molecular reg of development-theisen

Question 1

growth and differentiation factors

Answer 1

FGFs- fibroblast growth factors
hedgehog proteins-desert, indian and sonic
transforming growth factor beta (TGF-beta)- superfamily
-bone morphogenetic proteins (BMP)
WNT proteins

Question 2

transcription factors

Answer 2

HOX genes and homeodomain proteins
T-box gene family
Helix-loop-helix
zinger finger proteins
-sox genes
-WT1

Question 3

Hox genes

Answer 3

39 homologous in 4 clusters on 4 chromosomes. play prominent role in craniocaudal segmentation of the body. 3’ genes expressed earlier than 5’

Question 4

Hox gene regulation

Answer 4

a bunch of retinoic acid (Vitamin A derivative, acutane) screws up the body

Question 5

mutations in hox genes

Answer 5

loss of function=posterior to anterior transformations

gain of function=anterior to posterior transformations

Question 6

Pax gene family

Answer 6

9 known members. critical role in formation of tissues and organs during embryonic development, and normal function of certain cells after birth.

Question 7

Pax gene disorder

Answer 7

aniridia (complete or partial absence of iris)

Question 8

lim proteins

Answer 8

involved in formation of virtually all body segments.

absence of certain proteins results in headless mammilian embryos

Question 9

Dlx genes

Answer 9

6 members, important role in patterning of outgrowing appendages in early embryogenesis, and morphogenesis of the jaws and inner ear

Question 10

Msx genes

Answer 10

6 types in humans. Prenatally-general inhibitors of cell differentiation.
postnatally-maintain proliferative capacity of tissues.
involved in epithelial-mesenchymal interactions in face and limbs

Question 11

Msx disease

Answer 11

craniosynostosis (fusion of skull where it shouldnt)

Question 12

t-box genes (Tbx)

Answer 12

100 (18) in humans. important in mesodermal germ layer development and in specifying whether limbs will be forelimb or hindlimb

Question 13

Helix-loop-helix transcription factors

Answer 13

2 alpha-helices separated by a short amino acid loop with adjacent basic regions. Common in tf’s that regulate myogenesis (formation of muscle tissue)

Question 14

Fox gene family (forkhead)

Answer 14

over 100 members. regulate the expression of genes involved in cell growth, proliferation, differentiation and longevity. Have pioneering transcription activity by binding condensed chromatin during cell differentiation. (winged helix is forkhead box)

Question 15

FOXP2

Answer 15

positive selection. first gene associated with disorders of speech and lang. development.

Question 16

Zink finger proteins (TF)

Answer 16

regulate myogenesis, implicated in bone, cartilage, or tooth development. zink deficiency is known to result in growth retardation and pathogenesis of osteoporosis.

Question 17

SOX genes

Answer 17

greater than 20 members. SoxA=SRY, sex determining region of Y chromosome. zinc finger TF

Question 18

SOX9 gene mutation

Answer 18

campomelic dysplasia. Short legs, dislocated hips, underdeveloped shoulder blades, 11 pairs of ribs, bone abnormalities in the neck and clubfeet. Ambiguous genitalia. Laryngeotracheal malacia (softened cartilage in respiratory system). zinc finger TF

Question 19

WT1

Answer 19

wilm’s tumor suppressor gene. plays a role in kidney and gonadal development. Zinc finger TF

Question 20

FGFs (fibroblast growth factors)

Answer 20

associated with ECM and must bind to heparan sulfate to activate receptors. Involved in angiogenesis, wound healing, embryonic development, and endocrine pathways

Question 21

SHH- Sonic hedgehog protein

Answer 21

regulation of vertebrate organogenesis, facial and limb patterning and organization of the brain. Controls division of adult stem cells

Question 22

IHH- indian hedgehog

Answer 22

chondrocyte differentiation, proliferation and maturation esp. during endochondral ossification

Question 23

DHH- Desert hedgehog

Answer 23

defects associated with partial gonadal dysgenesis (PGD) accompanied by polyneuropathy

Question 24

Hedgehog proteins

Answer 24

binds to patched receptor (PTCH) which is bound to transmembrane protein (smoothened. SMO)

Question 25

Wnt

Answer 25

gastrulation and organogenesis. Also interacts with ECM components and cell-cell interactions during embryogenesis. signal is transduced by beta-catenin

Question 26

Wnt signal member APC

Answer 26

colorectal cancer