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DNA history

Timeline created by NarrowArtist147 in Science and Technology
Event Date: Event Title: Event Description:
C small square Watson and Crick discover the shape of DNA After James Watson and Francis Crick saw the DNA pictures taken by Rosalind Franklin, they tried several different models until they finally realized that DNA is in the form of a double helix with two strands of nucleotides.
Jht small square 46 Chromosomes in Humans is Discovered Joe Hin Tjio, a NIH (National Institution of Health) researcher, discovered the actual number of chromosomes in humans was 46. He published his findings sometime in April 1956.
Polymerase small square DNA Polymerase Arthur Kornberg isolates DNA polymerase, an enzyme that will be used for many kinds of recombinant DNA techniques and sequencing. (year 1955, actual month and day not known)
Timeline small square Joe Hin Tjio Publishes findings on 46 Chromosomes
Semiconservative stuff small square Semiconservative Replication of DNA Matthew Meselson and Franklin Stahl discover that DNA replicates semiconservatively, each strand of DNA molecule from the parent generation pairing with a strand from the daughter generation. (actual date not known)
Mrna small square mRNA Function is Discovered Sydney Brenner, Francois Jacob, and Matthew Meselson discover that mRNA is the molecule that delivers information from DNA to the ribosomes in the cytoplasm. (actual date not known)
Genetic code cracking small square Interpretation of Genetic Code After several years, Marshall Nirenberg, Har Khorana and Severo Ochoa had finally cracked the genetic code. Showing how nucleic acids (and their four-letter alphabet) determine the order of the twenty kinds of amino acids in proteins.
Enzyme small square First Restriction Enzymes Described Several groups of researchers discovered that restriction enzymes recognize and cut specific short sequences of DNA. They’re found in bacteria, which use the enzymes to digest invading DNA. The enzymes became an important, early tool for mapping genomes. (actual date not known)
Recombinant dna small square The First Recombinant DNA The first production of recombinant DNA molecules, using restriction enzymes. Recombinant DNA technology involves the joining of DNA from different species and subsequently inserting the hybrid DNA into a host cell, often a bacterium. (actual date not known)
Clone small square First Animal Gene Cloned Stanford and UCSF researchers fused a segment of DNA containing a gene from the African clawed frog (Xenopus) with DNA from the bacterium E. coli and placed the resulting DNA back into an E. coli cell. The frog DNA was copied and the gene it contained directed the production of a specific frog protein. It was the first animal gene to be cloned. (actual date not known)
Capture small square DNA Sequencing Sanger developed a slightly different protocol for sequencing DNA. Sanger's method, where a marker attaches to the growing ends of DNA chains, is used most commonly in labs now. (Sanger is his name) (actual date not known) (actual years were from 1975 -77)
Capture small square First Genetic Engineering Company Herbert Boyer, one of the creators of recombinant DNA technology in the early 70s, founded Genentech with venture capitalist Robert Swanson. (actual date not known)
Capture1 small square Discovery of Introns Richard Roberts' and Phil Sharp's labs showed that eukaryotic genes contain many interruptions, called introns. Human genes are on average interrupted about 10 times, and the introns typically contain about 90 percent of the DNA sequence in the whole gene. (actual date not known)
Capture2 small square First Transgenic Animals Scientists had been able to add new genes to bacterial cells for several years. In the early 80s, they figured out how to add stably-inherited new genes to animals. The first such "transgenic animals" were mice and fruit flies. (actual date not known)
3 small square First Genetic Disease Mapped A genetic marker linked to Huntingtons disease was found on chromosome 4 in 1983, making Huntingtons disease the first genetic disease mapped. (actual date not known)
4 small square Invention of PCR PCR, the polymerase chain reaction, is a technique for amplifying DNA that greatly increased the pace of genetic research. In a few hours, PCR can make billions of copies of a specific segment of DNA. (actual date not known)
Timeline small square First Human Genetic Map The first comprehensive genetic map of human chromosomes was based on 400 restriction fragment length polymorphisms (RFLP). A genetic map contains landmarks, like RFLPs, that occur in various forms. Tracking which variants are inherited in different people can be used to locate genes responsible for diseases. (actual date not known)
5 small square The Human Genome Project Begins The Human Genome Project begins in 1990, the objective was to find and map every gene in the human genome. (the day is not known)
Timeline small square ESTs An expressed-sequence tag (EST) is a stretch of DNA sequence made by copying a portion of an mRNA molecule. They were first proposed as a useful way to find genes in the genome in 1991. (actual date not known)
Timeline small square The Microbial Genome Program Begins The DOE began a Microbial Genome Program in late 1994 to sequence the genomes of some bacteria.
Timeline small square Physical Map of Human Genome Is Completed A physical map uses sequence-tagged sites (STSs) as markers to order large segments of DNA. One of the goals of the HGP was to complete a physical map with a marker every 100,000 base pairs by 1998. The map built by 1995 was a significant milestone toward that goal; it contained 15,086 STSs, spaced an average of 199,000 base pairs apart. (actual date not known)
Timeline small square Human Gene Map Created Scientists created a map showing the locations of ESTs representing fragments of more than 16,000 genes from throughout the genome. (actual date not known)
6 small square First Finished Sequence of a Human Chromosome In 1999, the HGP completed the first finished, full-length sequence of a human chromosome, chromosome 22. This accomplishment demonstrated the power of the HGP method of clone-by-clone sequencing to obtain large amounts of highly accurate sequence. (actual date not known)
5 small square First Draft of the Human Genome Sequence The Human Genome Project international consortium published a first draft of the human genome sequence. The draft sequence covered more than 90 percent of the human genome. (actual date not known)
5 small square The Completion of the Human Genome Project The International Human Genome Sequencing Consortium announced the successful completion of the Human Genome Project more than two years ahead of schedule and under budget. (actual date not known)
Timespan Dates: Timespan Title: Timespan Description:

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1953 - 2004