Monthly Archives: November 2016

Intermediate Stage of Project: Project Outline

Here is the link to my project outline: project-outline

One lesson that I learned while working on my project outline was that dividing the work over the span of many days was an effective approach to completing a large assignment. My strategy to complete the project outline involved setting intermediate deadlines for each section so that when the deadline for the full outline approached, I was not overwhelmed with a lot of work. This strategy worked well for me and I plan to use this strategy again for future projects in other courses.

Top Three Assignments: Group 3 Honeybee Assignment

The assignment for the honeybee unit was one of my favourite assignments because it provided the opportunity for different groups in the class to propose different mechanisms in a process of interest, and eventually combining all of the information into a single model. I enjoyed both sharing my group’s paper and learning about the papers assigned to other groups. I found it fascinating that even though each group presented a different mechanism that influenced caste switching, none of the ideas contradicted each other, but instead, complimented each other when combined into a single, consistent model.

Through this experience, I learned that there may not be a single and simple answer to a research question. As demonstrated in the honeybee unit, there can be multiple mechanisms involved in a process, which highlights the importance of having an open mind to different points of view. Overall, this assignment showed me that collaborating with others who have different ways of thinking is an effective way to achieve a fuller picture.

Here are the links to the questions assigned to my group and my answers, respectively:

group3_paper_and_questions

answers-to-group-3-questions

Unprompted post: Haiku about genetics

In the form of a haiku, I describe how I view the study of genetics:

Genetic puzzle.

Small pieces of big picture

Help find the answers.

To elaborate, I consider genetics to be like a puzzle because it is a mystery that has yet to be fully solved. In my opinion, there is much that we can learn from studying genetics because it is connected to all life sciences. I believe that the more that we learn about genetics, the more that we can understand the inner workings of all living things, including ourselves.

Unprompted post: Midterm #2 Reflection

Midterm #2 was a learning experience for me. Beyond getting to know an academic paper in great depth, one of the biggest lessons that midterm #2 taught me was that I should be more skeptical of what journal articles claim. This was especially clear to me when we did the group component of midterm #2. Through collaborative discussion, my group came to the consensus that the paper for midterm #2 presented data that showed a correlation between peculiarities of the Xi in female lymphocytes and predisposition of expression of normally silenced genes, but the findings presented were not sufficient to show a cause and effect relationship. In order to confidently establish a cause and effect relationship, the authors needed to perform a manipulative experiment to induce “the cause” (i.e. changing Xist RNA cloud localization patterns) to see if we can observe the expected effect (i.e. changes in gene expression). However, instead of performing a manipulative experiment, the authors performed an observational study, from which they could only observe correlations.

In the past, whenever I read journal articles, I always accepted the claims that researchers made. But from now on, I will be more skeptical of claims and think critically before I accept them.

Response to prompt: Public opinion of genetically modified foods

Prompt:

Genetically engineered foods are greatly criticized, and often feared, by many people. Initially people feared that exogenous DNA from the food item could then transfer to the consumer’s cells and cause harmful effects. More recently (and with the advent of siRNA technologies) there is a worry that ‘transgenic RNA’ from the food could get into the consumer’s cells and cause misregulation of the consumer’s genes. What is your view on this, and how would you present it to someone who has no biology background?

As an informed genetics student, I do not share the fear that some people have against genetically modified foods. In fact, I support genetic modification of foods because there are several benefits such as increased yield and nutrition, and decreased need for the use of pesticides.

However, I can imagine that many people who worry about the consequences of genetically modifying food may not have a background in the study of genetics, and are thus uninformed about what genetically modified foods can and cannot do. Therefore, by educating the public about genetics, we will be able to reduce misconceptions that may contribute to the public’s concern about genetically modified foods.

One way to better inform the public about genetics is to incorporate more genetics at the high school level in general science courses. Personally, I did not learn very much about genetics until I started studying in university and enrolled in genetics courses. Therefore, I would expect most people to have a limited knowledge of genetics unless they decided to pursue the study of genetics at the post-secondary level. If more genetics were taught at an earlier age, when general science courses are mandatory, I believe that the general public would be able to make more informed opinions regarding genetically modified foods.

