0203 Final

ANSWER ALL QUESTIONS (1)

The efficiency of transforming genes into rice via Agrobacterium is found to be variety dependent. It is much easier to transform japonica rice than indica rice. (a) Based on your current knowledge on plant tissue culture, plant regeneration and Agrobacterium-plant interaction, what parameters you will test in order to improve the Agrobacterium-mediated transformation of indica rice? Explain your answer. (6 marks) (b) Will there be variety differences if we use gene gun bombardment instead? is the major disadvantage of the gene gun approach? (2 marks)

(2)

What

A team of scientists has discovered several kinds of well preserved ancient insects inside a cave in an ice mountain. Based on their morphology, they do not belong to any of the recent insect taxa. (a) Will you recommend them to use SSR or ISSR experiment to generate a molecular phylogeny for these ancient insects? Explain your answer. (2 marks) (b) Can you use the same method to study phylogeny of distinctly related organisms? Explain your answer. (2 marks)

(3) Gene therapy and animal cloning are controversial topics in our society. (a)

What are the fundamental differences between somatic gene therapy and germ line gene therapy? (3 mark)

(b)

The success of animal cloning also brought new insight in the regulation of cell cycle. How will this affect somatic gene therapy? (3 marks)

C

G

H

I

A

B

D

E

J

F

L

M

N

O

P

(4) The relationship of individuals in the above pedigree is as follows: Square: male; Circle: female A/B, C/D, E/F are couples D and E are monozygotic twins, sons of A and B G, H, I, and J are sons and daughters of C and D L, M, N, and O are sons and daughters of E and F Only C, F, G, H, I, J, and P are still alive

(5)

(a)

What proportion of genes is in common between J and L? (2 marks)

Explain your answer

(b)

A child of E and F was kidnapped when he was a baby. Many years later, P came and claimed that he is a son of E and F. Since E was died, no DNA sample can be obtained. Based on the information stated above, can you suggest a way to determine of P is really a son of E and F.? (5 marks)

A group of scientists tried to investigate seed development related genes in rice. After constructing a cDNA library from development seeds, they find that most cDNA clones are those encode seed storage proteins (mainly glutelins, prolamins, and albumins). Suggest an effective approach to handle this situation. Explain your experimental strategy in details. (6 marks)

(6)

A group of scientists tried to perform proteomic studies on developing seedlings. However, they found that there too many proteins on the 2-D protein gel so that spots overlapped to each other. Suggest some ways to circumvent this problem. (4 marks)

(7) You have learnt the yeast two-hybrid technique in class. A more sophisticated technique called yeast three-hybrid technique was invented to study RNA-protein interaction. The principle is that if one RNA molecule contains two protein binding sites, it will act as a linker to bring the two proteins to close proximity (analogous to the yeast two hybrid system that requires physical interaction of two proteins). Suppose that you have obtained the following constructs: (i)

A yeast vector expressing a fusion protein shown below: LexA DNA binding domain

The RNA binding MS2 coat protein

(ii) A yeast vector expressing a hybrid RNA shown below: Binding site for MS2 coat protein

Binding site for a RNA binding protein X

(iii) A cDNA library constructed in a yeast vector expressing fusion proteins shown below: Protein portion encodes by cDNAs inserted in the vector

Describe the strategy you will used to clone protein X.

- END -

LexA DNA activation domain

(10 marks)