biology 2250 principles of genetics
DESCRIPTION
Biology 2250 Principles of Genetics. Instructors: Dr. Steven M. Carr Molecular Genetics Dr. David J. Innes Mendelian Genetics. Course Web Pages. Dr.Innes: www.mun.ca/biology/dinnes/B2250/B2250.html Dr. Carr: www.mun.ca/biology/scarr/Bio2250.html - PowerPoint PPT PresentationTRANSCRIPT
Biology 2250Biology 2250Principles of GeneticsPrinciples of Genetics
Instructors:Instructors:
Dr. Steven M. CarrDr. Steven M. Carr Molecular GeneticsMolecular Genetics
Dr. David J. InnesDr. David J. Innes Mendelian GeneticsMendelian Genetics
Course Web PagesCourse Web Pages
Dr.Innes:Dr.Innes: www.www.munmun.ca/biology/.ca/biology/dinnesdinnes/B2250/B2250.html/B2250/B2250.html
Dr. Carr:Dr. Carr: www.mun.ca/biology/scarr/Bio2250.html www.mun.ca/biology/scarr/Bio2250.html
Text Web Page:Text Web Page: http://www.http://www.whfreemanwhfreeman.com/.com/mgamga//
Virtual Fly:Virtual Fly: http://www.biologylabsonline.com/ http://www.biologylabsonline.com/
Tentative Lecture Dates Tentative Lecture Dates and Topicsand Topics
Carr: Carr: Sept. 8 – Oct. 4Sept. 8 – Oct. 4 Structure and function of DNA and genesStructure and function of DNA and genes
Innes: Innes: Oct. 13 – Nov. 15 Oct. 13 – Nov. 15 Mendelian GeneticsMendelian Genetics
Carr:Carr: Nov. 22 – Dec. 1 Nov. 22 – Dec. 1 Molecular GenomicsMolecular Genomics
Tests: I Oct. 6 (Thurs)Tests: I Oct. 6 (Thurs)
II Nov.17 (Thurs)II Nov.17 (Thurs)
Weekly Online QuizzesWeekly Online Quizzes
MarksMarksOct. 14 Example Quiz 2** Oct. 14 Example Quiz 2** for logging in for logging in
Oct. 21 Quiz 1 2Oct. 21 Quiz 1 2
Oct. 28 Quiz 2 2Oct. 28 Quiz 2 2
Nov. 4 Quiz 3 2Nov. 4 Quiz 3 2
Nov. 10 Quiz 4 2Nov. 10 Quiz 4 2
WebCT QuizzesWebCT Quizzes
Log in: http://webct.mun.ca:8900/Log in: http://webct.mun.ca:8900/
Webct Webct quizzesquizzes
Course GoalsCourse Goals
• Understanding of basic geneticsUnderstanding of basic genetics
• Solve problemsSolve problems
• Think and think criticallyThink and think critically
• Contribute to a discussion on Contribute to a discussion on
current issues in geneticscurrent issues in genetics
(GMO, gene therapy…)(GMO, gene therapy…)
What is Genetics ?What is Genetics ?- Genetics is the study of heredity and variation- Genetics is the study of heredity and variation
- Examples of genetic variation (within species)- Examples of genetic variation (within species)
1. Domesticated species1. Domesticated species
2. Human genetics2. Human genetics
3. Natural Populations3. Natural Populations
Genetic variation Genetic variation Phenotypic variation Phenotypic variation
Molecular genetic variationMolecular genetic variation
Cultivated varietiesCultivated varieties
Animal BreedsAnimal Breeds
Human GeneticHuman Genetic
VariationVariation
Natural Natural PopulationsPopulations
Which Which suspect suspect matches matches blood stain ?blood stain ?
Molecular Genetic VariationMolecular Genetic Variation
DNA FingerprintDNA Fingerprint
DNA SequenceDNA Sequence
Protein variationProtein variation
Subareas of GeneticsSubareas of Genetics
cytogeneticscytogenetics
molecular geneticsmolecular genetics
human geneticshuman genetics
population geneticspopulation genetics
quantitative geneticsquantitative genetics
developmental geneticsdevelopmental genetics
immunogeneticsimmunogenetics
etc. etc.etc. etc.
