Download Molecular Genetics

INTRODUCTION TO
PLANT MOLECULAR GENETICS
Why young breeders must
study genetics?
Genetics
Branch of biology dealing with heredity and variation
 Branch of biology dealing with the study of the gene
Center of Genetics:
 Unit of heredity
 Nucleic acid
 Protein synthesis
 Characteristics of
organisms
 Relationship between
genes and traits
Genetics is a broad discipline
 It encompasses molecular,
cellular, organism, and
population
Three Major Areas of Genetics
Classical Genetics
(Transmission)
Molecular Genetics Evolutionary
Genetics
Mendel’s Principles
Meiosis + mitosis
Sex determination
Sex linkage
Chromosomal
mapping
Cytogenetics
Genom
DNA structure
Chemistry of DNA
Gene expression
Control of gene
expression
DNA cloning &
Marker
Quantitative Genetics
Population Genetics
Evolution
Speciation
Major Subdisciplines of Genetics
Transmission Genetics: focuses on the transmission
of genes and chromosomes in individuals from
generation to generation.
Molecular Genetics: focuses on the structure and
function of genes at the molecular level.
Evolutionary genetics: focus on the study of genetic
basis of changes in organism over time
 Population Genetics: focuses on heredity in groups of
individuals for traits determined by one or only a few genes.
 Quantitative Genetics: focuses on heredity in groups of
individuals for traits determined by many genes simultaneously.
Molecular Genetics ?
 The field of biology that studies the structure and
function of genes at a molecular level.
Study of the expression, regulation and inheritance of
genes at the level of DNA and its transcription products
Study of gene structure, function and regulation – below
the organism level
Study of genes and how they are expressed
Study of molecular basis of inheritance
Molecular genetics
Basis of Modern Breeding
Modern Breeding
Systematic procedures used to improve
trait phenotypes by crossing and selection,
directed manipulation of the genotype at
the DNA sequence level, and introduction
of new genes.

Developing suitable cultivars
Each cultivar is developed with special purpose
Each cultivar responses differently to environmental change
 Climate Change needs special cultivars


Breeding needs advance technology
If breeding work fails to help improving resource utilization
efficiency and tackling the effect of global warming, then
agriculture will probably not be sustainable and as a result the size
of global community will decline as resources are exhausted and
environment is not friendly anymore to human being
(Beversdorf, 1994).
Molecular Genetics:
A Short History
1869
Miescher isolated DNA for the first time
1944
Avery provided evidence that DNA is the genetic material
1953
1957
Watson and Crick proposed the double helix as the structure
of DNA
Kornberg discovered DNA polymerase
1961
Marmer and Doty discovered DNA renaturation
1962
Arber, Nathans and Smith discovered restriction
endonucleases
Nirenberg, Ochoa, and Khorana figured out the genetic code.
1966
Molecular Genetics:
A Short History
1967
Geller discovered DNA ligase
1972-73 Boyer, Cohen and Berg develop DNA cloning techniques
1975
Southern developed gel-transfer hybridization
1975-77 Sanger and Barrel and Maxam and Gilbert developed rapid
DNA sequencing methods
1981-82 Palmiter and Brinster produced transgenic mice
Spradling and Rubin produced transgenic fruit flies
1985
Mullis and colleagues invented the Polymerase Chain Reaction
(PCR)
Molecular Genetics:
A Short History
1990
Human Genome Project
1995
Microarray technique by Brown and Davis
2000
Arabidopsis and Drosophila genome project
2000
The first gene controlling a quantitative trait is cloned by
Tanksley
The draft of rice genome sequence is published
2002
20042005
The development of sequencing by synthesis technology
The Molecular Basis of Inheritance?
The Molecular Basis of Inheritance ?
The Molecular Basis of Inheritance ?
Genome
Genes, regulatory sequences
Others?
RNA
Polypeptides
The Molecular Basis of Inheritance?
1. Genome
2. Chromosome
3. Gene
4. DNA/RNA
5. Nucleic Acid
6. Protein
7. Amino Acid
The Molecular Basis of Inheritance ?
 Genome
Total genetic information carried by a single set of chromosome in a haploid
nucleus
 Chromosome
A DNA – histone protein thread, usually associated with RNA, occurring in the
nucleus of a cell
Chromosomes contain hundreds of genes encoded within their DNA.
 Gene
segment of a chromosome that contains the heredity traits of an organism
 DNA
Double stranded form of genetic material of organisms
The Molecular Basis of Inheritance ?
RNA
Single stranded form of genetic material of organisms result of the DNA
transcription
Nucleotide
Unit structure of nucleic acid
Protein
a polymer that has a high relative molecular mass of amino acids
Polypeptide
a linear polymer that consists of ten or more amino acids linked by peptide
bonds
Amino Acid
An organic compound containing an acidic carboxyl group and a basic amino
group
INTRODUCTION TO MOLECULAR
GENETICS
 Genome
 Genetic Material (DNA & RNA)
 DNA structure
 Chemistry of DNA
 Gene expression (transcription and translation)
 Control of gene expression
 Molecular tool
 DNA cloning
 DNA marker
Grading system
Grade : 0 – 100
 B–D
 A > 80
→ 45 – 80 (Normal distribution)
 E < 45
Grade composition
Home work
Mid-term
Final Exam
:
:
:
30
30
40