Week 3: Growth

This week, I was able to reproduce my previous results using different isolates. I found that one terminal oxidase mutant consistently shows higher-than-normal β-galactosidase activity, which means that the ctaA promoter attached to the lacZ gene is being activated by something. I also found that the lab’s two isolates of ∆qox mutants have different β-galactosidase activities.

Now I can plan step 2 in my project. I’m interested in two of the terminal oxidase mutants (including one isolate of ∆qox) because their higher-than-normal β-galactosidase activity implies that ResD may be unusually active in aerobic conditions. We believe that ResD is the transcriptional activator that binds to the ctaA promoter and activates the transcription of the lacZ gene in this situation. However, we need to confirm this hunch! To do so, I plan to perform Western blots to compare the relative amounts of ResD and ResE protein in wildtypes and mutants. Since ResD promotes its own transcription by binding to the resA promoter upstream from its own gene, bacteria with unusually active ResD should also have unusually high levels of ResD protein in them.

There was one disappointing setback this week. I had planned to check the reproducibility of my work using another construct, resA-lacZ strains. A long time ago, Michiko (my PI) had done this experiment using that construct, and her old results were not the same as my results. It was worth seeing if what I saw in ctaA-lacZ strains also occurred in that construct. However, we could not find the resA-lacZ wildtype anywhere in the lab. I cannot do the experiment until Michiko remakes the resA-lacZ wildtype strain.

On the professional development side of things, I learned a lot this week. On Monday, I learned about citation software and how to use it. I had always found the software confusing, so I was glad we had a workshop on it! I downloaded Zotero, and I think it will be really useful for my future writing. On Tuesday, we had a workshop on applying for funding in graduate school. I did not know anything about this topic so it was very eye-opening. On Friday, I met with a graduate student to discuss the process of applying for graduate school. I also attended a seminar where graduate students shared their perspectives and experiences.

Out of all of my events, I think the one-on-one talk with the graduate student helped the most. We discussed the entire process of applying: what initial steps to take (visits to the department, emailing PIs, etc.), how to write a personal statement, and how to interview. She was honest, but also nice and incredibly helpful and encouraging. I plan to put her advice to good use in the future.