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BMS242 - Cell and Molecular > Genome Evolution > Flashcards

Flashcards in Genome Evolution Deck (10)
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What is the molecular clock?

The change in nucleotide sequence that occurs at about 1% every 10 million years


How is the molecular clock calibrated?

Using fossil records


What are the positions in which mouse and chimps or chimps and humans share on the FOXP2 gene?

Mouse and chimp - 303T
Chimp and human - 80D


What is convergent evolution?

Where organisms not closely related inherit similar traits as a result of having to adapt to similar ecological niches


What are the 4 clusters that the 22 FGFs fall into based on?

Protein sequence alignment


How do many FGFs arise?

Gene duplication


Describe chromosome duplication

Duplicate genes are initially redundant. The extra copy can change in pattern of expression or structure of the protein. Small changes are caused by point mutations and big changes are caused by domain swapping.


Enhancers are easily changed, T or F?



What is the evidence that a new enhancer closer to the gene changes function?

1. C6 Hox gene expression starts posterior in chick = longer neck and less chest than mouse
2. Changing expression of a single gene creates ectopic organs. Master regulatory genes regulate whole gene networks - crustaceans have legs on abdomen, insects only have on thorax. Is this due to change in leg master regulatory gene during evolution?


What is an example of a change in expression of a single gene leading to ectopic organs?

In flies Dlx specifies leg precursor cells and Ubx represses DLx. Ubx is expressed in abdomen.
In crustaceans Ubx doesn't act as a repressor - they have a anti-repression motif that was lost in insects