HSS 3109- FINAL UPDATED ACTUAL QUESTIONS AND CORRECT ANSWERS

HSS 3109- FINAL UPDATED ACTUAL QUESTIONS AND
CORRECT ANSWERS

Question:
1. Why do system models focus on mice?
Answer:
easy to modify genome of their embryonic stem cells, 88% homology of coding DNA with humans,
produce large litters, short gestation time, small

Question:
2. T/F non-coding mice DNA is not homologous with human genes, but coding DNA is
Answer:
true

Question:
3. How is transgenesis used in health bioscience research?
Answer:
label proteins and cellular structures, the study of a protein

Question:
4. What is transgenesis?
Answer:
adding foreign genetic material into an organism's genome to produce a new function

Question:
5. What is knockout?
Answer:
blocking of a specific gene to disrupt an existing function

Question:
6. T/F knockout equals loss of function and transgenesis equals gain of function
Answer:
true

Question:
7. What is the importance of genetic knockout?
Answer:
to understand the physiological role of a specific gene

Question:
8. What are the 3 approaches to introduce a transgene or create a knockout mouse?
Answer:
retroviral approach, DNA injection, embryonic stem cell approach

,Question:
9. How does the retroviral approach work?
Answer:
starts with a female mouse, a transgene is added to a retrovirus when the mouse embryo is at the 8 cell
stage

Question:
10. How does the DNA injection approach work?
Answer:
starts with a female mouse, DNA injected directly into male pronucleus of a fertilized oocyte

Question:
11. How does the embryonic stem cell approach work?
Answer:
DNA with targeted transgene is introduced into embryonic stem cells, targeted embryonic stem cells are
selected and expanded, targeted embryonic stem cells are injected into early mouse embryo

Question:
12. How do you introduce a transgene in embryonic stem cells?
Answer:
electroporate vector in embryonic stem cells, establish homologous recombinant embryonic stem cells by
1st screening, PCR analysis and southern blotting

Question:
13. How do you generate chimeric embryos?
Answer:
select embryonic stem cells that have incorporated the transgene, microinject transgenic embryonic stem
cells into host embryo, integrate transgenic embryonic stem cells into embryo

Question:
14. What is a genetic chimera?
Answer:
a single organism composed of cells with distinct genotypes

Question:
15. What are the steps involved to generate chimeric mice by microinjection of chimeric embryos?
Answer:
implant chimeric embryo into oviduct of a pseudo-pregnant recipient female, obtain chimeric mice 19-21
days later

Question:
16. What is the contribution of transgenic embryonic stem cells estimated by?
Answer:
coat colour

Question:
17. What is the workflow to generate transgenic mice with the ES cell method

, Answer:
Introduce transgene in embryonic stem cells, generate chimeric embryos, generate chimeric mice

Question:
18. What are chimeric embryos?
Answer:
Embryos composed of cells with distinct genotypes

Question:
19. What is the F1 generation?
Answer:
The first generation of offspring from the chimeric mice

Question:
20. What is the F2 generation?
Answer:
The second generation of offspring, with ¼ of the progeny having 2 transgenic alleles

Question:
21. What are the strategies to create a Knockout mouse model?
Answer:
Homologous recombination, Introduction of Neo cassette, Two-step selection

Question:
22. What is homologous recombination?
Answer:
A method to disrupt the expression of a gene by introducing a Neo cassette into any important coding
region

Question:
23. What is the consequence of improper placement of the Neo cassette?
Answer:
incomplete knockout

Question:
24. What can generate RNA species that have some coding sequences from the targeted allele?
Answer:
differential splicing or read-through transcription of the drug resistance gebe

Question:
25. What is the critical region?
Answer:
An important coding region of a gene that is essential for its function

Question:
26. What are alternative or cryptic promoters