jnduggan's blog

CRISPR/Cas9 has been getting attention recently due to research that found it to be a possible new tool used in genome editing. The research surrounding CRISP/ Cas9 has the potential to change the world of controlled genome editing. New studies are observing if the genome editing can be deemed as a successful option for further research on humans.

     The CRISPR/Cas9 mechanism is comprised of two parts. The regulatory sector of the system is an RNA guide which is programmed to create a sequence that matches the desired DNA sequence. The RNA guide is then bound to Cas9, a protein that has the ability to make double stranded DNA breaks. When the RNA regulatory sector binds to the Cas9 protein, they search through the DNA to find the programmed sequence that matches the RNA sequence. When the RNA sequence binds to the DNA's complementary sequence, Cas9 can make a cut. The cut in DNA allows for the DNA to be edited. Mutations can be corrected, new genes can be inserted, or certain genes can be removed from the human genome.

Even after abortions became illegal in the US, women continued to have them. Practitioners did their work behind closed doors or in private homes. Women without financial means often resorted to dangerous or deadly measures.   Although Roe v. Wade made abortion nationally legal in 1973, over 1,074 restrictive laws have been passed by states in efforts to make abortion as inaccessible as possible. More than a quarter of these laws were passed between 2014 and 2015. If history repeats itself, we could see a resurgence of unsafe abortion practices in the United States.

This reading touches different informed consent laws and the intent and impact of implementing such laws. Neoliberalism also increases the state’s power over women’s bodies through increased abortion restrictions and control over medicine.

Informed consent laws vary greatly from state to state, so even though nationally abortion is legal, many boundaries such as the social pressures implicated by informed consent can arise.

Crispr/Cas9 has come into the spotlight due to recent research, where it has been found to be a possible new tool in genome editing. The possibilities are endless in what can be done with controlled genome editing but to begin the journey on deeming it a successful option further research on humans must occur.

     The Crispr/Cas9 mechanism essential is comprised of two parts. The regulatory part of the system is a RNA guide which is programmed to sequence to match a desired DNA sequence. The RNA guide is then bound to Cas9, a protein that has the ability to make double stranded DNA breaks. When the two are together, they essentially search through the DNA looking for the programmed sequence, and once the RNA binds to the DNA, Cas9 can make the cut. The cut in DNA allows for the ability to correct mutation, insert new genes, or remove certain genes from the human genome.

Our RESEARCH DESIGN was modeled after a paper that studied spider web production in terms of web mass and temperature. Fruit flies were dropped into the web with a relatively complex apparatus that was beyond the scope of our project, so our inverted cup and straw apparatus will serve as a practical substitute. The methods we will follow also closely resemble Barghusen’s paper. We will run the experiment over the course of five days because six days gave indicative results in one of the papers we studied (Barghusen et al). In that paper, a temperature gradient was created using Aluminum pans and a hot plate. Our experiment will create a similar temperature gradient using styrofoam boxes and a heat lamp for the warm condition and ice for the cold condition. The Barghusen paper found that web mass was significantly lighter in the colder conditions, so we expect similar results.

Our RESEARCH DESIGN is modeled after a paper that studied spider web production in terms of web mass and temperatures. Fruit flies were dropped into the web with an relatively complex apparatus, beyond the scope of our project, so our inverted cup and straw apparatus will serve as a practical substitute. The methods we will follow also closely resemble Barghusen’s paper. We will run the experiment over the course of five days because six days gave indicative results in one of the papers we studied (Barghusen et al). A temperature gradient was created using Aluminum pans and a hot plate. Our experiment will create a similar gradient using styrofoam boxes and a heat lamp for the warm condition and ice for the cold condition. The Barghusen paper found that web mass was significantly lighter in the colder conditions, so we expect similar results.

Baker’s yeast has two almost identical mating types, MATa and MATɑ, which can sexually reproduce with each other and asexually reproduce themselves.  If the environment they are in is nutrient poor, the yeast cells can exist in a haploid form of MATa or MATɑ. A colony of haploid cells can be maintained by asexual budding.  If the environment they are in is nutrient-rich, the different mating types will become shmoos, a nodule of the original cell that the cells use to join together. Once they become an a/ɑ diploid, they can bud to asexually reproduce two yeast cells, the new cell being exactly identical to the first. If a diploid cell is starved of nitrogen and also on a carbon-poor source, it will sporulate to form four ascospores within an ascus.  Those spores can be released from the ascus membrane and become four haploid yeast cells, two a and two ɑ cells.

