+ All Categories
Home > Documents > Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new...

Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new...

Date post: 21-Dec-2015
Category:
View: 238 times
Download: 0 times
Share this document with a friend
Popular Tags:
53
Lecture 29 Inheritance
Transcript
Page 1: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Lecture 29

Inheritance

Page 2: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Importance of geneticsImportance of genetics• Understanding hereditary diseases and to Understanding hereditary diseases and to

develop new treatmentsdevelop new treatments• Donor matchesDonor matches• PaternityPaternity• ForensicsForensics• EvolutionEvolution

Page 3: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Genetic TestingWould you want to know?

• Ethical concerns• Cost• Insurance companies

Page 4: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Difference between Meiosis and MitosisDifference between Meiosis and Mitosis

Page 5: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Meiosis IMeiosis I

Interphase Prophase I Metaphase I Anaphase I Telephase I

Page 6: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Crossing Over of Nonsister Chromatids between Homologous Chromosomes

Page 7: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Meiosis IIMeiosis II

Prophase II Metaphase II Anaphase II Telephase II

Page 8: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.
Page 9: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Genetic Testing

Page 10: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Gel electrophoresis

Page 11: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

• PCR way of copying specific DNA fragments from small sample DNA material "molecular photocopying"

• It’s fast, inexpensive and simple

Polymerase Chain Reaction

Page 12: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.
Page 13: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Genetic Testing

Paternity Test $99

$299, looks at specific diseases

23 and me

Page 14: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

• Genes- genetic material on a chromosome that codes for a specific trait

• Genotype- the genetic makeup of the organism

• Phenotype- the expressed trait• Allel- an alternative form of a

gene

Genetic Definitions

Page 15: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Dominance Mechanism

• Two alleles are carried for each trait

• In true-breeding individuals, both alleles are the same (homozygous).

• Hybrids, on the other hand, have one of each kind of allele (heterozygous).

• One trait is dominant, the other trait is recessive

Page 16: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Homunculus

How is “heredity passed on:

Spermist vs Ovists

Spermist conception of a

human sperm

Page 17: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Homunculus

Leeuwenhoek’s black male and white female rabbit experiments: spermist “proof”

Page 18: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Mendel’s Three Principles

• Dominance

• Segregation

• Independent Assortment

The foundation of “classical” scienceThe foundation of “classical” science

(1822-1884)

Page 19: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Dominance

• Traits of both parents inherited, but one shows over the other

• Traits are not blended

Page 20: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Dominance Mechanism

• Two alleles are carried for each trait

• In true-breeding individuals, both alleles are the same.

• Hybrids, on the other hand, have one of each kind of allele.

• One trait is dominant, the other trait is recessive

Page 21: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Segregation

• Half the gametes (egg or sperm) will carry the traits of one parent and half the traits for the other parent

Pairs of alleles are separated (=segregated) during meiosisPairs of alleles are separated (=segregated) during meiosis

Page 22: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Two different parental characteristics will be inherited independently of one another during gamete formation.

Independent Assortment

Example: flower color and leaf shape

Page 23: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Genetic Information

Genes are traits

“Eye color”

Ear lobe connectedness

Genes produce proteins

Enzymes are proteins

Page 24: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Homologous Chromosomes

gene: location

allele: specific trait

Page 25: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Allele Example

Gene = “eye color”

Alleles

brownbluegreenlavender

Page 26: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Allele Examples

appearance

eye color:homozygous

Page 27: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Allele Examples

appearance

eye color:heterozygous,brown dominant over blue

Page 28: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Genotype vs Phenotype

homozygous(dominant)

heterozygous

homozygous(recessive)

genotype phenotype

appearanceappearance

Page 29: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Punnett Square

If male & female are heterozygous for eye color

X

brown: 3/4 offspringblue: 1/4 offspring

male

female

Page 30: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

PKUEach parent carries one gene for PKU.