Genetic JournalsGenetic JournalsAmerican Journal of Medical Genetics Clinical GeneticsAmerican Journal of Medical Genetics Clinical Genetics
Developmental Genetics Human Molecular GeneticsDevelopmental Genetics Human Molecular Genetics
Genetics European J. of Human GeneticsGenetics European J. of Human Genetics
Genetics Selection Evolution Nature GeneticsGenetics Selection Evolution Nature Genetics
Genetika Fungal Genetics and BiologyGenetika Fungal Genetics and Biology
Genome Cancer Genetics and CytogeneticsGenome Cancer Genetics and Cytogenetics
Genomics American J. Human Genetics Genomics American J. Human Genetics
Heredity Annals of Human GeneticsHeredity Annals of Human Genetics
Hereditas Opthalmic GeneticsHereditas Opthalmic Genetics
Japanese Journal of Human Genetics Human GeneticsJapanese Journal of Human Genetics Human Genetics
Journal of Heredity Current GeneticsJournal of Heredity Current Genetics
Molecular Biology and Evolution Animal GeneticsMolecular Biology and Evolution Animal Genetics
Molecular Ecology Brazilian J. GeneticsMolecular Ecology Brazilian J. Genetics
Molecular and General Genetics Biochemical GeneticsMolecular and General Genetics Biochemical Genetics
Theoretical and Applied Genetics J. of Medical GeneticsTheoretical and Applied Genetics J. of Medical Genetics
Trends in Genetics (http://www.trends.com/tig/default.htm)Trends in Genetics (http://www.trends.com/tig/default.htm)
History of GeneticsHistory of Genetics
• Domestication of animalsDomestication of animals
• Cultivation of plantsCultivation of plants
Historical NotesHistorical Notes
1953 1953 J. D.J. D. Watson and F. Crick(*)Watson and F. Crick(*)
DNA StructureDNA Structure
http://www.sil.si.edu/Exhibitions/Science-and-the-http://www.sil.si.edu/Exhibitions/Science-and-the-Artists-Book/bioc.htmArtists-Book/bioc.htm
Advances in GeneticsAdvances in Genetics
• Human Genome Sequence Human Genome Sequence
http://www.hgsc.bcm.tmc.edu/http://www.hgsc.bcm.tmc.edu/
• Drosophila Drosophila Genome sequenceGenome sequence
http://flybase.bio.indiana.edu/http://flybase.bio.indiana.edu/
• Other organsims:Other organsims:
http://daphnia.cgb.indiana.edu/http://daphnia.cgb.indiana.edu/
http://www.jgi.doe.gov/ http://www.jgi.doe.gov/
Genetic InformationGenetic Information
Online Mendelian Inhertitance in Man (OMIM)Online Mendelian Inhertitance in Man (OMIM)
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=OMIMdb=OMIM
Online Mendelian Inhertiance in Animals (OMIA)Online Mendelian Inhertiance in Animals (OMIA)
http://omia.angis.org.au/http://omia.angis.org.au/
Ethical Issues in GeneticsEthical Issues in Genetics
Ethical Issues in GeneticsEthical Issues in Genetics
• Genetically modified organisms (GMO)Genetically modified organisms (GMO)
• Gene therapy (Parkinson’s) Gene therapy (Parkinson’s) http://hdlighthouse.org/research/genetherapy/updhttp://hdlighthouse.org/research/genetherapy/updates/0053parkinson.phtmlates/0053parkinson.phtml
• Designer genesDesigner genes
• Data banks of DNA finger prints (criminals?)Data banks of DNA finger prints (criminals?)
• Cloning (Stem cell research)Cloning (Stem cell research)
CloningCloning19971997
19981998
1999 - 20021999 - 2002
DollyDolly““An udder way of An udder way of making lambs”making lambs”
nucleusnucleus fosterfoster eggegg
SheepSheep
MiceMice
PigPig
GoatGoat
CowCow
“Cc” copy cat
Genetics in the NewsGenetics in the News
Basic Concepts of GeneticsBasic Concepts of Genetics(Chapter 1)(Chapter 1)
NucleusNucleus contains genetic material contains genetic material
DNADNA genetic material genetic material
4 bases (nucleotides G, C, A, T) 4 bases (nucleotides G, C, A, T)
GeneGene functional unit of heredity functional unit of heredity
sequence of 4 nucleotidessequence of 4 nucleotides
ChromosomeChromosome linear DNA molecule linear DNA molecule
Pairs of Chromosomes Pairs of Chromosomes (maternal, paternal)(maternal, paternal)
Two sets of chromosomes: diploidTwo sets of chromosomes: diploid
One set of chromosomes: haploidOne set of chromosomes: haploid
DNA ReplicationDNA Replication
1. Transcription of mRNA from DNA1. Transcription of mRNA from DNA
