Pedigree Charts
description
Transcript of Pedigree Charts
Pedigree ChartsPedigree Charts
The family tree of geneticsThe family tree of genetics
Pedigree ChartsPedigree Charts
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OverviewOverview
I.I. What is a pedigree? What is a pedigree? a.a. DefinitionDefinition
b.b. UsesUses
II.II. Constructing a pedigree Constructing a pedigree a.a. SymbolsSymbols
b.b. Connecting the symbolsConnecting the symbols
III.III. Interpreting a pedigree Interpreting a pedigree
What is a Pedigree?What is a Pedigree?
A pedigree is a chart of the genetic A pedigree is a chart of the genetic history of family over several history of family over several generations.generations.
Scientists or a genetic counselor would Scientists or a genetic counselor would find out about your family history and find out about your family history and make this chart to analyze.make this chart to analyze.
Constructing a PedigreeConstructing a Pedigree
MaleMale
FemaleFemale
Connecting Pedigree SymbolsConnecting Pedigree Symbols
Fraternal twinsFraternal twins
Identical twinsIdentical twins
Examples of connected symbols:Examples of connected symbols:
Connecting Pedigree SymbolsConnecting Pedigree Symbols
Married CoupleMarried Couple
SiblingsSiblings
Examples of connected symbols:Examples of connected symbols:
ExampleExample
What does a pedigree chart look like?What does a pedigree chart look like?
Symbols in a Pedigree ChartSymbols in a Pedigree Chart
Affected Affected X-linkedX-linkedAutosomal Autosomal
carriercarrierDeceasedDeceased
Interpreting a Pedigree ChartInterpreting a Pedigree Chart
1.1. Determine if the pedigree chart shows an Determine if the pedigree chart shows an autosomal or X-linked disease.autosomal or X-linked disease.
– If most of the males in the pedigree are If most of the males in the pedigree are affected the disorder is X-linked affected the disorder is X-linked
– If it is a 50/50 ratio between men and If it is a 50/50 ratio between men and women the disorder is autosomal.women the disorder is autosomal.
Example of Pedigree ChartsExample of Pedigree Charts
Is it Autosomal or X-linked?Is it Autosomal or X-linked?
AnswerAnswer
AutosomalAutosomal
Interpreting a Pedigree ChartInterpreting a Pedigree Chart
2.2. Determine whether the disorder is Determine whether the disorder is dominant or recessive.dominant or recessive.
– If the disorder is dominant, one of If the disorder is dominant, one of the parents must have the disorder.the parents must have the disorder.
– If the disorder is recessive, neither If the disorder is recessive, neither parent has to have the disorder parent has to have the disorder because they can be heterozygous.because they can be heterozygous.
Example of Pedigree ChartsExample of Pedigree Charts
Dominant or Recessive?Dominant or Recessive?
AnswerAnswer
DominantDominant
Example of Pedigree ChartsExample of Pedigree Charts
Dominant or Recessive?Dominant or Recessive?
AnswerAnswer
RecessiveRecessive
SummarySummary
Pedigrees are family trees that Pedigrees are family trees that explain your genetic history.explain your genetic history.
Pedigrees are used to find out the Pedigrees are used to find out the probability of a child having a probability of a child having a disorder in a particular family.disorder in a particular family.
To begin to interpret a pedigree, To begin to interpret a pedigree, determine if the disease or condition determine if the disease or condition is autosomal or X-linked and is autosomal or X-linked and dominant or recessive.dominant or recessive.
Pedigree Chart -Cystic FibrosisPedigree Chart -Cystic Fibrosis
Human GeneticsHuman Genetics
KaryotypeKaryotype
Chromosome NumberChromosome Number
Different # for Different # for different speciesdifferent species
Full setFull set = = 2N=2N=DiploidDiploid
N=N= # pairs# pairs 1 pair from mother1 pair from mother 1 pair from father1 pair from father Humans= Humans= 23 pairs23 pairs or or 46 total46 total
Homologous Chromosomes are the sets of each pair
Autosomes & Sex Autosomes & Sex ChromosomesChromosomes
Autosomes = # 1-22 for all traits except sex
Sex chromosomes= Pair # 23 XX(female) orXY(male)
Down Syndrome= 3 of #21Down Syndrome= 3 of #21
KlinefelterKlinefelter’’s = XXYs = XXY
Multiple AllelesMultiple AllelesMore than More than one type one type of allele of allele for a traitfor a trait
Example:Example:
Blood TypeBlood Type
TYPES:TYPES:
A A IIAAIIAA, I, IAAii
B B IIBBIIB B , I, IBBii
AB AB IIAAIIBB
O O iiii
MutationMutation ChangeChange in DNA in DNA
codecode Caused by:Caused by:
1.1. Chemical Chemical damagedamage
2.2. Errors in Errors in ReplicationReplication
3.3. X-ray damageX-ray damage
4.4. UV damageUV damage
ATGC
Ato A G C
MutationMutationChanges in the Changes in the
DNA code DNA code = Changes in = Changes in
the final the final proteins madeproteins made
=Changes in =Changes in the organismthe organism
Genetic Genetic TechnologyTechnology
Recombinant DNA &Recombinant DNA &Bacterial TransformationBacterial Transformation