P p

P pX

P

p

pP

P

P

P

p

p

P

p

p

Possible genotypes: 1PP 2Pp 1pp

Possible phenotypes:no PKU PKU

Page 31: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Compare this to what would have happened if one parent was homozygous for sickle cell.

HbA HbA

HbS HbS

X

HbS

HbS

HbAHbA

HbA

HbS

HbA

HbS

HbS

HbA

HbS

HbA

all offspring are carriers of sickle cell trait

Page 32: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Where Does Genetic Diversity Come From?

Where Does Genetic Diversity Come From?

• Mutation• Chromosomal Aberrations• Genetic Recombination

(e.g., from sexual reproduction)

• Mutation• Chromosomal Aberrations• Genetic Recombination

(e.g., from sexual reproduction)

Page 33: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

mutationmutation

Sickle Cell Mutation

CTG ACT CCT GAG GAG AAG TCTLeu Thr Pro Glu Glu Lys Ser

CTG ACT CCT GAG GTG AAG TCTLeu Thr Pro Glu Val Lys Ser

NORMAL Hb

SICKLE CELL

Page 34: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Autosomes and Sex Chromosomes

Page 35: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Red-Green Color BlindnessSex-linked trait

XC Y

XC Xc

X

XC

Xc

YXC

XC

XC

XC

Y

Xc

XC

Y

Xc

Normal male

Normal female recessive gene

Possible outcomes: XCXC XCXc XCY XcYNormal female

Normal Female(carrier)

Normal male

Color-blind male

Page 36: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

E unconnected earlobee connected earlobeE unconnected earlobee connected earlobe

alleleallele genegene

P EE x ee

gametes E e

F1 Ee

unconnected

connected

Page 37: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

F1 Ee x Ee

gametes1/2 E 1/2 e1/2 E 1/2 e

E

e

E e

EE Ee

Ee ee

F2 1 EE 2 Ee 1 ee

PunnettSquare

Page 38: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Genotypes Phenotypes

Experiment to determinedominant vs. recessiveExperiment to determinedominant vs. recessive

Page 39: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Genetic Sleuthing

My eye color phenotype is brown.

What is my genotype?

Page 40: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Complexities

• Multiple genes for one trait

• Example: eye color

• Blended traits (“incomplete dominance”)

• Influence of the environment (UV, smoking, alcoholism)

Page 41: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Complexities

• Co-dominance-neither allele is recessive and the phenotypes of both alleles are expressed.

• Blood types- AB (not O); sickle cell anemia

heterochromia

Page 42: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Disorders

Down’s Syndrome (chrom 21)

Huntington’s (chrom 4)

Alzheimer’s (chrom 1, 10, 14, 19, 21)

Page 43: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.
Page 44: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Tongue RollerTongue Roller

R = Tongue Rollerr = Unable to Roll Tongue

Page 45: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Widow’s Peak

W = Widows Peakw = Lack of Widow’s Peak

Page 46: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Free Ear Lobe Attached Ear Lobe

E = Free Ear Lobee = Attached Ear Lobe

Page 47: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Hitchhiker’s Thumb

Hi = Straight Thumbhi = Hitchhiker’s Thumb

Page 48: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Bent Little FingerBent Little Finger

Bf = Bent Little Fingerbf = Straight Little Finger

Page 49: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Mid-digital Hair

M = Mid-Digital Hairm = Absence of Mid-Digital Hair

Page 50: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Dimples

D = Dimplesd = Absence of Dimples

Page 51: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Short Hallux

Ha = Short Halluxha = Long Hallux

Page 52: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

Short Index Finger

Ss = Short Index FingerS1 = Long Index Finger

*Sex-Influenced Trait*Sex-Influenced Trait

Page 53: Lecture 29 Inheritance. Importance of genetics Understanding hereditary diseases and to develop new treatmentsUnderstanding hereditary diseases and to.

http://www.youtube.com/watch?v=gCPuHzbb5hA


Recommended