Definition of Genetics, History, Scope, and Application.

1. BIO 106
LECTURE 1

2. CONTENTS
A. Definition of Genetics
B. History of Genetics
C. Scope of Genetics
D. Application of Genetics

3. the study of
HEREDITY and VARIATION

5. 1858: Theory of Natural Selection
Charles Darwin
Alfred Russell Wallace

6. 1859
Charles Darwin

7. 1866
Publication of results on
inheritance of factors
in garden peas
Gregor Mendel

8. 1900: independent discovery
and verification of
Mendel’s principles
Carl Correns
Hugo de Vries
Erich von Tschermak

9. 1902: noticed relationships of
Mendel’s factors with
chromosome behavior
Walter S. Sutton
WS Sutton and Theodor Boveri (studying sea
urchins) independently propose the
chromosome theory of heredity
1901 Hugo de Vries adopts the term mutation

10. coined the terms genetics, allele,
homozygous, heterozygous
1905:
explained how
gender is
determined by
special
chromosomes;
William Bateson

11. : Proposed that some human diseases are
due to "inborn errors of metabolism"
that result from the lack of a
specific enzyme.
Archibald Garrod
independently formulated the
Hardy-Weinberg principle
of population genetics
Godfrey Hardy & Wilhelm Weinberg
1908

12. discovery of how genes are
transmitted by chromosomes;
sex linkage in Drosophila
1910

13. 1927:
X-rays caused
artificial gene
mutations in
Drosophila
Herman J. Muller

14. 1928: Proposed
that some unknown
"principle" had
transformed the
harmless R strain of
Diplococcus to the
virulent S strain.
Frederick Griffith

15. 1931: cytological proof for
crossing-over in maize
with Harriet B. Creighton

16. 1941: Irradiated the red bread mold, Neurospora,
and proved that the gene produces its effect by
regulating particular enzymes;
- proposed 1 gene-1 enzyme concept

17. Reported that they
had purified the
transforming
principle in
Griffith's
experiment and
that it was DNA.
Carl Correns
1944
Oswald Avery
Colin MacLeod
Maclyn McCarty

18. Developed the hypothesis of transposable elements to
explain color variations in corn.
Late 1940s - 1950

19. 1950: Discovered a one-to-one
ratio of A to T and G to C in
DNA samples from a variety
of organisms.
Erwin Chargaff

20. 1951: show by X-ray crystallography that DNA exists as
two strands wound together in a spiral or helical shape
Rosalind Franklin Maurice H.F. Wilkins

21. 1952: Used phages
in which the
protein was
labeled with 35S
and the DNA
with 32P for the
final proof that
DNA is the
molecule of
heredity.
Martha Chase Alfred Hershey

22. 1953: Solved the three-dimensional structure
of the DNA molecule.
Francis Crick James Watson

23. 1956: showed that the diploid chromosome
number for humans is 46
Joe Hin Tijo Albert Levan

24. 1958: Used isotopes of nitrogen
to prove the semiconservative
replication of DNA.
Matthew Meselson &
Frank Stahl

25. 1958: Purified DNA polymerase I
from E. coli, the first
enzyme that made DNA in a
test tube.
Arthur Kornberg
his work in DNA synthesis
led to creating recombinant
DNA and genetic engineering.

26. 1966: Led teams that cracked the genetic code-
that triplet mRNA codons specify each of the
twenty amino acids.
H. Gobind Khorana Marshall Nirenberg

27. 1972
Stanley Cohen
Herb Boyer
Paul Berg

28. 1973: Led the team at Cold
Spring Harbor Laboratory that
refined DNA electrophoresis by
using agarose gel and staining
with ethidium bromide.
Joseph
Sambrook

29. 1973: Showed that a
recombinant DNA molecule
can be maintained and
replicated in E. coli.
Stanley Cohen
(with Annie Chang)

30. Developed the chain
termination
(dideoxy) method
for sequencing DNA.
Fred Sanger
1977
The first genetic engineering
company (Genentech) is
founded, using recombinant
DNA methods to make
medically important drugs.

31. 1978: Somatostatin became the first human
hormone produced using recombinant DNA
technology;
Walter Gilbert coins the terms INTRON
and EXON
1981: Three independent research teams
announced the discovery of human oncogenes
(cancer genes).

