lecture 17 - recombinant dna tech 4

Question 1

what are the two key properties of stem cells

Answer 1

1. ability to self-renew (can go through numerous cycles of cell division while maintaining undifferentiated state)
2. differential potential to differentiate into specialized cell types

Question 2

what are totipotent stem cells? give example

Answer 2

cells can differentiate into embryonic and extra-embryonic cell types
ex. zygote

Question 3

what are pluripotent stem cells? give example

Answer 3

descendants of totipotent cells and can differentiate into cells derived from any of the three germ layers

ex: embyonic stem cell

Question 4

what are multipotent stem cells? give example

Answer 4

can produce only cells of a closely related family of cells
ex. hematopoietic stem cells differentiate into RBC, WBC, platelets, etc

Question 5

what are unipotent stem cells? give example

Answer 5

can produce only one cell type, but have the property of self-renewal which distinguishes them from non-stem cells
e.g. muscle stem cells.

Question 6

what is somatic cell nuclear transplataion SCNT

Answer 6

when you remove the nulceus of an egg and replace it with nucleus of parent cell

Question 7

what process is used for animal cloning

Answer 7

SCNT

Question 8

what are issues associated with animal cloning

Answer 8

• only small percentage of cloned embyos have developed normally to birth and many cloned animals echibit defects
• many epigentic changes must be reversed in donor animal nucleus in order for genes to be expressed/repressed appropriately for early stages of dev

Question 9

what are stem cells isolated from early embroys at blastocyst stage called and what can they do

Answer 9

embryonic stem (ES) cells; these are able to differentiate into all cell types of the three germ layers

Question 10

how are transgenic animals made

Answer 10

introducing genes from one species into genome of another

Question 11

what are the methods for introducing a transgene

Answer 11

• retrovirus
• miroinjection into eggs/fertizilied eggs
• embryonic stem cells

Question 12

how do you design a transgene

Answer 12

1. select for integration
2. choosing promoter for expression

Question 13

what is selection for integration for transgenes based on

Answer 13

antibiotic resistance genes but these can be later excised to prevent antibiotic resistance in animals

Question 14

what is the cre-lox system

Answer 14

site-specific recombination system which can modify struct, control gene expression and delete genes

Question 15

what are cre and loxP roles in cre-lox system

Answer 15

cre: recombinase
loxP: recognition site for recombinase

Question 16

what was the first transgenic animal? when was it? what were the changes? who did it

Answer 16

expressed rat growth hormone gene in mice liver in 1982 by richard palmer and ralph brinster

Question 17

what was the first transgenic sheep? when was it? what were the changes? how was it done?

Answer 17

tracy was injected with human alpha-1-antitrypsin to treat emphysema/cystic fibrosis. done by microinjecting a zygote in 1990

Question 18

who was the first closed transgenic animals

Answer 18

molly and dolly (1997)

Question 19

what are CAR-T cells and what are they used for

Answer 19

inject CAR (chimeric antigen receptor) into T cells using retroviral vector. used to treat blood cancers for now

Question 20

what are Induced Pluripotent Stem Cells and what do they do

Answer 20

transform skin cells into ES cells using viruses to introduce stem cell master regulatory genes. can be used to treat some diseases and replace nonfunctional tissues

Question 21

what are the master regulatory genes necessary for iPSCs

Answer 21

OCT4, SOX2, KLF4, c-Myc