INTRODUCTION TO MOLECULAR INTRODUCTION TO MOLECULAR GENETICSGENETICS

GeneticsGenetics The study of heredityThe study of heredity The study of how differences between The study of how differences between

individuals are transmitted from one individuals are transmitted from one generation to the nextgeneration to the next

The study of how information in the genes The study of how information in the genes is used in the development and is used in the development and functioning of the adult organismfunctioning of the adult 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 process

It doesn’t tell you how direct the role is

Biochemistry tells you what a protein can do in vitro

It doesn’t tell you whether it really does it in vivo

Three Major Areas of GeneticsThree Major Areas of Genetics

Classical Classical GeneticsGenetics

(Transmission)(Transmission)

Molecular Molecular GeneticsGenetics

Evolutionary Evolutionary GeneticsGenetics

Mendel’s PrinciplesMendel’s Principles GenomGenom Quantitative Quantitative GeneticsGenetics

Meiosis + mitosisMeiosis + mitosis DNA structureDNA structure Population GeneticsPopulation Genetics

Sex determinationSex determination Chemistry of DNAChemistry of DNA EvolutionEvolution

Sex linkageSex linkage TranscriptionTranscription SpeciationSpeciation

Chromosomal Chromosomal mappingmapping

TranslationTranslation

Cytogenetics Cytogenetics Control of gene Control of gene expressionexpression

DNA cloningDNA cloning

Major Subdisciplines of GeneticsMajor Subdisciplines of Genetics

Transmission Genetics: Transmission Genetics: focuses on the focuses on the transmission of genes and chromosomes in transmission of genes and chromosomes in individuals from generation to generation.individuals from generation to generation.

Molecular Genetics:Molecular Genetics: focuses on the structure focuses on the structure and function of genes at the molecular level.and function of genes at the molecular level.

Population Genetics:Population Genetics: focuses on heredity in focuses on heredity in groups of individuals for traits determined by groups of individuals for traits determined by one or only a few genes.one or only a few genes.

Quantitative Genetics:Quantitative Genetics: focuses on heredity focuses on heredity in groups of individuals for traits determined in groups of individuals for traits determined by many genes simultaneously.by many genes simultaneously.

Molecular Genetics ?Molecular Genetics ?Understanding the molecular basis of biological

processes through studies on the gene

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

Study of genes and how they are expressed

The Molecular Basis of Genetics

Molecular Biology?

Study of molecules in cells

Chromosomal RegionsChromosomal Regions HeterochromatinHeterochromatin

compact; compact; few genes; few genes; largely structural rolelargely structural role

EuchromatinEuchromatincontains most of the genes.contains most of the genes.

ChromosomeChromosome

Two broad approachesTwo broad approaches

Classical:

Reverse:

biologicalprocess

genein hand

identifymutants

createmutants phenotype? biological

process

findthe gene

biochemicalfunction

Classical Classical Method Method

GenotypeGenotype PhenotypePhenotype• Discover new phenotypeDiscover new phenotype• Prove that it has genetic basis (i.e. that you Prove that it has genetic basis (i.e. that you

discovered a new mutation)discovered a new mutation)• Find the gene that has mutatedFind the gene that has mutated• Understand what and how the wild type gene doesUnderstand what and how the wild type gene does

ClassicalClassical Method Method

Genotype Genotype PhenotypePhenotype• Discover new phenotypeDiscover new phenotype• Prove that it has genetic basis (i.e. that you Prove that it has genetic basis (i.e. that you

discovered a new mutation)discovered a new mutation)• Find the gene that has mutatedFind the gene that has mutated• Understand what and how the wild type gene doesUnderstand what and how the wild type gene does

Reverse geneticsReverse genetics

Genotype Genotype PhenotypePhenotype• Change something in a known geneChange something in a known gene• Observe phenotypic effectObserve phenotypic effect• Find out why you see what you seeFind out why you see what you see• Understand what and how the wild type gene doesUnderstand what and how the wild type gene does

Reverse geneticsReverse genetics

Genotype Genotype PhenotypePhenotype• Change something in a known geneChange something in a known gene• Observe phenotypic effectObserve phenotypic effect• Find out why you see what you seeFind out why you see what you see• Understand what and how the wild type gene Understand what and how the wild type gene

doesdoes

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

Transcription and translationTranscription and translation Control of gene expressionControl of gene expression

Molecular toolMolecular tool DNA cloningDNA cloning

Grading systemGrading system

Grade : 0 – 100Grade : 0 – 100

A > 80A > 80 B – DB – D → 45 – 80 (Normal distribution)→ 45 – 80 (Normal distribution)

E E < 45< 45

Grade composition

Home workHome work :: 3030

Mid-termMid-term :: 3030

Final ExamFinal Exam :: 4040