1. Transgenic tobacco plant?1. Transgenic tobacco plant?
Genetically Genetically engineeredengineered
Inserting fire Inserting fire fly genes fly genes into the into the plantplant
Using Using ““cut & cut & pastepaste”” enzymesenzymes
2. Genetic Engineering:2. Genetic Engineering:
Altering the genetic makeup Altering the genetic makeup of an organismof an organism
By Cutting DNA from one By Cutting DNA from one organism and inserting organism and inserting fragments into a hostfragments into a host
Recombinant DNARecombinant DNAAlters the allele frequency of Alters the allele frequency of
a population by artificial a population by artificial meansmeans
Recombinant DNA:Recombinant DNA:
““RecombineRecombine””Connecting or Connecting or
reconnecting DNA reconnecting DNA fragmentsfragments
DNA of two different DNA of two different organismsorganisms
Example: lab of inserting human DNA Example: lab of inserting human DNA into bacteriainto bacteria
Genetic Engineering of InsulinGenetic Engineering of InsulinHuman DNA cut out
Human DNA put into bacteria DNA
Bacteria DNA is opened up Many BacteriaGrow humaninsulin
4. Transgenic Organism:4. Transgenic Organism:““transtrans”” = across = across““genicgenic”” = race = raceContains genes from Contains genes from
another organismanother organismBacteriaBacteriaVirusVirusHumanHuman
5. Tobacco Recombinant DNA 5. Tobacco Recombinant DNA Process:Process:
a.a. Isolated DNA to be Isolated DNA to be inserted into hostinserted into host
b.b. Attach DNA fragment to a Attach DNA fragment to a vehicle (vector)vehicle (vector)
c.c. Transfer the vector to the Transfer the vector to the host=host=
Transgenic organismsTransgenic organisms
Restriction Enzymes:Restriction Enzymes:
Restriction Enzymes cut DNA at very specific sites Separate the base pairs of both strands“Scissors” in Recombinant DNA
Human Cut Bacterium DNA cut
7. 7. ““Sticky endsSticky ends””DNA cuts that have DNA cuts that have singlesingle
stranded endsstranded endsAttract corresponding base Attract corresponding base
pairspairsMade by special restriction Made by special restriction
(cutting) enzymes(cutting) enzymes
GGCCATTACCCGC TACCGG
TAATGATGGCStick together
Vectors = vehiclesVectors = vehiclesCarry foreign DNA Carry foreign DNA fragments into the hostfragments into the host
Bacteria carried the firefly Bacteria carried the firefly DNA into the tobacco cellsDNA into the tobacco cells
Biological orBiological orMechanicalMechanical
Vectors:Vectors:
Biological:Biological:VirusVirusBacterial Bacterial plasmid plasmid (circular (circular DNA)DNA)
Mechanical:Mechanical:MicropipettMicropipettee
Metal bullet Metal bullet coated with coated with DNADNA
Recombinant DNA Uses:Recombinant DNA Uses: Grow human Grow human
hormones in hormones in bacteria culturesbacteria cultures
Artificial Artificial sweeteners using sweeteners using bacteria to make bacteria to make amino acidsamino acids
Study human Study human diseases by diseases by inserting human inserting human DNA into miceDNA into mice
Replace incorrect Replace incorrect DNA sequencesDNA sequences
Replace harmful Replace harmful bacteria on bacteria on plantsplants
Nitrogen bacteria Nitrogen bacteria in the soil & in the soil & plants to make plants to make fertilizerfertilizer
Improve Improve transport of fruitstransport of fruits
Resist diseasesResist diseases Increase protein Increase protein
productionproduction