32. 1983: Used blood samples
collected by Nancy Wexler
and her co-workers to
demonstrate that the
Huntington's disease gene
is on chromosome 4.James Gusella

33. 1985: Published a paper
describing the
polymerase chain
reaction (PCR), the
most sensitive assay
for DNA yet
devised.
Kary B. Mullis

34. 1988: the Human Genome
Project began with the goal of
determining the entire
sequence of DNA composing
human chromosomes.
Alec Jeffreys
1989: Coined the term DNA fingerprinting
and was the first to use DNA
polymorphisms in paternity, immigration,
and murder cases;
-birth of 1st American test tube baby

35. Identified the gene coding for the cystic fibrosis
transmembrane conductance regulator protein
(CFTR) on chromosome 7 that, when mutant,
causes cystic fibrosis.
Francis Collins Lap-Chee Tsui
1989

36. 1990: First gene replacement therapy-T cells of a
four-year old girl were exposed outside of her
body to retroviruses containing an RNA copy of a
normal ADA gene. This allowed her immune
system to begin functioning.
1993: FlavrSavr tomatoes, genetically
engineered for longer shelf life, were
marketed.
1997 : Complete Saccharomyces cerevisiae
genome is sequenced; complete E. coli genome
is sequenced

37. 1998 Caenorhabditis elegans becomes the first
animal whose genome is totally sequenced
1999 A human MHC (HLA-DR52) haplotype is
totally sequenced (October).
Human chromosome 22 becomes the first one
to be sequenced completely (November)
2003 Complete sequence of human Y-chromosome
was published

39. 3 major fields of Genetics:
1. Transmission genetics
2. Molecular and biochemical
genetics
3. Population and biometrical
genetics

40. TRANSMISSION GENETICS/CLASSICAL GENETICS
Studies:
- Basic principles of genetics
- transmission of genetic material from one generation
to the other
- Focus: individual organism
- emphasis:
Relationship between chromosomes and heredity
 Arrangement of genes on the chromosomes
 Gene mapping

41. MOLECULAR AND BIOCHEMICAL GENETICS
- study of the chemical nature (structure and function)
of genes
- Emphasis:
 How genetic information is encoded, replicated and
processed.
 The cellular processes of
replication, transcription and translation
 Gene regulation, the process that controls the
expression of genetic information.

42. POPULATION AND BIOMETRICAL GENETICS
- study of the behavior and effects of genes in population, often
using mathematical models
- Focus: the group of genes found in a population.
- emphasis: How the genetic composition of a group changes over
time.
- Can include quantitative genetics (predict the response to
selection given data on the phenotype and relationships of
individuals) and ecological genetics (wild populations of
organisms, and attempts to collect data on the ecological
aspects of individuals as well as molecular markers from those
individuals)

43. Other Fields:
1. Behavioral genetics
- studies the influence of varying genetics on animal
behavior, the effects of human disorders as well as
its causes; has yielded some very interesting
questions about the evolution of various behaviors,
and even some fundamental principles of evolution in
general.
2. Clinical genetics
- diagnosis, treatment, and counseling of patients with
genetic disorders or syndromes

45. AGRICULTURE
Selective breeding:
cross-breeding of two
parents, each with some
good traits, to produce
offspring with the good
traits of both parents

48. BENEFITS OF Selective Breeding
better resistance to pests and diseases
improved nutritional value (superior quality)
fruits with longer shelf life
bigger animal, more meat, more milk production
Increase food production
Disadvantage:
removal of some genes from the gene pool

49. TRANSGENIC ORGANISMS:
Transgenic plants: resistant to pests, diseases
Transgenic animals: chickens with
HGH to make them grow large and
very fast
Transgenic bacteria: for mass production of
insulin, HGH, blood clotting factor

50. MEDICINE
Accurate diagnosis of diseases
Preventing use of medicine or disease prevention
Inherited drug sensitivities
Chromosomal abnormalities
Production of vaccines, antibodies, vitamins, insulin
Gene therapy
Future: personalized medicine

51. LEGAL (genetic fingerprinting)
Crimes (forensic science)
Parentage

52. INDUSTRIES
- Provide some synthetically produced raw materials
for industries
Brewing industry

53. INDUSTRIES
The pharmaceutical industry has developed strains of
molds, bacteria, and other microorganisms high in
antibiotic yield. (examples: Penicillin and cyclosporin
from fungi, streptomycin and ampicillin from
bacteria)

54. HUMANS:
possibility of making children with only the desirable
traits
Babies who have deficiency could be treated with
additions being done to their genetic structure.
Those who cannot reproduce due to medical
complications have also seen positive results with
surrogate parent's concept becoming available.
Increasing life span (vaccination, medications,
vitamins)

55. ENVIRONMENT
Oil spills
Polluted waterways
BIOREMEDIATION

56. ENVIRONMENT
- Protection of
valuable wild
populations
(genetic monitoring
using genetic
markers) thus
probably solving
problems causing
reduction of
population
Distribution of elephant in Tanzania