2. Translation of mRNA: triplet codon2. Translation of mRNA: triplet codon
Amino acid
Gene Expression
Understanding GeneticsUnderstanding Genetics
Relationship between:Relationship between:
GENOTYPE ENVIRONMENT PHENOTYPEGENOTYPE ENVIRONMENT PHENOTYPE
set of genes morphologyset of genes morphology
inherited physiologyinherited physiology
behaviourbehaviour
Interaction of genes and environment
PhenotypeGenotype
Mendelian GeneticsMendelian Genetics
Topics:Topics: - - Transmission of DNA during cell divisionTransmission of DNA during cell division
Mitosis and Meiosis Mitosis and Meiosis (Ch. 4)(Ch. 4)
- Segregation - Segregation (Ch. 5)(Ch. 5)
- Sex linkage - Sex linkage (Ch. 5) (Ch. 5)
- Inheritance and probability - Inheritance and probability (Ch.5)(Ch.5)
- Mendelian genetics in humans- Mendelian genetics in humans
(pedigrees) (pedigrees) (Ch.5)(Ch.5)
- Independent Assortment - Independent Assortment (Ch. 6)(Ch. 6)
- Linkage - Linkage (Ch. 6)(Ch. 6)
- Gene mapping - Gene mapping (Ch. 6)(Ch. 6)
Mendelian GeneticsMendelian Genetics
Topics (cont.):Topics (cont.):
- Tetrad Analysis (mapping in fungi)- Tetrad Analysis (mapping in fungi)
- Extensions to Mendelian Genetics- Extensions to Mendelian Genetics
- Gene mutation- Gene mutation
- Chromosome mutation- Chromosome mutation
- (Quantitative and population genetics)- (Quantitative and population genetics)
Basic Concepts of GeneticsBasic Concepts of Genetics
Cell/nuclear divisionCell/nuclear division
Mitosis (somatic tissue): Mitosis (somatic tissue):
identical cellsidentical cells
Meiosis (germ tissue):Meiosis (germ tissue):
gametes (variation)gametes (variation)
Mendelian Genetics:Mendelian Genetics:ChromosomesChromosomes
Readings:Readings:
Transmission of DNA and cell divisionTransmission of DNA and cell division
- Mitosis and meiosis - Mitosis and meiosis (Ch. 4)(Ch. 4)
pp. 92, 100 – 113pp. 92, 100 – 113
Chromosome Theory of Chromosome Theory of InheritanceInheritance (Ch. 4) (Ch. 4)
- genes organized into chromosomes- genes organized into chromosomes
- correlation: correlation: Genetics & CytologyGenetics & Cytology
- theory can explain the behaviour - theory can explain the behaviour of genes (segregation and of genes (segregation and independent assortment)independent assortment)
Chromosome and DNA Chromosome and DNA ReplicationReplication
1.1. DNA replication results inDNA replication results in
chromosome replicationchromosome replication
2. Nuclear and cell division2. Nuclear and cell division
Haploid (n)
Diploid (2n)
Mitosis
Cell cycle:
S = synthesis
G = “gaps”
2n2n
nn
n = # of chr. in a set
Meiosis
2n2n nn
Animal
eggegg
Polar bodiesPolar bodies
nnnn
Plant
gp = gametophyte
nn
Fungus
Cytological ObservationsCytological Observations
1. 1. Constancy of the number of chromosomConstancy of the number of chromosomeses
2.2. Morphologically similar pairsMorphologically similar pairs (diploid) (diploid)
3. 3. Gametes - contain one set Gametes - contain one set ((haploid)haploid)
2n2n nn
Homologous chromosomesHomologous chromosomes
Two processes of nuclear Two processes of nuclear divisiondivision
1. Mitosis (somatic tissue)1. Mitosis (somatic tissue)
2. Meiosis (germ tissue)2. Meiosis (germ tissue)
MitosisMitosis
1. 1. one parent cell--------> 2 identicalone parent cell--------> 2 identical
daughter cellsdaughter cells
2. same in all organisms2. same in all organisms
3. simple:3. simple:
(a)(a) each chromosome each chromosome
doubles (identical)doubles (identical)
(b)(b) identical halves separate identical halves separate
Four Stages of MitosisFour Stages of Mitosis
1.Prophase1.Prophase
2. Metaphase2. Metaphase
3. Anaphase3. Anaphase
4. Telophase4. Telophase
1. Prophase1. Prophase
- chromosomes condense- chromosomes condense
- 2 chromatids (sister chromatids)- 2 chromatids (sister chromatids)
- centromere- centromere
- nuclear membrane breaks dow- nuclear membrane breaks downn
ChromosomeChromosome
replicationreplication
2. Metaphase2. Metaphase
- chromosomes attach to spindle fibers- chromosomes attach to spindle fibers
- chromosomes migrate to plane between poles- chromosomes migrate to plane between poles
