Non-Coding RNA Flashcards Preview

Developmental Genetics > Non-Coding RNA > Flashcards

Flashcards in Non-Coding RNA Deck (33):
1

What is the basic pathway for miRNA biogenesis?

.

2

miRNAs are processed from perfect stem loops.
True or False?

False, they are processed from imperfect stem loops, created by Pol II.

3

How many mismatches are tolerated in terms of complementarity to target motifs?

3-4 mismatches.

4

What is the function of the PIWI domain?

Cleaves mRNAs.

5

Why can you often not see cleavage products?

- Exoribonuclease degrades it in the cell.

6

Which has higher complementarity with their target motifs, plants or animals?

Plants.

7

Give an example for the complementary binding of miRNAs within animals.
C.elegans.

.

8

What is the result of low complementarity to target motifs?

.

9

miRNA are thought to regulate ____% of genes.

30-50%

10

What is the seed region in animal miRNA sequences?

- Seed sequence (2-7nt).

11

What are the general rules for miRNA target interaction in animals?

• Targets are usually in the 3’UTR
• Can have multiple target sites
• Imperfect base-pairing
• Target sites are conserved in related species
• Better pairing at the 5’ end of the miRNA.

12

How can miRNAs alter the genomic output of a cell?

.

13

What are some examples of miRNAs targetting regulatory genes that control development?

- miRNA172.
- miRNA164.
- miR-Jaw.

14

All miRNAs are conserved.
True or False?

False, many are rapidly evolving, some are deeply conserved.

15

Examples of deeply conserved miRNAs?

- miR166 -> PHABULOSA.
- Let-7 -> lin-41.

16

What are some current estimates of miRNA genes in animals, plants and viruses?

.

17

Define polycistronic.

many mature genes of same mRNA transcript.

18

Can miRNAs be polycistornic? How are they arranged?

.

19

Where are polycistronic clusters located in the genome?

.

20

What are mirtrons? How can they regulate gene expression, in a self-regulatory fashion?

.

21

How can miRNAs provide buffering for genetic programs?

.

22

What is the effect of having no miRNA buffer in the development of plants?

.

23

How can you regulate miRNAs? Example.

- Target mimicry.

24

How can we determine miRNA function animals? Example.

.

25

How can we determine miRNA function in plants? Example

- Small Tandem Target Mimics.

26

How can we target small RNA activity?

.

27

How can we target small RNA activity?

.

28

What can be used to visualize miRNA activity?

.

29

What is an example of miRNA-target interaction leading to tumour genesis?

.

30

miRNAs can regulate oncogenes and tumour suppressors.
True or False?
If true give some examples.

True.

31

How can miRNA regulation be used to treat human diseases?

• Various cancers: loss or up-regulated microRNAs, also can be due to altered miRNA:target interaction.
• Diabetics: microRNA regulate insulin secretion
• Neuronal disease (aging): microRNA changes
• Obesity: microRNA regulate fat metabolism in livers
• Viruses: microRNA have antiviral activity
• Stem cells: microRNA control differentiation and renewal

32

What is the difference between plant and animal miRNA systems?

.

33

What is the difference between miRNAs and siRNAs?

.