case unit 4 - disease models Flashcards Preview

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Flashcards in case unit 4 - disease models Deck (18):
1

why are models of human disease created



to mimic aspects of human disease

to develop and tailor individual therapies and find out fundamental information

2

why are mice good models

mammals
small
fast-breeding

3

how can you make mice diabetic

chemical destruction of insulin-producing B-cells to produce hyperglycaemia

4

why are knock-out mice used

to determine physiological function of a gene

5

why are knock-in mice used

to introduce specific mutations

6

describe the process of creatig a mouse model

- design modified embryonic stem cells
- inject into fertilised oocytes in blastocyst stage
- transfer into pseudopregnant females
- breed chimeric offsrping with wild-type mice
- screen for germline transmission

7

benefits of CRISPR editing

quick
cheap
could be a cure for hereditary diseases
easy to make knock-in/out mice models

8

why does CRIPSR have a good success rate for knock in/out mice models

you inject specific RNAs into one-celled oocytes then you transfer to pseudopregnant females

9

what are the limitations of disease models

anatomical and genetic differences to humans
have to extrapolate the results
variations induced by techniques
models often dont live long enough to see disease progression

10

what is CRISPR-Cas9

genome editing technology

11

steps involved in CRISPR

- identify unique 20bp region
- clone 20bp sequence
- guide sequence added that hybridises complementarily to target sequence
- Cas9 recruited which binds and cleaves target sequence

12

what is trio-analysis used for

to see if there is a specific genetic mutation causing the rare disease

13

what happens in trio-analysis

parents genomes are deep sequenced to see if there is a specific mutation causing the disease in the child

14

what is a screen used to identify

whether a gene is involved in a process

15

steps inolved in a screen

identify model organism
identify process of interest
random mutagenesis (break/mutate individual genes)
check if the process still works

16

assumption for carrying out a screen

you assume that the process in the model works the same as in humasn

17

advantages of a screen

quick
cheap
simple genetics
ethics and bias free

18

how do you work out which proteins are involved using a screen

use comparison of gene expression