Unprompted post: If I could choose one application for induced pluripotent stem cells

If I could choose one application for induced pluripotent stem cells (iPSCs), I would use them to regenerate organs to resolve organ failure. Two major advantages of using iPSCs to treat organ failure are that no organ donors are required and that graft versus host disease is avoided.

Since iPSCs are derived from a patient’s own cells, organ donors would not be needed. As waiting lists for organ transplants can be quite substantial, using iPSCs to regenerate organs can allow for a more immediate solution to relieve the struggle for a large number of patients.

In addition, by using a patient’s own cells to make iPSCs for organ regeneration, graft versus host disease is prevented because the cells involved are genetically identical to the cells of the patient. Therefore, we can avoid problems associated with receiving organs that the body considers to be foreign.

However, the major benefit of iPSCs being genetically identical to the cells of the patient can also be considered a problem that could inhibit iPSCs from being an effective solution to replacing organs. For example, some instances of organ failure may occur as a result of genetic predispositions. If an organ is replaced with cells that contain the same genetic defects, it is possible that the new organ may eventually fail as well.

Taking into consideration both the benefits and problems that I have discussed, I am in favour of supporting research that would one day allow the use of iPSCs for organ regeneration. Although iPSCs may not the answer to solving all organ failures, especially those that are caused by genetic defects, iPSCs can greatly reduce the dependence on organ donors and prevent complications such as graft versus host disease.

Learning Journal #4

One technique that I learned more about in BIOL 463 is CRISPR/Cas9, which stands for clustered regularly interspaced short palindromic repeats and CRISPR associated protein 9. Based on a mechanism of adaptive immunity in prokaryotes against viruses, CRISPR/Cas9 is used by researchers to edit genomes in cells. Essentially, the CRISPR/Cas9 system aims to induce site-specific double-stranded breaks in the genome of cells to allow homology directed repair after adding a DNA template consisting of the modified sequence which we wish to incorporate.

If someone were to learn how CRISPR/Cas9 works, I think the most difficult aspect of this technique to understand is that the single guide RNA (sgRNA) used to target the DNA sequence of interest must consist of both CRISPR RNA (crRNA) and trans-activating CRISPR RNA (tracrRNA). Although the crRNA component of the sgRNA is what actually binds to target DNA by complimentary base pairing, the crRNA component is not sufficient to allow cleavage to occur by Cas9. As CRISPR/Cas9 is famous for its ability to allow site-specific modifications, students who first learn about CRISPR/Cas9 may become too focussed on the aspects that allow specific targeting, such as crRNA, and may overlook another aspect that is not involved in targeting DNA, but is necessary for the CRISPR/Cas9 system to work, such as tracrRNA, especially when the two components are part of a single RNA construct.

If I were to test a person’s understanding of how CRISPR/Cas9 works, I would ask: Why is a DNA template necessary to allow genome editing to occur through CRISPR/Cas9? In an answer, I would expect the person to acknowledge that without a DNA template, double-stranded breaks in the DNA will lead to non-homologous end joining, which results in the incorporation of random bases, and thus random mutations. Purposeful genome editing involves specific modification of sequences, rather than random mutagenesis. Therefore, a DNA template is necessary to allow specific modification of target DNA sequences.

Intermediate Stage of Project: Updated Research Question

In a previous blog post (https://blogs.ubc.ca/lai463/2016/09/24/draft-research-question), I had shared a draft version of a research question that I was considering for the final project, which was the following:

“Are there genes that are expressed by the developing embryo that induce tolerance against the mother’s immune system?”

However, I later learned that my question had already been investigated. Therefore, I decided to create a new and original research question:

“Is chronic prenatal alcohol exposure sufficient to decrease production of IL-1β, IL-6, and TNF-α by alveolar macrophages in response to infection by Streptococcus pneumoniae during adulthood in mouse models?”

There are a few reasons why I chose this question:

Firstly, I wanted to propose an experiment that could increase our knowledge of the immune system. I am an Integrated Sciences student with immunology as one of my integrations, so I am interested in learning more about the immune system.

Secondly, as the course title of BIOL 463 is “Gene Regulation in Development”, I wanted my research question to relate to development by investigating how a particular treatment during an early stage of life can affect processes in the body later in life.

