Writing in Biology

In lab we did an experiment of finding out what bacteria are in the environment around us. We did this by swabbing our environment and then inoculating a plate of TSA (Trypticase soy agar) a non-selective or differential media. For my environmental swabs I chose my water bottle mouth piece and my dogs mouth. I swabbed both with seperate swabs and inoculated two different plates. The results were kind of gross. Both plates were lawns, which means there was so much bacterial growth over the 5 day long incubation that there wasn’t a single isolated colony. It was a little surprising that my water bottle had so much bacteria on it, but now that I think about it it makes a lot of sense. Your mouth has countless different types of bacteria in it so it would make sense that anything you put your mouth on has countless different types of bacteria in it. And my for my dog’s mouth, well he’s a dog. I was expecting that to be super gross. I wish that we had other plates to select or promote certain bacterial growth just to see the diversity of bacteria that is growing everywhere in the world around us. Some girl did a soda gun at work and came back with similar results to my plates. That seems really gross. At least with my bottle it is the bacteria that belongs to me and is always living inside of my mouth. I would prefer not to drink the bacteria of people serving me soda.

There is a new study that show that a sleep-deprived brain is more likely to have excess amounts of two proteins which lead to Alzheimer’s. These proteins are called Tau, which is tied to nerve cell death can tangle and spread throughout the brain when one has Alzheimer’s. There is also mention of another protein A-beta that has a negative impact on sleep. This is important in that treating sleep disorders may be vital to prevent Alzheimer’s. Both of these proteins do not show a direct link to getting Alzheimer’s but indirectly they point to it. They are sure to note that sleep deprivation seems to impact Tau more than A-beta, where Tau is the more dangerous of the two proteins. They may set the stage for later problems and it is important to be aware of this for the future.

The article is about how teenagers use cannabis and how it affects the brain. The use of cannabis increases the amount of gray matter in teenagers, even if it is a joint or two. The study was conducted with 46 kids who had admitted to having exposure to cannabis before the age of 14. There is an increase of gray matter in parts of the brain where cannabinoid receptors are. Most of the gray matter were in the amygdala. The amygdala is the part of the brain that is used to control fear and other emotions. The hippocampus is also involved and the hippocampus focuses on memory. Since the brain is still developing, the brain is supposed to get thinner and not thicker. Since, most people think having a joint or two isn’t a big deal in reality it has an affect on the growing brain.

Evolution and acclimation are often confused with one another. The former is a change over time in a population or a species such that the descendants differ from the ancestors. However, acclimation is change in an individual's physiology. Other differences between the two are that changes brought about by evolution are heritable, while the changes due to acclimation are not passed onto the next generation. One aspect that confuses many students in biology is that the ability to acclimate itself is heritable due to evolution, but the acclimation of an individual itself is not heritable. An example of evolution is observed in polar bears, which have evolved their white fur, matching the color of the snow. Random mutations lead to this white color, and because of the fitness advantage, the genes for white fur were passed on, changing the population. An example of acclimation is the tanning of human skin after long durations in the sunlight. This physiological change came about, but is reversable, and cannot be passed onto the next generation. If a person tans, their child will not be born the skin color of the parent's tan. However, humans have the ability to tan because evolution allowed them to tan. Those who were able to tan were more protected from the sun, giving them a fitness advantage. A fitness advantage is the advantage that comes from an adaptation allowing an organism to more likely reproduce and pass on their genes.

In order to treat both pathways, we are planning to use elements of CRISPR gene editing techniques.  In order to target the HGSOC cells, two hallmarks of the cancer have been identified: CA-125 and MAGE-A10.  One idea we have is to insert mRNA for the BH3 protein into cancerous cells. The cell could then translate this pro-apoptotic protein.  For the cell proliferation pathway, c-Myc is likely amplified in part due to the extremely common loss of function mutations in p53 (tumor suppressor).  If we could inject mRNA coding for p21 into the cells, then the cell would transcribe p21, the CDK inhibitor that promotes apoptosis, that normal p53 acts as a transcription factor for.  We could also use CRISPR to edit the genome itself, possible looking at promoter/enhancer regions for the c-Myc gene, or just cutting the gene out entirely. More research is needed into how to target this therapy, because once that is sorted out, we view this mechanism as a pretty comprehensive solution to many cancers.

In pancreatic adenocarcinoma, the EGFR/KRAS pathway is commonly mutated and is a promising area of focus for targeted treatment. A targeted drug needs to target mutations in the EGFR/KRAS pathway without halting it completely since the complete inactivation of KRAS would prevent cell proliferation in the pancreas. It would be detrimental to completely halt cell growth and division. A microRNA that would target the point mutation in codon 12 of the KRAS oncogene in PanINs could be useful in serving as a targeted treatment. This would bind to only the mutated mRNAs and halt expression by either blocking translation or destroying them.