Flashcards in Devo Lect 16 - Regeneration Deck (15):
2
Which animals can regenerate body parts?
Simpler organisms are the best, hydra, flatworms etc; some crabs and insects can regenerate limbs; mammals and birds hardly at all
3
What are the 4 types of regeneration?
Stem cell mediated regeneration (normal), morphallaxis, epimorphosis, compensatory regeneration
4
Regeneration vs healing
Compare muscle and liver. Muscle doesn’t have significant regeneration (fibrotic scar), but liver can fully regrow.
5
Stem cell mediated regeneration
Ex. blood stem cells, constantly regeneration; natural, not high level; also skin, depends on amount of damage (stem cells can die, can’t grow that fast)
6
Morphallaxis
Hydra and planaria; can form two organisms from two halves; have neoblasts
7
Neoblasts
Used in morphallaxis; Undifferentiated cells spread throughout organism, no apparent function except in wound, migrate to wound site, reform parts of body, totipotent, only need a few
8
Epimorphosis
Stem cells need but not present right away; dedifferentiation
9
Blastema
Develops after initial wound healing; cells turn off differentiated genes and become dedifferentiated, start to grow out and redifferentiate
10
Are blastema cells pluripotent or multipotent?
Chimera study with GFP in cartilage; gave rise to only GFP+ muscle; cells had a “memory” of what they were, therefore multipotent
11
Compensatory Regeneration
Happens in mammalian liver; mostly hepatocytes, proliferate quickly (not normally dividing much)
12
Live liver donor
You can donate 55-70% of your liver and it will grow back in both people in a few months
13
Heart regeneration
In response to damage (overworked, heart attack); in humans, cells grow bigger to compensate for dying cells but not as good; scarring occurs if cut too
14
Zebrafish heart regeneration
First undergoes wound formation, then proliferation, then wound healing; more so compensatory, no blastema formation!
15
BrdU
Bromodioxy uridine; Analog of uracil, incorporated into cells during S phase, shows that cells are dividing
16