Cell Module BIOL212 Group #: BIOL212 Cell Module Lab Report ( /35) Group members names: By placing a team member's name on this document, your group is attesting that this person was present and contributed to the group effort for the duration of the session, or until the assignment was completed. Part I: Background and Theory (/16) 1. What is the main hypothesis we are testing in the Cell Lab? (1 mark) Click here to enter text 2. What are the three stages of CRISPR? Briefly outline what is occurring at each step. (3 mark) Click here to enter text 3. Do you think bacterial CRISPR regions will continue to increase in size (and viral diversity) indefinitely? Why or why not? (2 marks) Click here to enter text 4. What are two possible reasons bacteria would have multiple CRISPR arrays in their genome (CR1 and CR3)? (2 marks) Click here to enter text
BIOL212 Cell Module fi. Use the following figure from one of the first CRISPR publications (Barrangou et al., 2flfl7), to answer the following questions. You may wish to consult the original article for reference. (8 marks) S9 $11 S3 S12 S5* S1 $4* S13 Ā¢858 -2-3 4 5 6 7 - 8 9 10 |123451647 19 20 21 22 37 39 40 4414 46 S14 S7 packaging! capsid morphogenesis S9 $11 S10 tail morphogenesis S3 S12 S5 S2* host lysis S8* S6 replication Ā” transcription regulation S1* $4| S13 $2972 -1-2 3-4 5 6 -78 9 123415 07 18 19 20 21 35 37 38 S14 S7 S10 S2* S8 S6 1 kb Fig. 2. S. thermophilus phage genome maps with the position of sequences similar to the acquired CRISPR1 spacers of the phage-resistant mutants. Spacers shown above and below the genome maps indicate that the spacer matches a sequence on the (+) and on the (-) strand, respectively. An asterisk indicates the existence of a SNP between the spacer sequence and that of the phage genome (fig. S1). The genome sequences of phage 2972 (accession number AY699705) and phage 858 are 93% identical. A) Looking at the distribution of acquired viral genome CRISPR sequences in this S. thermophilus strain, are there specific functional regions which seems to have an over/under enrichment of CRISPR sequences? Explain your reasoning? (2 marks) Click here to enter text B) Would all of the CRISPR cassettes (S1-S14) shown in the figure above provide equivalent resistance to phage 2972 and phage 8fi8? Use specific examples to explain your thinking. (2 marks) Click here to enter text C) Do you think a bacterial cell would acquire and maintain multiple CRISPR sequences from a single phage? why or why not? (2 marks) Click here to enter text
BIOL212 Cell Module D) Is there any preference for + or - DNA strand in the acquired CRISPR sequences? Why might this be? (2 marks) Click here to enter text Part II: Results and Discussion (/19) 6. What was the frequency of BIM generation in your experiment?