timeline in genetics
TRANSCRIPT
-
7/28/2019 Timeline in Genetics
1/19
7/4/2011
1
Timeline in Genetics
MBB 1June 30, 2011
-
7/28/2019 Timeline in Genetics
2/19
7/4/2011
2
Early Application & Speculation
Anton van Leeuwenhoek (1632 1723)
-
7/28/2019 Timeline in Genetics
3/19
7/4/2011
3
Early Application & Speculation
1676
Anton van Leeuwenhoek (1632 1723)
The first to describe protozoa and bacteria and torecognize that such microorganisms might play arole in fermentation
His treatise on the flea is a classic, proclaiming thatfleas - like fish, dogs, and humans - are sexual beings
Confirmed (1677) the discovery by Louis DominicusHamm of the existence of sperm cells
The Voyager and The Monk
1859 Charles Darwin (1809 - 1882) hypothesized
the "natural selection." He also inferred theprocess of adaptive radiation, wherein
populations spread out into the environment toexploit specialized resources.
Charles Darwin's landmark book, "On the Originof Species," was published in London. Iteffectively drowned out all other scientific voices,including Mendel's, for decades.
-
7/28/2019 Timeline in Genetics
4/19
7/4/2011
4
The Voyager and The Monk
Darwin's theory makes 2 important points relevantto biotechnology:
Every species is ultimately related to every otherthrough common ancestors
The theory implies that a record of theevolutionary past is present inside every living
thing e.g., anatomical remnants
The Voyager and The Monk
1865
Gregor Mendel (1822 - 1884), an Augustinianmonk, proposed that invisible internal units of
information account for observable traits, andthat these "factors" - which later became knownas genes - are passed from one generation to thenext.
-
7/28/2019 Timeline in Genetics
5/19
7/4/2011
5
More Focused Overview
Mendelian genetics
Frederick Griffith's experiment
Avery, MacLeod, and McCarty experiment
Blender experiment
Events leading to discovery of DNA structure
1866: Mendelian Genetics
Gregor Mendel
Austrian monk
Published laws of
inheritance Experiments with pea
plants
Father of Genetics
Timeline of Genetics: GlaxoSmithKline
Website
-
7/28/2019 Timeline in Genetics
6/19
7/4/2011
6
Mendel's chosenpea traits:
Terms:Phenotype / genotype
alleles
homozygous
heterozygouspure lines / true-breeding
dominant / recessive
F1, F
2
Genetic Terms Introduced
Chromosome - an organized structure of theDNA which contains the genes (packagedDNA)
Gene(from Greek word "genos" "birth") - refers
to a Mendelian hereditary factor- sequence of nucleotides at a specific place
Allelle an alternative form of a gene (onemember of a pair) that is located at a specificposition on a specific chromosome
Genotype - one's genetic make-upPhenotype- one's outward appearance.
-
7/28/2019 Timeline in Genetics
7/19
7/4/2011
7
-
7/28/2019 Timeline in Genetics
8/19
7/4/2011
8
Artificial
cross-pollination
Mendels Results
-
7/28/2019 Timeline in Genetics
9/19
7/4/2011
9
Mendels Results
Mendels Model
Mendel heritable factor
1. Alternative versions of genes account forvariations in inherited characters
Allele (purple vs white color)2. For each character, an organism inherits twoalleles, one from each parent
-
7/28/2019 Timeline in Genetics
10/19
7/4/2011
10
Mendels Model
3. If the two alleles at a locus differ, then one, thedominant allele, determines the organismsappearance (dominant trait); the other, therecessive allele, has no noticeable effect on theorganisms appearance (recessive trait).
4. Law of segregation: Two alleles for aheritable character segregate (separate) during
gamete formation and end up in different gametes
Law of Segregation
-
7/28/2019 Timeline in Genetics
11/19
7/4/2011
11
Mendel's Principles of Genetics
Law of Segregation
Law of Independent Assortment
states that when any individual produces gametes, the copies
of a gene separate so that each gamete receives only one copy
states that alleles of different genes assort independently of
one another during gamete formation
Law of Independent Assortment
-
7/28/2019 Timeline in Genetics
12/19
7/4/2011
12
Fred Griffith's Experiment
1928- Frederick Griffith and his transforming principle
Fred Griffith's Experiment
1928- Frederick Griffith and his transforming principle
-
7/28/2019 Timeline in Genetics
13/19
7/4/2011
13
1944: DNA Genetic Material
Oswald Avery, Colin MacLeod,and Maclyn McCartyreportevidence that, at least in bacteria, the molecule that carriesgenetic information is deoxyribonucleic acid, DNA
1944: DNA Genetic Material
-
7/28/2019 Timeline in Genetics
14/19
7/4/2011
14
1952: Chase and Hershey It is DNA!
Martha Chase andAlfred Hershey: finalproof:
DNA is the substance that transmitsinherited traits.
Hershey receives a Nobel Prize in 1969 for this
work.
Hershey, Chase Blender Experiment
-
7/28/2019 Timeline in Genetics
15/19
7/4/2011
15
-
7/28/2019 Timeline in Genetics
16/19
7/4/2011
16
Erwin Chargaff
Base pairing inDNA
Purine topyrimidineratio = 1:1
Chargaff's Rules, 1949
-
7/28/2019 Timeline in Genetics
17/19
7/4/2011
17
Fig 1: Francis Crick &
James Watson at theCavendish Laboratory.
Fig 2: X-raydiffraction image of 'B-
type DNA taken byRosalind Franklin
-
7/28/2019 Timeline in Genetics
18/19
7/4/2011
18
James Watson and Francis CrickShared Nobel Prize 1962
Structure of the DNA molecule:
Double helix
4 bases: A, G, C, T
Base pairing: Chargaff's rule
50th Anniversary of Discovery of DNA
Rosalind Franklin in mosaic
Maurice Wilkins SharedNobel prize with Watson & Crick
-
7/28/2019 Timeline in Genetics
19/19
7/4/2011
References
Barnum SR. (2005). Biotechnology AnIntroduction.
Campbell NA, Reece JB. (2002). Biology.Benjamin-Cummings, CA, USA.
Grace ES. (2006). Biotechnology Unzipped:Promises and Realities, Revised Second Edition.
Monje VD. (2005). MBB 1 Lecture.