Genetics Ch. 10

Front 1

The mesoderm can be divided into what 5 components?

Back 1

Lateral mesoderm, intermediate mesoderm, dorsa mesoderm, notochord, head mesenchyme

Front 2

Notochord forms what?

Back 2

The body axis and induces neural tube formation

Front 3

Dorsal mesoderm forms what?

Back 3

Axial skeleton, skeletal muscles, connective tissue of the skin

Front 4

Intermediate mesoderm forms what?

Back 4

kidneys and GI system

Front 5

Lateral mesoderm forms what?

Back 5

Differentiates into the heart, appendicular skeleton, connective tissue of the viscera and body wall, and connective tissues of the amnion and chorion

Front 6

Head mesenchyme forms what?

Back 6

muscles of eyes and head

Front 7

Endoderm forms what?

Back 7

linings of digestive tract, respiratory tree, and pharyngeal pouches

Outgrowths of digestive tract form pancreas, gallbladder, and liver

Respiratory tree forms lungs

Pharyngeal pouches become middle ear, thymus, parathyroid, thyroid

Front 8

What genes are responsible for A/P axis?

Back 8

nodal and Hox family

The A/P axis is defined by the primitive streak and patterned by Hox genes.

Front 9

What genes are responsible for Dorsal/Ventral axis?

Back 9

Noggin and Chordin - encode proteins that dorsalize ventral mesoderm

Bmp-4 - induces ventral fates

Noggin and chordin bind to Bmp-4 to prevent ventralizing

Front 10

Most common genetic cause of human laterality defects?

Back 10

Mutations in zinc-finger protein (ZIC3) of the Gli family

On the X chromosome=
males- randomization
females- reversal

Front 11

Dynein abnormalities?

Back 11

Ciliary dyskinesias

Front 12

PKD1 mutations?

Back 12

leads to polycystin-2 defects which lead to polycystic kidney disease

Front 13

3 ways L/R asymmetry occurs?

Back 13

Unpaired organs develop midline and then lateralize

Asymmetrical outgrowths from midline structures (lungs)

Mirror image paired structure can regress, leaving a lateralized unpaired structure (vessels)

Front 14

Mutations in FGFR genes of cranial mesenchymal fusion?

Back 14

Craniosynostosis- early closure of skull bones

can also be caused by MSX2 mutations

Front 15

Neural crest cells from anterior hindbrain contribute to what?

Back 15

Stapes, Facial cartilage, 2nd pharyngeal pich

Front 16

Neural crest cells from forebrain and midbrain contribute to what?

Back 16

Nasal processes, palate, and mesenchyme for 1st pharyngeal pouch

This mesenchyme becomes:
Maxilla
Mandible
Incus
malleus

Front 17

Cervical neural crest cells contribute to what?

Back 17

mesenchyme of the 3rd, 4th, and 6th pharyngeal arches

These arches become muscles and bones of neck

Front 18

Mutations in GLI3?

Back 18

Greig cephalopolydactyly and Pallister-Hall syndrome

Front 19

Frequency of limb defects?

Back 19

Second only to congenital heart defects

Front 20

Proximal/distal limb growth is dependent on what?

Back 20

Apical Ectodermal Ridge (AER) region of ectoderm

Front 21

r-Fng and Wnt7a function how in limb ventral/dorsal specification?

Back 21

They instruct mesoderm to dorsalize. They are inhibited by Engrailed-1 on the ventral side of the limb.

Ventralization occurs after dorsalization.

Front 22

What stimulates the proliferation of mesodermal cells in the Progress Zone?

Back 22

FGFs

Front 23

Holt-Oram is caused by what mutation? What characterizes the disorder?

Back 23

TBX5
Heart defects (ASD) and bones of the upper limb

Front 24

Ulnar-mammary syndrome from what mutation?

Back 24

TBX3

Front 25

When does gastrulation occur?

What happens during this process and how does it occurs?

Back 25

days 14-28
The embryo in transformed into 3 layers.

Through the invagination of the epiblast in the primative streak.

Front 26

What is neuralation?

Back 26

The formation of the neural tube from the dorsal mesoderm and overlying ectoderm

Initiates organogenesis

Front 27

Hirschsprung's Disease (HSCR) occurs from what?

Back 27

Mutation of neural crest development.

Front 28

Mutations in EDNRB or EDN3 (its ligand) cause what?

Back 28

Hisrchsprung's disease but also can lead to melanocyte abnormalities --> hypopigmented patches of skin and hearing loss=
Waardenburg-Shah syndrome

Front 29

Fibrillin1 mutation?

Back 29

Marfan's syndrome

Front 30

Elastin mutation?

Back 30

Supravalvular aortic stenosis

Front 31

LAMC2 mutation?

Back 31

mutation of encoding laminin; causes JEB (junctional epidermolysis bullosa)

causes blisters on the skin

Front 32

SOX-9 mutations?

Back 32

Skeletal defects like Campmelic dysplasia

and

XY females

Front 33

SOX-10 mutations?

Back 33

A syndrome characterized by Hirschsprung's disease, pigmentatry distrubances, and deafness

Front 34

Gain of function mutation in PTPN11?

Back 34

Noonan syndrome

short, webbing of neck, characteristic facial features, stenosis of pulmonary outflow

Front 35

Mutation of Noggin?

Back 35

excess cartilage forms and fuses bone (synostosis)

effects spine, middle ear, and limbs (esp hands and feet)

Front 36

Homozygosity for WNT3 mutations?

Back 36

Tetra-amelia: absence of all 4 limbs

Front 37

Cysteine to tyrosine substitution in FGFR2?

Back 37

Pleiffer or Crouzon syndrome

Front 38

Glycine to arginine substitution of FGFR3?

Back 38

achondroplasia

short stature, limbs shorter than trunk, macrocephaly

Front 39

FGFR3 activation:
Lesser degree?
Greater degree?

Back 39

Lesser- hypochondroplasia
Greater- Thanatophoric dysplasia (lethal)

Front 40

PAX6 mutation?

Back 40

cataracts and aniridia (absence of the iris)