March 2024

Smoking plants

Lincoln-West Updates

Students are coming back from spring break renewed and ready to pick back up their experiments! Currently, we have 18 projects underway in six classrooms. Here few highlights: 

Students investigating the neurological impact of cannabinoid exposure have dosed the social hermit crab species Coenobita clypeatus with CBD oil and built custom made behavioral chambers to read out effects on anxiety and predator-evasive behavior. To accomplish this, students rigged a computer and webcam up to a sheltered box and used putty to adhere crab shells to a mat within the box. After several rounds of acclimatization (in which students observed the crabs coming out of their shells), students used the computer screen to switch from a black screen to a predator (hawk) while recording hermit crab responses. This allowed them to see if CBD has a calming or anxiety inducing effect. These students have begun dissecting hermit crab tissue to attempt to use polymerase chain reaction (PCR) to isolate the region of DNA associated with the response to  CBD before sequencing. The hermit crab genome has not been sequenced - will be the first attempt at identifying this region of DNA in the animals and will allow students to understand more about how CBD potentially works at the molecular level in these animals.

Students interested in the impacts of social isolation on our health have used earthworms - housing worms in different conditions with other worms or by themselves. These students performed multiple behavioral assays to determine whether the worms exhibit depressive-like behaviors and have even used an electrophysiology spiker box to measure neural activity in the worms! Students collected the worms for processing and will be dissecting ganglia when they return from break to perform Western blots to measure serotonin receptor protein levels.

We have a group of students interested in stem cells. This group is using the regenerative flatworm Planaria and the regenerative segmented blackworm to see if different signaling pathways and proteins regulate regeneration. After microscopically cutting Planaria and blackworms, students are treating the springwater from a group of the worms with FGF8. They have already found that FGF8 induces faster regeneration but normal looking development. Students are expanding this to include the signaling teratogen retinoic acid after break. We have reason to suspect this will lead to some very interesting results!

Our Drosophilist groups are going strong. One group interested in how age impacts your susceptibility to diseases have been using UV light to induce random mutagenesis in either larva/pupa alone or in adult flies before collecting tissue to measure DNA damage through levels of yH2AX by Western blot and by assessing DNA shearing using electrophoresis. Another group has optimized levels of sleep deprivation to understand more about why we need sleep. Using mechanical and light stimuli, flies are deprived of sleep for 3 weeks before looking at fly behavior and dissection of brain tissue for analysis of protein levels. These are just two of many fruit fly experiments underway, amongst plant (see above: students smoking plants), cockroaches, earthworms, C. elegans, and more!

Working with bacteria

Garrett Morgan Updates 

Projects at Garrett Morgan began in earnest on March 6th and these students have wasted no time collecting data! We have 8 projects underway in two classes. 

One group of students wanted to know if and why seeds would grow differently if they had been ingested by an organism. To do this, they researched what type of seeds earthworms would eat and identified nitrogen rich seeds as best. They first attempted to co-house individual earthworms with a set number of seeds in a petri dish overnight before counting the seeds to determine whether the earthworms ingested any. The plan was to then move the earthworms to a new dish for defecation or dissection, however as science always takes unprecedented twists and turns, the earthworms escaped overnight and were found deceased across the room the next day! Students modified their approach and repeated before break. These students will plant the defecated seeds, undigested seeds, and seeds dissected directly from the digestive tract to evaluate growth rates while also measuring plant hormone response through levels of RGA, a component of the gibberellin pathway.

Another group in the next class is interested in mechanisms of antibiotic resistance in bacteria and bacterial evolution. They have looked at how they can use pathway modulators to block expression of RFP in bacteria to understand more about signaling cascades and the central dogma, and more recently performed a Kirby-Bauer antibiotic disk diffusion test to measure the growth of E. coli in response to a range of antibiotics. Students saw the famous Harvard time-lapse of bacterial evolution on a mega plate with different concentrations of antibiotic and are looking forward to studying this process more in their own hands.

Finally, another group is interested in gene-environment interactions in the development of Alzheimer's disease. They have maintained stocks of genetic strains of fruit flies with the UAS/GAL4 system. The driver GAL4 is expressed under control of ELAV to isolate phenotypes to the nervous system; by crossing these flies to UAS- human tau control and mutant strains, they have made Alzheimer's fruit flies. Students are modifying the food of fruit flies, with a specific interest in cholesterol, to see if mutant flies develop symptoms of Alzheimer's faster than those in normal feed conditions. This information will tell us more about how diet can promote early onset Alzheimer's disease.