growth and cancer

Question 1

String

Answer 1

controlled by gap genes, pair rule genes, segment polarity genes etc.
phosphatase activating CDKs
controls cell cycle program

Question 2

how and why does mesoderm express string and not divide?

Answer 2

how? - tribbles blocks string

why? - mesoderm invaginates into embryo to form mesoderm germ layer + as soon as cell divides it cannot move

Question 3

experiment showing there is intrinsic control of organ size

Answer 3

graft limb bud of donor newt onto host newt
host newt is smaller. observe grafted limb = larger than limbs from host newt
- intrinsic growth pattern = maintained

Question 4

rapamycin

Answer 4

TOR pathway inhibitor

Question 5

what are the 2 growth control pathways and what do they do?

Answer 5

TOR pathway - controls cell size

Hippo pathway - controls organ size by blocking growth

Question 6

what activates the Hippo pathway?

Answer 6

a lot of cell-cell contacts —> blocks growth

Question 7

what inactivates the Hippo pathway?

Answer 7

mechanical stress = cell stretch b/c not enough cells around —-> drives growth

Question 8

what is the vertebrate homolog of Hippo?

Answer 8

Mst1/2

Question 9

how does IGF affect growth?

Answer 9

drives increase in size + ageing

Question 10

describe the process of molting

Answer 10

1. stretch receptors on epidermis detect stretch
2. PTTH (hormone) activated
3. drives ecdyson expression in protothoracic gland
4. drives molting

Question 11

PTTH

Answer 11

release of ecdyson from protothoracic gland

Question 12

juvenile hormone

Answer 12

prevents metamorphosis

Question 13

Describe the process of metamorphosis from tadpole to a frog

Answer 13

1. environmental cues act on hypothalamus
2. hypothalamus releases corticotropin releasing hormone
3. CRH causes production of thyroid stimulating hormone production from pituitary gland
4. TSH causes production of thyroxin
5. metamorphosis

Question 14

Li Fraumeni

Answer 14

LOF p53 mutation