INTRODUCTION TO INTRODUCTION TO PLANT MOLECULAR GENETICSPLANT MOLECULAR GENETICS

GeneticsGenetics The study of heredity

The study of inherited phenotypes The study of how differences between individuals

are transmitted from one generation to the next The study of how information in the genes is used in

the development and functioning of the organism

Genetics Biochemistry

Gene products are studied in vivo through the genes that encode them

Gene products are purified and studied in vitro

Genetic analysis tells you that the product has a role in the processGenetics is the study of inheritance, it doesn’t tell you how direct the role is

Biochemistry tells you what a protein can do in vitroBiochemistry is the study of the chemistry of living organisms and/or cells, it doesn’t tell you whether it really does it in vivo

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

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 ? Study of the expression, regulation and

inheritance of genes at the level of DNA and its transcription products

Understanding the molecular basis of biological processes through studies on the

geneStudy of gene structure, function and regulation – below the organism level

Study of genes and how they are expressed Molecular Basis of Genetics

Molecular Biology?Study of molecules in cells

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)

The The Molecular Molecular Basis of Basis of Genetics ?Genetics ?

The The Molecular Molecular Basis of Basis of Genetics ?Genetics ?

Genome Genes, regulatory sequences Others?

The The Molecular Molecular Basis of Basis of Genetics ?Genetics ?

RNA

Polypeptides

1.Genome2.Chromosome

3.Gene4.DNA/RNA

5.Nucleic Acid6.Protein

7.Amino Acid

The Molecular Basis of Genetics ?

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 Genetics ?Genetics ?

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 Genetics ?Genetics ?

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

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