bimm 110 section 3 slides

8/14/2019 BIMM 110 Section 3 Slides

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G. Chen 2009. Slide 1

BIMM 110 Section 3IMM 110 Section 3George Chen

[email protected]

OH: Tu 12:30-1:30p Sierra Summit

4747DAYS UNTILDAYS UNTIL

FINALFINAL
mailto:[email protected]:[email protected]


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Questions from last sectionQuestions from last section

How does a male's X chromosome know notto inactivate?

In Kleinfelter's and Triple-X syndrome, arethe extra X chromosomes inactivated?


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Nondisjunction related geneticNondisjunction related genetic

diseasesdiseases Autosomal

Monosomy

None viable Several partial deletions

Trisomy

21 Down's Syndrome

13 Patau Syndrome 18 Edwards Syndrome


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Nondisjunction and maternal ageNondisjunction and maternal age

Possible theory explaining increased risk ofnondisjunction related to maternal age is thatconstant hormone exposure somehownegatively affects premature eggs.



Down Syndrome and ADDown Syndrome and AD

Alzheimer's Disease is caused by amyloidprecursor protein (APP) accumulated inamyloid-beta deposits and tau proteinsaccumulated in neurofibrillary tangles

Downs patients have excessive amounts ofAPP, leading to early onset AD

APP gene is on chromosome 21



Patau SyndromePatau Syndrome

Severe mental retardation

Small eyes, split in iris

Cleft palate Weak muscle tone

Increased risk of heart defects



Edwards SyndromeEdwards Syndrome

Heart defects

Kidney problem

Developmental delays



Sex RelatedSex Related

Monosomy

XO Turner's

YO ?? Disomy

XY Female, XX Male

Trisomy XXY Kleinfelter's

XYY

XXX Triple X



TurnersTurners

No mental retardation

Congenital heart disease

Kidney problems Infertile

Treated with growth hormone


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PARsPARs

Pseudoautosomal regions found at tips of Xand Y chromosomes

Mutant SHOX have shorter stature 2 copies of SHOX required for proper height

development


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XX Male, XY FemaleXX Male, XY Female

Treated with hormone replacement

Caused by deletions, crossing over


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Kleinfelter's (XXY)Kleinfelter's (XXY)

IQ from well below to well above average

Behavioral problems

Hypogonadism, hypogenitalism Treated with testosterone replacement


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XYYXYY

Fertile, will give birth to normal offspring

Normal IQ

Behavioral problems once thought linked todelinquency


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XXXXXX

Fertile, will give birth to normal offspring

Quiet

Delayed development


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Sex differentiationSex differentiation

Mesonephric duct= Wolffian duct

Paramesonephricduct = Mullerianduct

Requires Y

chromosome fordifferentiation


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Sex DifferentiationSex Differentiation

SRY (Sex determining region Y) encodes fora protein TDF (Testes determining factor)

Production of testosterone leads todevelopment of male genitalia

Production of Mullerian Inhibiting Substancefrom Sertoli cells inhibits Mullerian ducts from

developing into female genitalia Default pathway is female


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Gamete formationGamete formation

Spermatogenesis

Oogenesis


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FertilizationFertilization

Sperm acrosome releasesHyleuronidase, an enzyme tobreak down the 'glue' holding thecorona radiata together

Sperm wedges into zonapellucida, binds to ZP3 receptor

Acrosome contents exocytosed,zona pellucida locally brokendown

Fusion of acrosome and eggcauses fusion of cortical granulesto membrane preventingpolyspermy


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InfertilityInfertilityIn MALES Low sperm count

Poor sperm health

In FEMALES

Structural problems Scarring/blockage

Absence of structures

Functional problems

Non functional ovaries

Endometriosis

Shared problem

Woman has antibodies against partners sperm


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Artificial Reproductive TechniquesArtificial Reproductive Techniques

In Vitro Fertilization

Zygote Intrafallopian Transfer

Gamete Intrafallopian Transfer Intracytoplasmic Sperm Injection

bimm 110 section 3 slides

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