Epigenetics Flashcards Preview

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Flashcards in Epigenetics Deck (10):
1

A change in phenotype that does not result from a change in the sequence of the gene.
-caused by a mechanism other than mutation
-Change is heritable

Epigenetics

2

Signal received---> chromatin changed without changing DNA sequence
*Not all genes are expressed at any given time

Epigenators

3

The interplay between DNA methylation and histone acetylation, and RNAi to completely repress expression of genes
-CpG island is unmethylated (allows for txn machinery to bind) ----->CpG island methylated (physically blocks txn machinery from binding)

Gene silencing

4

Is reversible, but more permanent than not
-Sometimes methylation recruits histone deacytlases to modify histone tails

Gene Silencing

5

-Done in response to signals not spontaneous
-Big insulator proteins stop processes
-Packing pattern is heritable

Histone Tail Modification

6

-Transfer acetyl groups to histone tails, masking their (+) charges
-Relaxes histone and allows txn machinery to get in

Histone acetyl transferases (HATS)

7

-Recruited by DNA methylation
-Reverses histone acetyl transferase activity

Histone Deactylases

8

Regulatory RNAs control target mRNA degradation
Done by:
microRNA (miRNA)
short-interfering RNA (siRNA)
-Used:
*during development
*immune system of cell against viruses

RNA interference (RNAi)

9

Protein that picks up shRNA because it recognizes it

RISC (RNA interference silencing complex)

10

(In nucleus) miRNA--->transcribed--->miRNA transcript--->processed---(outside of nucleus)-->short hairpin RNA (shRNA)--->processed--->RISC picks up shRNA--->binds to target mRNA----->RISC cuts mRNA---->mRNA degraded by exonuclease activity

Process of RNA interference