INTRODUCTION TO INTRODUCTION TO PLANT MOLECULAR GENETICSPLANT MOLECULAR GENETICS
Why young breeders Why young breeders must study genetics?must study genetics?
GeneticsGenetics Branch of biology dealing with heredity Branch of biology dealing with heredity
and variationand variation Branch of biology dealing with the study Branch of biology dealing with the study
of the geneof the geneCenter of Genetics: Unit of heredity Nucleic acid Protein synthesis Characteristics
of organisms Relationship
between genes and traits
Genetics is a broad disciplineIt encompasses
molecular, cellular, organism, and population
Three Major Areas of GeneticsThree Major Areas of Genetics
Classical Genetics(Transmission)
Molecular Genetics
Evolutionary Genetics
Mendel’s Principles
Genom Quantitative Genetics
Meiosis + mitosis
DNA structure Population Genetics
Sex determination
Chemistry of DNA
Evolution
Sex linkage Gene expression Speciation
Chromosomal mapping
Control of gene expression
Cytogenetics DNA cloning & Marker
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 ?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 expressedStudy of molecular basis of inheritanceMolecular genetics
Basis of Modern Breeding
Modern BreedingModern Breeding
Systematic procedures used to Systematic procedures used to improve trait phenotypes by improve trait phenotypes by
crossing and selection, directed crossing and selection, directed manipulation of the genotype at manipulation of the genotype at
the DNA sequence level, and the DNA sequence level, and introduction of new genes.introduction of new genes.
Developing suitable cultivarsDeveloping suitable cultivars Each cultivar is developed with special purposeEach cultivar is developed with special purpose
Each cultivar responses differently to environmental changeEach cultivar responses differently to environmental change Climate Change needs special cultivarsClimate Change needs special cultivars
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).
Breeding needs advance technology
Molecular Genetics:A Short History
18691869 Miescher isolated DNA for the first timeMiescher isolated DNA for the first time
19441944 Avery provided evidence that DNA is the Avery provided evidence that DNA is the genetic materialgenetic material
19531953 Watson and Crick proposed the double helix as Watson and Crick proposed the double helix as the structure of DNAthe structure of DNA
19571957 Kornberg discovered DNA polymeraseKornberg discovered DNA polymerase
19611961 Marmer and Doty discovered DNA renaturationMarmer and Doty discovered DNA renaturation
19621962 Arber, Nathans and Smith discovered Arber, Nathans and Smith discovered restriction endonucleasesrestriction endonucleases
19661966 Nirenberg, Ochoa, and Khorana figured out the Nirenberg, Ochoa, and Khorana figured out the genetic code.genetic code.
Molecular Genetics:A Short History
19671967 Geller discovered DNA ligaseGeller discovered DNA ligase
1972-1972-7373
Boyer, Cohen and Berg develop DNA cloning Boyer, Cohen and Berg develop DNA cloning techniquestechniques
19751975 Southern developed gel-transfer hybridizationSouthern developed gel-transfer hybridization
1975-1975-77 77
Sanger and Barrel and Maxam and Gilbert Sanger and Barrel and Maxam and Gilbert developed rapid DNA sequencing methodsdeveloped rapid DNA sequencing methods
1981-1981-82 82
Palmiter and Brinster produced transgenic Palmiter and Brinster produced transgenic mice mice
Spradling and Rubin produced transgenic fruit Spradling and Rubin produced transgenic fruit fliesflies
19851985 Mullis and colleagues invented the Polymerase Mullis and colleagues invented the Polymerase Chain Reaction (PCR)Chain Reaction (PCR)
Molecular Genetics:A Short History
19901990 Human Genome ProjectHuman Genome Project
19951995 Microarray technique by Brown and DavisMicroarray technique by Brown and Davis
20002000 Arabidopsis and Drosophila genome project Arabidopsis and Drosophila genome project
2000 2000 The first gene controlling a quantitative trait is The first gene controlling a quantitative trait is cloned by Tanksleycloned by Tanksley
20022002 The draft of rice genome sequence is publishedThe draft of rice genome sequence is published
2004-2004-20052005
The development of sequencing by synthesis The development of sequencing by synthesis technologytechnology
The The Molecular Molecular Basis of Basis of Inheritance?Inheritance?
The The Molecular Molecular Basis of Basis of Inheritance ?Inheritance ?
Genome Genes, regulatory sequences Others?
The The Molecular Molecular Basis of Basis of Inheritance ?Inheritance ?
RNA
Polypeptides
1.Genome2.Chromosome
3.Gene4.DNA/RNA
5.Nucleic Acid6.Protein
7.Amino Acid
The Molecular Basis of Inheritance?
GenomeTotal genetic information carried by a single set of chromosome in a haploid nucleus
ChromosomeA DNA – histone protein thread, usually associated with RNA, occurring in the nucleus of a cellChromosomes contain hundreds of genes encoded within their DNA.
Genesegment of a chromosome that contains the heredity traits of an organism
DNADouble stranded form of genetic material of organisms
The The Molecular Molecular Basis of Basis of Inheritance ?Inheritance ?
RNA Single stranded form of genetic material of
organisms result of the DNA transcriptionNucleotide
Unit structure of nucleic acidProtein
a polymer that has a high relative molecular mass of amino acids
Polypeptidea linear polymer that consists of ten or more amino acids linked by peptide bonds
Amino AcidAn organic compound containing an acidic carboxyl group and a basic amino group
The The Molecular Molecular Basis of Basis of Inheritance ?Inheritance ?
INTRODUCTION TO MOLECULAR INTRODUCTION TO MOLECULAR GENETICSGENETICS
GenomeGenome Genetic Material (DNA & RNA)Genetic Material (DNA & RNA)
DNA structureDNA structure Chemistry of DNA Chemistry of DNA
Gene expression (transcription and translation)Gene expression (transcription and translation) Control of gene expressionControl of gene expression
Molecular toolMolecular tool DNA cloningDNA cloning DNA markerDNA marker
Grading system
Grade : 0 – 100
A > 80 B – D → 45 – 80 (Normal distribution)
E < 45
Grade composition
Home work : 30
Mid-term : 30
Final Exam : 40