13 tests to explain biology through Drosophila

1
13 tests to explain biology through Drosophila

• The aim of this presentation is to bring you easy
  experiments that we designed in the lab to help
  with understanding some of the concepts of
  biology.

2
1-Testing adult behavior

• T-mazes are used in labs everyday to test
  different fly preferences.
• They could be used for testing different
  behavior luminosity, color, smell, gravity.

The basic T-maze
entry
3
2-Testing larval learning

• Learning is a concept which is still not
  completely understood by biologist however it is
  integrant and essential part of biology, and
  life.
• One can devise a simple test to show this
  concept. This test consist of teaching the larvae
  a simple concept very similar to Pavlovs dog.

4
2-Learning Behavior

• This test was originally designed for olfaction,
  by Dr. Scherer in Germany two years ago, and can
  very easily be performed as a visual assay

Learning Part
Test
Control
x 10
5
3-Neural Response

• One of the simplest test that can be perform with
  a fly to show the students direct neural response
  is to use a hot or cold object and touching the
  larvae with it. Students could also make visual
  maps of the response depending on the strength of
  the response, the kind of response, or at what
  temperature a response is observed.

6
4-Understanding ecology through Drosophila

• Right now, all of you are using a strain of
  Drosophila named CS for Canton S thus meaning
  that they come from the Canton Region of China
  (Southeast China). One experiment could be to ask
  the students to learn about the Southeast region
  of china by looking at information online and in
  different books. Then they could design an
  optimal environment for the animals.
• After creating this environment the students
  could look at the size and number of animals they
  begin with and see how this will change at the
  same time the week after.

• Students could think concepts such as
  temperatures, different foods, day/light
  regiments, humidity, space (flies might like
  bigger tubes).

7
5-Acclimation

• Acclimation is when a animal adapts itself to
  changes in a laboratory set-up. This can be shown
  in different ways. One could use the same set-up
  as for the hot and cold test and see if the
  animal will continually respond to hot stimuli.
• However, we could go one step further. High doses
  of caffeine, nicotine, salt, or acid can cause
  the animals to go in tetany. Maybe, if students
  would give small dosages of nicotine on the
  Tuesday class, the larvae would be able to
  receive stronger doses on Thursday without going
  in tetany.

8
6-Evolution Survival of the fittest

• Another possible experiment is to place nicotine,
  pesticide, salt, acids in the fly tube and
  observe which fly survive the test whether they
  can handle stronger doses of nicotine, pesticide,
  salt. Can be extended to different mutant
  strains.

9
7-Genetic variation

• Collecting flies through ripening fruit
  (e.g.bananas), then the flies can be passed out
  and observed for differences in the appearance
  (or body parts) by the students or observe larvae
  and pupae.

10
8-Predator/Prey interaction

• Venus Fly Traps can be brought to the lab and
  students can observe the interaction of the two
  species.
• Venus Fly Trap can be bought on e-bay pretty
  easily.

11
9-Larval Behavior using food dye

• Food dyes have two advantages they allow for the
  explanation of the GI track and they can also be
  used for testing behavior. One simple test could
  be to set the fly on a dish containing different
  food with different dyes and see how many flies
  have what color after a couple of minutes.

12
10-Cardiac activity

• One simple set-up is to glue a larvae down using
  Krazy-glue or another kind of liquid glue (double
  stick tap and physical blocking also work), once
  the animal is down the cardiac activity (heart
  rate) can be observed and also can be altered
  using mild acids, sugars, salts, or even CO2
  (carbon dioxide) can completely stop the heart
  beat for a certain time.

13
11-Verniers Probe

• The Verniers Probe can be used to detect CO2
  emission from the larvae. Temperature variation
  can be induced to test for difference in CO2
  emission.

14
12-Anne Coopers Column

• The column allow the implementation of one
  variable and to record an actual level of
  preference.
• Light is not the only possible test. Smells can
  be introduced. Another concept can be to test how
  fast they go up the tube normally and how long it
  would take them if the tube is wet, oily, sticky,
  etc.

15
13-Vortexs Test

• Sensory interpretation of outside movement. In
  this test students can observe the larvae first
  not moving and then regaining its abilities.
  Topics such as the human inner ear can be
  introduced that way.

16
Brain-storm