Second Week

Early in the week things in my lab slowed down a bit. On Tuesday, most of the people who work in my lab left for Virginia to collect more fish so I had a shorter day in lab. Wednesday though, work picked up again. After doing the usual work in the lab, dosing eggs with different PAHs and looking at eggs that had been dosed a few days before, we ended the day by dissecting the fish that had brought in Tuesday night. This had to be done almost immediately after the fish were brought in so they wouldn't be given a chance to flush out the chemicals in their system that we were testing for. Five of us in the lab set up an assembly line to disect the fish. I was at the very beginning. After taking them out of their tank I put the fish in ice cold water. Usually when putting the fish to sleep they use an anesthetic but this time we couldn't as it might interfere with the chemicals already present in their system. Since fish are cold-blooded, the cold water slowed them down so they wouldn't move, but were still alive so we could take blood (which needs the heart to be pumping). My other job was doing the blood smears after Cole had drawn their blood.

We disecting fish on Wednesday and Thursday morning as well. Thursday I got to see what the fish looked like once they'd cut it open to look at the liver, heart and other organs. It was fascinating, even after the fish had been dead for a few minutes, you could still see heart pumping.

Thursday afternoon and Friday I did more typical work in the lab. We looked at fish embryos under the microscope and judged their heart development after they had been induced with different chemicals. I also spawned fish again and screened the eggs, pulling out the good ones to use in my experiment. Friday afternoon I dosed those eggs, and tomorrow, Monday, I'll get to look at their development.

Hey everyone! My name is Susannah Butters and I'm a rising junior at Carolina Friends School, a small Quaker school in Durham. This summer I will be working in Dr. Richard Di Giulio's lab in the Nicholas School of the Environment and Earth Sciences.

It has been a whirlwind first week. On Monday, the first day, instead of being picked up by the usual one escort to take me to the lab I'd be working in, four people arrived. They were all quite enthusiastic and got me excited about spending the summer working with them. Once I arrived at the lab, I was given a tour and an introduction to what they do and what I'd be studying for the next seven weeks. They research how polycyclic aromatic hydrocarbons (PAHs) affect the aryl hydrocarbon receptor (AHR) pathway in zebrafish and killifish.

By the second day, they had me working with a graduate student studying zebrafish hatchlings. These hatchlings had been dosed with PAHs and we looked at them under a microscope, noting the impact of the PAHs. We were especially focused on the zebrafishes' development of pericardial edemas from their exposure to PAHs.

Another day I got to help spawn killifish. To do this, you hold the females and rub their stomachs with your thumb to make their eggs come out onto your gloved hand. You add the eggs to a jar and then fertilize them with a male fish. The first time that I got to help with this though, we came across a surprise. The person I was working with, Cole, was spawning a female fish and got two already fertilized eggs among many regular ones. Everyone in the lab assured me that this never happens. Eggs are supposed to be fertilized only after they leave the mother. They looked at these two eggs under a microscope and figured that it had been about a week since they were fertilized. It's a mystery to everyone in the lab as to how this happened and I'm interested to see what we discover about them as tests are run as they get older. For now, they are living in the lab and have been nicknamed Jesus Fish 1 and Jesus Fish 2.

I'm very excited to be working in this lab. It's already proven to be a very interesting week.