Medicine is transforming rapidly. During this era of human history, scientists are forever changing lives, because for the first time humans are not powerless against their genes! We now have the power to not only predict, but also alter our very future. The Genetic Revolution is here!
With the power of gene therapy, scientists now have a new tool that enables them to change a patient's DNA. Medical treatments usually counteract the symptoms of a disease. But with gene therapy, doctors can cure diseases. Click to learn more
The concepts described in this website might be a review for some people, or it might be a new learning experience. Click in order to learn or review the basics of biology and genetics.
Medicine is transforming rapidly. During this era of human history, scientists are forever changing lives, because for the first time humans are not powerless against their genes! We now have the power to not only predict, but also alter our very future. The Genetic Revolution is here!
A General History of Genetics, DNA, and Biotechnology
All of the great medical and scientific technologies....
we have and use presently didn't appear out of nowhere, they were created by great scientists who collaborated and built upon each other's research. Thanks to these people, we can engineer antibodies, decode DNA, genetically modify plants, and much more.
This page will show the steps that were taken, the experiments performed, and the research conducted to give us
The Genetic Revolution
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Gregor Mendel, also known as the Father of Genetics, was a monk of the Roman Catholic Church who also studied at the University of Vienna. For eight years he grew thousands of pea plants, studying hereditary and inheritance. Mendel published his paper in 1866, but it took 34 years until his genius was recognized.
Friedrich Miescher found a substance that only existed in the chromosomes, and called it "nuclein" in 1869. He isolated a pure sample of this substance (DNA) from the sperm salmon, and his pupil, Richard Altmann, named it "nucleic acid" in 1889.
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Archibald Garrod, a British physician, hypothesized that genes are involved in creating proteins fundamentally important in metabolism.
Microscope studies of DNA and protein showed that both substances are present in chromosomes.
Frederick Griffith was working on a project which formed the basic idea that DNA was the molecule of inheritance. Using mice, he strategically injected virulent pneumonia and nonvirulent pneumonia into his specimens. He noticed that the non-virulent bacteria inherited characteristics of virulent bacteria and called this process transformation.
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A diagram showing Frederick Griffith's experiment (30)
Phoebus Levene identified the components making up a DNA molecule:
The bases Adenine, Cytosine, Guanine, and Thymine; the sugar, and the phosphate. He showed that DNA was made of components linked in a phosphate-sugar-base order.
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George Beadle and Edward Tatum supports the hypothesis of Archibald Garrod. Their evidences will help with the "one gene on proteinH hypothesis", which explains that each protein in a cell results from the expression of a single gene.
On the left is George Beadle, and on the right is Edward Tatum
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Conrad Hal Waddington proposed the term epigenetic, for describing phenotype resulting from external rather then genetic influences.
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Oswald T. Avery wanted to know the identity of the inheritance molecule. He noticed that after destroying lipids, ribonucleic acids, proteins, and carbohydrates of the virulent pneumonia, transformation still occured. Using a deoxyribonucleic acid-destroying-enzyme, Oswald discovered that transformation did not occur anymore. He concluded that DNA was the basis of inheritances.
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Biochemist Erwin Chargaff concluded that the amount of DNA and its nitrogenous bases varied from species to species. He also discovered that the amount of Adenine equals Thymine, and the amount of Cytosine equals Guanine in the DNA of every species.
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Alfred Hershey and Martha Chase worked with small bacteria-infecting viruses called phrages. They infected the bacteria with viruses with either radioactively labeled proteins, or radioactively labeled DNA. Bacteria infected with the DNA became radioactive, giving more support to the idea that DNA is the molecule of heredity.
Sidney Brenner and Francis Crick determined that groups of three nucleotide bases, called codons, are used to determine individual amino acids.
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On the left is Brenner and on the right is Crick
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Francis Crick, James Watson, and Maurice Wilkins determined the molecular structure of DNA, receiving the Nobel Prize.
The genetic code for amino acids are determined, allowing biochemical analysis to figure out which codons code for which amino acids.
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Hamilton Smith isolated the first restriction enzyme, a molecule used to cut DNA at specific nucleotide sequence.
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Stanley Cohen and Herbert Boyer created recombinant DNA, beginning the biotechnology industry.
On the left is Cohen and on the right is Boyer (42) (43)
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Frederick Sanger developed the "chain termination" method of DNA sequencing. This enabled scientists to figure out the exact number of A's, T's, C's, and G's in specific pieces of DNA.
Also during this year, Riggs and Holliday independently hypothesized that the chemical modifications of DNA could influence gene expression, beginning the idea of gene therapy.
Human hormone somatostatin, human insulin, and human growth hormones were first developed by Genentech scientists. Since then molecular biologists have produced many drugs by utilizing genetic tricks.
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Dr. Martin Cline conducted an unauthorized gene therapy procedure when he transferred rDNA into the bone marrow cells of two patients with genetic blood disorders.
DNA profiling was developed by English geneticist Alec Jeffreys of the University of Leicester. It was first used to convict Colin Pitchfork in the Enderby murders case in Leicestershire, England.
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Kary B. Mullis, a biochemist, published the first paper on polymerase chain reaction (PCR), a chemical reaction that can makes copies of even small amounts of DNA. It has been extensively used in genetic cloning, forensic analysis, and various genetic testings.
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Human gene therapy was conducted on four year-old Ashanti Desilva. She suffered from ADA deficiency, but the therapy (performed by Dr. W. French Anderson) corrected her immunodeficiency. Although it wasn't a complete cure, it helped correct the disorder so that Ashanti would only need small doses of the original PEG-ADA drug.
California biotech company, Calgene, Inc., produced the first commercially grown
genetically engineered food to be granted a license from the FDA. It contained genes that made it resistant to rotting.
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Dolly the sheep, the first mammal cloned from the cells of an adult animal, was born in Scotland at the Roslin Institute.
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On September 1999, Jesse Gelsinger, an 18 year-old boy, died from multiple organ failure thought to be a result of a severe immune response caused by a vector used for gene therapy. He suffered from OTC disease, a disorder of the liver which builds up poisonous levels of ammonia in the body. Hoping to help others with the same disease, he chosed to participate in the gene therapy experiment, despite the fact that his disorder was being controlled through medication and diet.
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French doctors successfully used gene therapy to completely cure 10 children of the immunodeficiency disease (X-SCID), sometimes called the "Bubble Boy" syndrome. Unfortunately, two of the 10 children developed leukemia after the treatment.
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