History of Genetics

Mendel- worked with pea plants and discovered the laws of heredity (work was ignored until 1900 when rediscovered)

Meischer- discovered DNA, called nuclein, extracted from pus filled bandages

Morgan- discovered that chromosomes control traits when he studied white eyed male mutant drosophila

Pre 1920’s

Muller- discovered that x-rays mutate DNA (warnings were ignored)

Beadle and Tatum- discovered that enzymes were gene products, one gene one enzyme theory, when working with Neospora (bread mold)

McClintock- discovered that genes were not stagnant and could transpose onto different chromosomes (jumping genes) when studying corn kernel color.

1920-1949

Chargaff- discovered that the four bases ACTG are always present in a certain ratio, 1:1, A:T and G:C, called Chargaff's rule.

Hershey and Chase- showed that DNA was the molecule responsible for passing genes when studying bacteriophage.

Watson, Crick and Franklin- Watson and Crick used stolen X-ray crystallography images from Franklin’s lab to determine the double helix structure of DNA.

Early 1950’s

Crick- developed the central dogma theory that explains how genes encode for proteins.

Meselson and Stahl- discovered that DNA replicates in a semi-conservative manner. One stand is conserved as a template and the other is newly synthesized during replication.

A. Kornberg- isolated the enzyme that replicates DNA, DNA polymerase, and discovered DNA could be replicated in vitro, laid the ground work for Mullis’ PCR.

Late 1950’s

Nirenberg- cracked the universal genetic code, by studying E. coli. He determined that there were 64 codons that coded for the 20 amino acids present in all living organisms.

Jacob and Monod- were the first to understand how a gene was regulated (turned on/off) by studying the lac operon, a gene that codes for an enzyme that breaks down lactose.

1960’s

Cohen and Boyer- used restriction enzymes to make recombinant DNA, DNA that has non native genes inserted into it.

R. Kornberg- discovered chromatin structure. Determined that DNA was wound around histone proteins that accounted for its condensed packaging.

Sanger- discovered the Sanger di-deoxy method of DNA sequencing.

1970’s

Mullis- discovered that DNA could amplified, so that it could be studied better. The technique was called PCR polymerase chain reaction.

Jeffreys- developed DNA fingerprinting technique that is used in many applications. He used restriction enzymes to digest DNA into a banding pattern that is compared to a known sample of DNA.

1980’s

King- discovered that chips and humans share 99% of genes. She also discovered the breast cancer gene BRCA1, was the first to link cancer to an actual gene.

Venter and Collins- Collins discovered programmed call death and they both work on the human genome project. Completely sequenced the genome for several organism including humans.

1990’s-Present

http://www.dnai.org/timeline/https://www.youtube.com/watch?v=GTiOETaZg4whttps://www.youtube.com/watch?v=CeXfh96pe08http://

www.dnalc.org/resources/nobel/beadle_tatum.html

https://www.youtube.com/watch?v=SGViDFQ4Zjkhttps://

www.youtube.com/watch?v=QWwKkGmwhsAhttps://www.youtube.com/watch?v=6ldtdWjDweshttps://www.youtube.com/watch?v=ZZ-XUG46VDIhttps://www.youtube.com/watch?v=mkPawVQfZko

Links