STEM I

About the Course: STEM and Scientific Technical Writing is taught by Dr. Crowthers here at MAMS! For the first phase of this course, we all complete an independent research project, which we present in February at the school fair. From there, select individuals are chosen to go onto WRSEF, MSEF, and even ISEF. Below you can find information regarding my project this year.

Project Overview: In my project, I investigate how blue light affects circadian rhythms in humans, using Drosophila as a model. In modern day, we use technology for long periods of time, exposing us to an excess of blue light. To simulate this, I raised one group of flies under white light and blue light, and later conducted behavioral assays on each of them to measure how badly the rhythmicity of their clocks were damaged.

Click here to read my project proposal.

Research Question:

How does excess blue light exposure affect behavioral patterns in D. melanogaster?

Hypothesis:

Drosophila will exhibit abnormal behavior, as inhibited cryptochromes will disrupt their circadian rhythms.



Circadian rhythms are endogenous clocks that regulate biological processes in all living things

> Irregular sleep is a common issue caused by disrupted circadian rhythms

> Blue-light sensitive genes (CRY1 & CRY2) control clock steadiness/regularity

> Excess blue light causes genes to shut off

> D. melanogaster contains these genes, as well as humans

> Genes can be inhibited by other time-dependent genes OR overexpression







Drosophila will be split into two groups: one that is kept under a 465nm blue light, and one that is under white light. They will have light for 12 hours and darkness for 12 hours to make for one 24-hr day, simulating the natural period for their circadian rhythm. The lights will be automated by a programmed Arduino that is connected to strip lights, so that there is no human error when it comes to giving light cues. After one week, three behavioral assays will be conducted: negative geotaxis, chemotaxis, and phototaxis. Results from both white and blue light groups will be compared and analyzed to determine the effects that the different lights posed on the flies.

Graphs that were made after each of the assays:

Negative geotaxis is the ability of a fly to respond to changed in gravity

Phototaxis tracks the flies' attraction to light

Chemotaxis tests their olfactory senses to distinguish between food (water and 5% sucrose)

Analysis: Through each day of consecutive testing, there is one major thing to note: most groups of drosophila demonstrated declining behavior as time went on. What's curious is that this applied to both white and blue light groups; however, blue light continuously remained at a lower value than the white light group. This might also hint at harmful effects from white light as well, as

Discussion: Seeing as blue light was able to significantly degrade behavior in Drosophila, this information can be linked back to humans to conclude that blue light is indeed harmful to humans. Judging by syptoms shown in flies, this might be linked to restlessness, brain fog, and loss of appetite, just to name a few.