Mutations come about by mutagenesis, which is a relatively rare event in nature.   DNA replication is a highly regulated event that rarely lets imperfections slip by. Even when a mutation occurs in DNA, it does not always lead to a change in phenotype. Mutagens such as UV light, as used in this experiment, X-Rays, and chemicals are often used to increase the frequency of mutations for scientific study. In order to successfully study mutations, the cells must live and be able to reproduce through the mutagen exposure and contain a non-lethal mutation.  

We conducted an experiment testing the feeding patterns of Tetrahymena thermophila by combining Tetrahymena culture with India Ink (a food of Tetrahymena).  First, we practiced observing the Tetrahymena under a microscope.  We added Methyl Cellulose to slow their movements, but not kill them.  With new Tetrahymena, we added India ink and after set time intervals, we added in Glutaraldehyde, which kills the cells in time so we may observe the number of vacuoles created after a certain time.  We took 5 samples of cells at 0, 10, 20, 30, and 40 minutes and made a wet mount to record the number of vacuoles created. After looking at 10 cells per sample, we took the average of the numbers we collected for each time interval.  The mean of the rows gave us the average number of vacuoles that were observed after the stated time. We noticed that the longer the cells had with the India Ink, the more vacuoles they made on average. I believe that the data shows that the longer the Tetrahymena are in the solution, the more vacuoles they will form.  We did not see any plateau in the data, but I do think that after a certain point the number of vacuoles would not get any larger. We made a table on Excel to organize all of our data and then made calculations to get the mean and standard deviation. To calculate the mean we used the function “=average (cell range)” and highlighted the data.  To calculate the standard deviation we used the function “=stdev (cell range)” and highlighted the data. A line graph was made from all of this data.

Our experiment studies cellar spider web weight and production in relation to the temperature of the spider's surrounding environment.  This experiment can be used as a microcosm for Earth to show the effects that climate change could have on the survival and location of cellar spiders. Globally, species are expected to shift locations in response to climate change.  When the region an organism resides in becomes too hot or too cold for the organism to thrive, the organism will move towards the poles or equator accordingly to adjust for the change in temperature. If the area becomes too hot to support that species, the members of the species will generally migrate gradually towards the poles in order to stay in an environment that suits their temperature needs.  If the area becomes too cold to support that species, the members of that species will gradually migrate to a warmer area, which is generally towards the equator. Most of the Earth is expected to warm over the next several decades, but there are some areas on Earth that are expected to get colder.

Our experiment studies web production and weight of cellar spiders in relation to the temperature of their surrounding environment, which can be used as a model for the effects that climate change will have on cellar spiders.  Globally, species are expected to shift locations in response to climate change. When the area the organisms are in becomes too hot or cold, they move towards the poles or equator accordingly to adjust for the difference in temperature.  If the area becomes too hot, they will move towards the poles in order to stay in an environment that suits their needs. If the area becomes too cold, they will move to a warmer area, which is sometimes towards the equator, but occasionally not.  Most of the Earth is expected to warm over the next several decades, but there are some areas that are expected to get colder.

If it is observed that web weight or production varies at the temperatures our experiment tests, this could predict how this species of cellar spiders will respond to different temperatures.  Since webs are necessary for a spider’s survival, a deficiency in web weight and production could have detrimental consequences. The cellar spiders may be expected to shift their location accordingly.  If the species is not able to shift locations quickly enough, the species may be at risk for extinction.

On the Duty of Civil Disobedience by Henry David Thoreau explores a civilian’s duty to use their conscience, not pure legislation, to lead their actions.  Thoreau argues that the democracy of his time only makes legislation that grants the wishes of the majority by allowing them to decide what is right and what is wrong.  “Must the citizen ever for a moment, or in the least degree, resign his conscience to the legislator? Why has every man a conscience then?”. Thoreau then encourages men whose conscience finds certain laws unjust, to voice their disagreement through a number of ways.

Firstly, Thoreau warns men that they may be “treated as enemies” by the state for resisting the unjust laws at all.  He explains that the men deemed “good citizens” are the people who disregard their morals and act only in ways that serve the state, such as soldiers.  The Mexican- American war is a pressing issue during Thoreau’s time, causing him to point to soldiers as main proponents of unjust actions for the state. Thoreau compares these men to the worth of “wood and earth and stones” along with only commanding the same respect as “men of straw or a lump of dirt”.  Thoreau wants to prepare the men that will act justly for the resistance they will face on their journey. Although it may be more convenient to act with the majority, Thoreau believes that he cannot act this way “without disgrace...associated with it”. In this way, some people may be prone to follow the government instead of standing up for their rights.