- maximum contraction- maximum contraction: : karyotypekaryotype
- number- number
- centromere position- centromere position
- length- length
Nuclear spindleNuclear spindle
3. Anaphase3. Anaphase
- centromeres divide- centromeres divide
- sister chromatids separate- sister chromatids separate
4. Telophase4. Telophase
- nuclear membrane reforms- nuclear membrane reforms
- spindle disperses- spindle disperses
- cytoplasm divides (cytokinesis)- cytoplasm divides (cytokinesis)
Mitosis:Mitosis: Summary SummaryMitosis:Mitosis:
replicationreplication mitosismitosis
2n = 22n = 2
Mitosis:Mitosis: Summary Summary
replicationreplication mitosismitosis
2n = 42n = 4
Mitosis AnimationMitosis Animation
http://www.whfreeman.com/mga/http://www.whfreeman.com/mga/
Mitosis: Mitosis: LilyLily
Fig. 4-21Fig. 4-21
MeiosisMeiosis(overview)(overview)
diploid (2n) ---------------> haploid (n) gametesdiploid (2n) ---------------> haploid (n) gametes
CChromosome replication hromosome replication once once --------> 2 nuclear --------> 2 nuclear
divisions (meiosis I, divisions (meiosis I, II)II)
one nucleus -------------------> 4 nucleione nucleus -------------------> 4 nuclei
Meiosis I Meiosis IIMeiosis I Meiosis II (reductional) (equational) (reductional) (equational)
Prophase I Prophase IIProphase I Prophase II
Metaphase I Metaphase IIMetaphase I Metaphase II
Anaphase I Anaphase IIAnaphase I Anaphase II
Telophase I Telophase IITelophase I Telophase II
Meiosis I (reductional division)Meiosis I (reductional division)
2n = ?2n = ?Pairing of homologous Pairing of homologous chromosomeschromosomes
Continued Continued
Meiosis II (equational division)Meiosis II (equational division)
4 products 4 products
n = ?n = ?
Meiosis AnimationMeiosis Animation
http://www.whfreeman.com/mga/http://www.whfreeman.com/mga/
Meiosis: Meiosis: Lily Lily pollenpollen
Fig. 4-22Fig. 4-22
Prophase IProphase I
Metaphase IMetaphase I
Anaphase IAnaphase I
Telophase ITelophase I
Prophase IIProphase II
Metaphase IIMetaphase II
Anaphase IIAnaphase II
Telophase IITelophase II
Mitosis MeiosisMitosis Meiosis
somatic cells cells of sexual cyclesomatic cells cells of sexual cycle
one doubling one doublingone doubling one doubling
1 division 1 division 2 cells 2 divisions 2 cells 2 divisions 4 4 cellscells
same amount of DNA ½ amount of DNAsame amount of DNA ½ amount of DNA
Comparison (Fig. 4-24)Comparison (Fig. 4-24)
Mitosis MeiosisMitosis Meiosis
# chrs doesn’t change #chrs. halved# chrs doesn’t change #chrs. halved
No pairing of chr. Synapsis of homologsNo pairing of chr. Synapsis of homologs
Centromeres divide at Centromeres divide at NotNot at anaphase I, at anaphase I,
anaphase but at anaphase IIanaphase but at anaphase II
Conservative VariationConservative Variation
Comparison (continued)Comparison (continued)
Mitosis (n) Mitosis (2n) MeiosisMitosis (n) Mitosis (2n) Meiosis
Fig. 4-20Fig. 4-20
Genetic TerminologyGenetic Terminology
Genes: hereditary elementsGenes: hereditary elements
Alleles: forms of a gene: Alleles: forms of a gene: A , a A , a
b, bb, b++
Genotypes Gene pairsGenotypes Gene pairs
Heterozygote: Heterozygote: Aa bbAa bb++
Homozygotes: Homozygotes: AA aa bb bAA aa bb b+ + bb++
Genes on ChromosomesGenes on ChromosomesExpect behaviour of genes to correlate with Expect behaviour of genes to correlate with the behaviour of chromosomes:the behaviour of chromosomes:
genes chromosomesgenes chromosomes
Diploid (2n) Diploid (2n) AA, Aa, aa pairsAA, Aa, aa pairs
Haploid (n) Haploid (n) A one setA one set
aa
Genes on ChromosomesGenes on Chromosomes
bb+ + bb+ + homozygotehomozygote
Fig. 4-17Fig. 4-17
Genes on ChromosomesGenes on Chromosomes
b bb b+ + heterozygote
b bb b homozygote
Genetic LinksGenetic Linkshttp://www.biology-online.org/tutorials/http://www.biology-online.org/tutorials/2_genetics_evolution.htm2_genetics_evolution.htm
http://www.tokyo-med.ac.jp/genet/mfi-e.htmhttp://www.tokyo-med.ac.jp/genet/mfi-e.htm
http://www.biology.arizona.edu/http://www.biology.arizona.edu/mendelian_genetics/mendelian_genetics.htmlmendelian_genetics/mendelian_genetics.html
http://science.nhmccd.edu/biol/genetics.htmlhttp://science.nhmccd.edu/biol/genetics.html