Chapter 1: Introduction to genetics
A brief introduction about myself
1987.9-1991.7
Southwest Teachers’ University, Bachelor 1991.9-1997.7
Sichuan University, Master, Ph D 1997.7-now: Hubei University 2003.4-2004.3
Swedish University of Agricultural Sciences
Why do I want to teach in English? China is becoming more and more
international All the best scientific journals are in
English We have to be able to communicate in
English What is the problem with our learning
English
What should we achieve?
Communicate in English Read English literatures Know the basics of genetics Know how to work with science
Science and Civilisation in China
The question of Joseph Needham
Why did modern science originate in western countries instead of China?
Why can’t we native Chinese scientists get Nobel prize?
Why could Mendel discover the two basic genetic laws?
What should we learn from Mendel, Morgan, Watson, Crick, Etc.?
How will we go ahead?
I: teach a few chapters You: teach the other chapters We: discuss
1.1 What is genetics?
genetics :The branch of biology that deals with heredity variation.
heredity : the similarity between progenitors and progeny
Variation: difference between generations and individuals of the same species
1.2 History of genetics
Prehistoric times: domesticated animals and cultivated plants
Our ancient ancestors learned that desirable and undesirable traits are passed to successive generations and that by influencing their breeding, many desirable varieties of animals and plants could be obtained.
The Greek influence: Hipocrates
Hipocrates argued that male semen is formed in numerous parts of the body and is transported through blood vessels to the testicles.
Pangenesis: Particles or fluids from various parts of the body accumulate in germ cells, and are transmitted to the offspring.
This theory believed in the passing on of characters acquired during lifetime of the individual.
Hipocrates
The Greek influence: Aristotle
Aristotle proposed that male semen was formed from blood rather than from each organ, and that its generative power reside in a vital heat that it contained.
Aristotle
Before Mendel: Preformation
Leeuwenhoek and his students believed they saw through their microscope small encapsulated creatures within the sperms.
Bonnet (1720-1793): An embryo contained a smaller embryo, which contain another smaller embryo, so on.
Before Mendel: epigenesis
Wolff suggested that organisms develop by epigenesis, i.e., development starts from undifferentiated fertilized egg and proceeds through successive formation and addition of new parts which did not exist there before.
Doctrine of use and disuse
Lamark (1744-1829) proposed that organisms acquire or lose characteristics that then became inheritable.
Lamark
Pangenesis and the inheritance of acquired characteristics
Charles Darwin described the physical units representing each body part that were gathered by the blood into the semen. He felt these units determined the nature or form of each body part and they could respond in an adaptive way to the external environment. Once altered, such changes would be passed onto offspring, allowing for the inheritance of acquired characteristics.
Charles Darwin
August Weismann and Francis Galton Weismann cut off the the tails of mice for 2
2 generations, yet the newborn displayed tails just as long as those of their ancestors.
Galton performed blood transfusions among different breeds of rabbits, without any hereditary consequences.
August Weismann
Francis Galton
Gregor Mendel
Gregor Mendel
Mendel published his classic paper in 1866. In this paper Mendel demonstrated a number of statistical patterns underlying inheritance and developed a theory involving hereditary factors in the germ cells to explain these patterns.
After Mendel
1900, De Vries, Correns and Tschermak rediscovered Mendel’s paper
1903, Sutton and Boveri, Chromosomal theory of inheritance
1909, Johansen coined gene for genetic factor
Around 1910, Morgan and his students Sturtevant, Bridges and Muller: gene theory
Morgan TH
After Mendel
1927, Muller and Stadler: irradiation genetics
1940, McClintock: transposon 1941, Beadle and Tatum: one gene for on
e enzyme Avery (1944), Hershey (1952): genetic mat
erial is DNA instead of protein 1953, Waston and Crick: double helix mo
del
Barbara McClintock
Discovered transposon
in 1940 and was
awarded Nobel Prize
in 1983.
Watson and Crick
After Mendel
1973, genetic engineering. 1990, Human Genome Project→genomics. 1997, Clone of Dolly. Functional genomics; Protemics
Genetics and Agriculture
Hybrid vigor Disease resistance Pest resistance Herbicide resistance Select for various mutants Utilization of bacteria to produce useful
industrial materials
Yuan Longping
The father of hybrid rice
Fu Tingdong
Found the first useful
male sterile line--
CMS Polima in
Rapeseed.
Genetics and Medicine
Understanding the genetic basis of many disease including cancer.
Development of new medicines through genetic engineering.
Genetics and environment protection Utilization of genetically modified plants to
clean heavy metals. Utilization of genetically modified bacteria
to clean the water. etc.