genome sequence. This sequence closed the gaps from a working draft of the genome. It identified the locations of many human genes and provided information about their structure and organization. -
What impact has it made
- we started to understand inherited diseases (predicting + curing)
- DNA fingerprinting to solve crimes
- finding long lost family
- research on ancestry of humans
- movies and media on discovery
- proved that humans were not evolved from neanderthals
- proved Charles Darwin correct in his theory of human evolution
- started genetic engineering
- DNA vaccines