Thirdly, I was inspired to study the effect of alcohol exposure because I have experience as a research assistant performing alcohol experiments to investigate the effect of acute alcohol exposure on learning (link to a previous post where I interpreted data that I collected: https://blogs.ubc.ca/lai463/2016/11/02/unprompted-post-data-interpretation-outside-the-classroom/).

Finally, I designed my question to be very specific to ensure that my question has not yet been investigated. This is important to me because I want my project to allow the potential discovery of new information that no one has ever known. In my opinion, by investigating an original question, the outcomes of the investigations are more meaningful.

With my new and original research question, I look forward to completing the rest of my final project.

Techniques Presentation: CRISPR/Cas9

Link to the write-up and presentation CRISPR/Cas9 Write-up and Presentation.

Looking back, I am glad that I had the opportunity to learn more about CRISPR through the Techniques Café, especially because in Learning Journal #1, I had expressed interest in learning about CRISPR in BIOL 463. After the Techniques Café, I received more than what I had hoped for in terms of learning about CRISPR. Instead of just learning about CRISPR, I taught others about CRISPR, which required me to have a solid understanding of it myself in order to effectively talk about the technique. Taking this into consideration, I believe that I learned a lot more from presenting CRISPR than I would have if I had simply listened to another group teach me about CRISPR. Overall, it was a satisfying experience to both learn about something that I wanted to learn about and learn it really well.

If I were to test a person’s understanding of how CRISPR/Cas9 works, I would ask: Why is a DNA template necessary to allow genome editing to occur through CRISPR/Cas9? In an answer, I would expect the person to acknowledge that without a DNA template, double-stranded breaks in the DNA will lead to non-homologous end joining, which results in the incorporation of random bases, and thus random mutations. Purposeful genome editing involves specific modification of sequences, rather than random mutagenesis. Therefore, a DNA template is necessary to allow specific modification of target DNA sequences.

Unprompted post: Data interpretation outside the classroom

Throughout the term, BIOL 463 has provided students with many opportunities to practice data interpretation. Big questions that have been frequently asked include, “What does the data show?” and “What can you conclude from the data?”

Recently, I had the opportunity to interpret data that I had collected myself at lab where I am a volunteer. This was exciting for me because it was a chance to apply the data interpretation skills that I learned in BIOL 463 outside of the classroom. Here is a graph that illustrates my data:

1-1

Background information:

  • At the lab where I volunteer, C. elegans is used as a model organism to study the neurobiology of learning.
  • Habituation is the process in which a diminishing physiological or emotional response occurs in response to a frequently repeated stimulus, which is a form of learning.
  • The particular project that I am involved in assisting investigates the effect of acute ethanol exposure on habituation in different strains of  C. elegans with different mutations in genes suspected to be involved in learning.
  • N2 = Wild type strain
  • RB665 = Mutant strain with a deletion in the gene that encodes a D1-like dopamine receptor
  • 0 mM indicates that no ethanol was present in the agar media (no alcohol treatment)
  • 400 mM indicates that 400 mM of ethanol was present in the agar media (alcohol treatment)
  • The x-axis indicates the number of stimuli received in the form of taps to the plates containing the worms.
  • The y-axis indicates the probability of response to each tap, as measured by a computer system.

Before I provide my interpretation of the data, I have some questions for you:

What does the data show? What can you conclude from the data?

I encourage you to try answering these questions to see if your interpretation is different from mine.

Here is my interpretation of the data:

When comparing untreated RB665 to untreated N2, there is an increased decline in the probability of response to repeated stimuli. There is increased habituation in untreated RB665 compared to untreated N2, but similar habituation in alcohol-treated RB665 compared to alcohol-treated N2. Furthermore, although the probability of response to initial stimuli is lower in alcohol-treated N2 and RB665, the degree of habituation is observed to be the same when comparing untreated and treated worms within the same strain. Therefore, I would conclude that acute alcohol exposure is not sufficient to alter habituation, and normal-functioning D1-like dopamine receptor is necessary for normal habituation in the absence of alcohol treatment, but D1-like dopamine receptor is not necessary for normal habituation that would be observed in the presence of alcohol treatment.

It took me quite a while to formulate this interpretation, and when I sent it to my lab supervisor, I was not entirely sure if my interpretations were valid. But, to my surprise, my lab supervisor approved of my interpretation of the data.

What do you think?