Evolutionary change

do evolutionary changes happen in gene expression or mutations in protein sequences

gene expession

what causes most evolutionary changes in gene expression

cis-regulatory elements

evidence of cis-regulatory mutations driving evolutinary change

stickleback fish, D. biarmipes, and galapagos finches

what is the cis-regulatory mutation of the stickleback fish

mutation in a single enhancer for the Pitx1 gene, alters its expression in hindlimbs, resulting in morphological differences in different species

what is the cis-regulatory mutations of the D. biarmipes

has a unique pigmented spot on its wing that is not present in other closely related species. uses wing spot during mating. changes in expression of the Yellow gene are responsible for differences in wing pigmentation. Gain of Yellow expression in biarmipes caused by mutation that created new binding site for pink activator in enhancer for Yellow

what is the cis-regulatory mutation of the galapagos finches

changes in BMP expression responsible for differences in beak size/shape

types of regeneration

stem cell mediated, epimorphosis, morphallaxis, and compensatory regeneration

stem cell mediated regeneration

stem cell population drives regrowth of certain tissues

stem cell mediated regeneration example animal

flatworm

epimorphosis

adult cells de-differentiate then re-differentiate to form new structures

epimorphosis example animal

salamander

morphallaxis

no growth of new tissues, re-pattering of existing cells

compensatory regeneration

differentiated cells can divide to replace cells of same time

compensatory regeneration example animal

human liver

how many pieces can a flatworm be cut into and still regenerate

279

clonogenic neoblasts

stem cell populations in flatworms

how many stem cells is required to repair damage in flatworms

one

what maintains pluripotency in flatworm stem cells

Ncoa5, a translational regulator enriched in neoblasts. also follistatin, piwi, and tudor

What do you think would happen if you chopped off the tail of a flatworm, and added a Wnt inhibitor during regeneration?

if the tail is removed and Wnt is induced, then the removed half would develop into anterior fates instead of posterior ones, resulting in a double headed flatworm

how much of the liver can be removed and still regrow

¾ can be removed

what might induced pluripotent stem cells be able to treat

Parkinson's, macular degeneration, heart disease/damage, osteoarthritis, diabetes, and more