Regeneration

Question 1

What are the two types of regeneration?

Answer 1

morphallaxis
epimorphosis

Question 2

Morphallaxis

Answer 2

regeneration without any growth

Question 3

Epimorphosis

Answer 3

regeneration involving extensive cell proliferation of somatic cells

Question 4

How do hydra regenerate morpholaxicallly?

Answer 4

they grow continuously so cells have to change their positional values
repatterning occurs in reproduction

Question 5

How do urodele regenerate epimorphically?

Answer 5

epidermal cell migration
cells below differentiate to form blastema
multi-nucleate cells have to break apart
cells stay true to type

Question 6

Limb regeneration

Answer 6

distal to the wound
cells stay true to type

Question 7

Newt anterior gradient

Answer 7

protein that can replace the nerve supporting outgrowth, expressed in nerve sheath in response to wounding
binds prod1

Question 8

Mammalian regeneration

Answer 8

young children and mice can regenerate the tips of digits

Question 9

PNS regeneration

Answer 9

regrowth of axons but not neurons
schwann cells must be present for this

Question 10

CNS regeneration

Answer 10

very little regeneration as there is a non-permissive environment due to glia, astrocytes and oligodendrocytes
schwann cells can promote axon growth

Question 11

Vertebrate heart regeneration

Answer 11

cardiomyocytes are present but dont divide, which causes scar or maladaptive hypertrophy

Question 12

Ventricular regeneration in zebrafish

Answer 12

not the same as embryonic development
dependent on dedifferentiating muscle cells, neuregulin may be involved as a signal from the epicardium
mps1 important in balance between scarring and regeneration