Week four: FlyVac Machine

Hi everyone. This is Sandra again. I am writing my forth week in  the Evolution and Behavior Lab in Harvard University.This week is quite exciting for me. I've finally got the chance to use the FlyVac machine to measure the flies' photo-tactic behavior!!

FlyVac machine and the computer

The data in the computer

The process was doing it was actually not as difficult as I thought. As you see in the picture, the FlyVac machine is connected to a computer that is used to collect the data. Lighter blue means a light choice and the darker blue means the dark choice. The white column is used for labeling the specific type of each fly. (Enriched or controlled, Canton.S or DGRP, Female or male). After doing the labeling and set up the computer, I have to load the flies that were in the second-staging tubes (Since they already been tested in Y-maze) into the choice tubes. There are 32 choice tubes in the FlyVac.Once the flies finished 40 choices (complete line in the computer), I would use a tube to suck the fly out(which is still alive inside the choice tube), and put another fly into the choice tube.

The tube I used to load the flies in and suck them out

The place where the flies end their life.....

In this coming week I will start analyzing the data in both Y-maze and FlyVac machine. I can't wait!! Hope everyone is doing fine in their labs too!

Week two and three--The staging process and the Y-maze experiment

Hello Everyone. My name is Sandra Ho and I am writing about my second and third week in the Evolution and Behavior Lab at Harvard University.

My second week was quite easy and simple. On the first two days I created more enriched and standard tubes for all types of flies for trials, which included: Canton.S and DGRP( include 45,105, 796 and 535). The flies in DGRP are not genetically identical as some of them exhibits higher variability and some of them exhibits lower variability. During the middle of the week, I noticed a lot of the flies in the trial tubes started to hatch. Ben suggested me to put them in the staging tubes for five days and then they would be available to test for behavior. I put 10 male and 10 female in each of the enriched tubes and 20 males or 20 females in each of the control tubes for staging. He also gave me a suggestion for my project: collect flies in outdoor by using traps. He thought it was a good idea to test them because those flies are wild types and the environment they used to live is a lot different from the flies in our lab, hence the results might be different. Therefore, I made five traps( put a paper funnel in the opening of the test tube which contains fly food) and put them behind a bush near my dorm.

The third week I finally got the chance to do the Y-maze experiment! Basically, the Y-maze experiment is to quantify left and right turning of the flies. An individual fly is placed in a Y-shaped maze on top of a light box, allowed to walk freely for two hours, and the X-Y position of the fly’s centroid  is tracked by a camera. The first thing I had to do was to make the flies asleep by using CO2 gas and use a brush to put them into a tray that consist of 120 individual Y-mazes. One fly in each maze and each maze is covered by a lid.This set up allows 120 flies to be run in parallel, and each of which makes hundreds of turns during the two-hour experiment Then I had to put the tray inside the light box and put all the information of the flies in the computer that is connected to the light box. And finally, when I clicked the button "Start Data Collection", the computer would then start collecting data!

This is the light box used for the Y-maze experiment.

This is the computer that is used for data collection.

And those are my trials and stocks of flies.

For the coming week, I will start analyze the data with Ben because there are soon enough flies that have been tested for behavior. I am really excited about it and I hope everyone is doing well in their lab too!

Week 1-- The enrichment process of fruit flies

Hello everyone.This is Sandra. The first week of my lab (The Evolution and Behavior Lab) in Harvard University was awesome.I am working directly with my PI Dr de Bivort,( but he likes me to call him Ben) and he is very easy going, helpful and communicative. I am lucky to have this chance to work with him.

Day 1

Ben gave me a tour around the Rowland Institute where my lab is located . He went through all the safety instructions in the lab and he introduced two machines that I would use in the following weeks: FlyVac and the Y-maze machine. The FlyVac is used to measure the phototactic personality while the Y-maze is to measure the locomotive behavior of fruit flies.  

 

Day 2

In the  morning I need to go for shopping at the Central Square in Cambridage area. Since my project is " How environmental enrichment affect the behavioral diversity of genetically identical fruit flies", Ben asked me to make an enrichment plan for the fruit flies and go to the art store in Central Square to buy all the supplies which could be used for enrichment. I bought some pipe cleaners, small poms poms, drinking strews, thin sticks of balsa wood and some small tubes that fruit flies could climb on. 

 

Day 3

 I had a practice of using the microscope to separate female fruit flies from male fruit flies, virgins from non virgins. It was really amazing. After that, Ben asked me to read the first chapter of the book called "Fly Pushing". It is useful for me to learn about the basic fly husbandry and steps for the collection of flies for crosses. After I finished the first chapter, I started making the trials for my experiment.There are same number of enrichment tubes and control tubes, and there are three females and two males in each tube. After the fruit flies in all the tubes were awake, I put them into the fridge which is in 25 degree and 60% Relative Humidity. 

 

Day 4

I learnt how to expand the fruit flies and created more trials for my experiment. At the end of the day, Ben gave me a suggestion: create two extreme conditions of environment enrichment, one is what I have been doing so far (enrichment in the tube) and other one is to use a tall big cage. I need to see how the results differ from each other.

 

Day 5 and Day 6

I was simply doing the expansion of the fruit flies and more creation of the trials because I was waiting for the more supplies for the enrichment (big cage) to be delivered.

Overall the first week is a fruitful week to me. I am looking forward to using the two machines and collecting data in the coming weeks!