19 Developmental Genetics Flashcards

1
Q

What is needed for an organism to grow form a single cell?

A

Differential gene expression

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2
Q

What are the 4 developmental patterns that can be gained from animal models?

A

Axis specification. Pattern formation. Organogenesis. Induction/polarity

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3
Q

What are the six animal models mentioned and their scientific names?

A

C.elegans(nematode) D.melanogaster(fruit fly) D.rerio(zebrafish) X.laevis(clawed frog) G.gallus(chicken) M.musculus(mouse)

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4
Q

Pro/con of C.elegans model

A

Short generation, know cell fate/invertebrate

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5
Q

Pro/con of D.melanogaster model

A

Short gen, easy breeding, high mutation/maintenance

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6
Q

Pro/con of D.rerio model

A

Transparent embryo, easy breeding/small embryo

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7
Q

Pro/con of X.laevis model

A

Large embryo/tetraploid

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8
Q

Pro/con of G.gallus model

A

Large embryo/genetics difficult (genome is mapped now however)

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9
Q

Pro/con of M.musculus model

A

Easy breeding, mammal/embryo small

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10
Q

Which genetic mediators interact between nearby cells?

A

Paracrine signaling molecules

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11
Q

Which genetic mediators control gene expression and respond to external stimuli?

A

DNA transcription factors

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12
Q

Which genetic mediators facilitate migration and is scaffolding?

A

Extracellular Matrix proteins

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13
Q

What are the four mentioned paracrine signaling molecules?

A

Fibroblast Growth factor(FGF), Hedgehog proteins, Wingless family(Wt), Transforming growth factor beta(TGF-beta)

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14
Q

What can be affected in paracrine signaling mutations?

A

Receptor or molecule

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15
Q

What expresses FGFR3?

A

Growing bones

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16
Q

What results from FGFR mutations?

A

Autosomal dominant, skeletal dysplasias depending on how severe

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17
Q

What are the three forms of FGFR3 mutation phenotypes?

A

Achondroplasia - most common, short limbs, microcephaly // hypochondroplasia - milder form // thanatophoric dysplasia - lethal, very short limbs, receptor highly activated

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18
Q

What are the three mentioned transcription factors mentioned?

A

Homeobox - HOX //High mobility group - SOX // T-box - TBX

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19
Q

What is the archetype of the SOX family

A

SRY gene of Y -> regulates SOX9, high in males, low in females, mammalian testis determining factor

20
Q

What does SOX9 regulate? What will mutation do?

A

Chondrogenesis and Col2A1. Mutation = camptomelic dysplasia = short limbs, female XY

21
Q

What is Hirschsprung diseases and what gene of the SOX family can cause it?

A

Neural crest defect causing colon hypomobility, males 4x risk, SOX10 mutation

22
Q

What are the four main ECM proteins mentioned?

A

Collagens, fibrilins, elastin and laminin

23
Q

What disease results from Type I collagen gene mutation?

A

Osteogenesis imperfecta due to mutation in glycine within fibrils = bone disruptions mild to lethal

24
Q

What can a mutation of Fibrillin 1 and elastin cause?

A

Marfan’s syndrome leading to heart and large blood vessel problems along

25
Q

What are the phenotypic results of marfans?

A

Tall/lanky, arachnodactyly, lens displacement

26
Q

What can a mutation of laminin gene LAMC2 cause?

A

Junctional epidemoylysis bullosa leading to large blisters on the skin

27
Q

What is the function of laminin?

A

Anchors cells to ECM

28
Q

What is pattern formation?

A

How tissues and organs are established thus position and cell differentiation

29
Q

What processes is Sonic Hedgehog SHH gene involved in?

A

Neural tube/somite/limbs and the left-right axis

30
Q

What is cell fate?

A

Type, fxn and longevity

31
Q

What results form a severe defect in SHH gene cause?

A

Midline brain development leading to holoprosencephaly

32
Q

What does the SHH bind to?

A

Membrane Cholesterol

33
Q

Which genes are the axes of the body determined by?

A

4 clusters of put to 13 genes = 39 total HOX genes

34
Q

genes in the same relative position (ie. HOX) are called?

A

Paralogs

35
Q

Define temporal colinearity and spatial colinearity

A

Temporal - genes on the 3’ end will be expressed sooner//Spatial - genes on the 3’ will be expressed more at the “front”(anterior) of the protein sequence

36
Q

Define Homeotic transformation

A

When HOX genes are not in correct sequence/combination -> affected area transforms to another part

37
Q

What signals define the Ventral axis? Dorsal? Lateral?

A

Ventral - Bmp4 // Dorsal - Noggin, Chordin binds off Bmp4 // Lateral - equal amounts of SHH

38
Q

Laterality defects can cause what two anomalies?

A

Situs ambiguus or situs inversus

39
Q

With a ZIC3 protein what may occur in males and females?

A

Males - situs ambiguus // females - situs inversus

40
Q

Which is a candidate gene for limb induction and what maintains its expression?

A

FGF8 of the mesoderm induces, WNT2b/8c maintains its expression

41
Q

Growth of the limb bud is stimulated by which three signals?

A

FGF2/4/8

42
Q

The zone of polarizing activity(ZPA) uses what to maintain the apical ectodermal ridge?

A

SHH

43
Q

What is a typical anterior axis defect, signs and gene affected?

A

Holt-Oram syndrome leading to shortened or missing radius and thumbs. T-box gene TBX5 is mutated

44
Q

What is a typical posterior axis defect, signs and gene affected?

A

Ulnar mammary leading to deformed upper limbs and chest on the ulnar side. TBX3 gene (related to TBX5) is responsible

45
Q

What gene drives pancreatic development, maturation, differentiation as well as insulin release?

A

IPF1

46
Q

What are two animal models used commonly to test specific genes as well as its effect upon deletion?

A

Transgenic and knockout mice