Drosophila melanogaster

1-2 days 4 days 1-2 days First instar 1-2 days 1-2 days Third instar Second instar 1-2 days

pupae Small, oval, two filaments at one end, laid on the surface of the food Instar/larvae Worm-like, eats constantly, burrows in food, black mouth parts, sheds skin twice as it grows. egg Larva climbs up side of tube to pupate, Outer covering harder and darker, you can see eyes, legs, wings…the darker they get the closer they are to hatching. pupae

Adult Emerge from case, fragile, light in color, the lighter the newest hatched, wings folded at first, darkens in a few hours, live about 5-6 weeks. Females can mate after emerging from case in 10-12 hours. She can store sperm in receptacles every mating for her entire lifespan, eggs are fertilized as they are laid. Adult

Male Female Sex combs *concentrated dark banding with a solid tip on abdomen *smaller *Larger *striped abdomen *broader abdomen

Four chromosomes : 3 Autosomal and one sex chromosome

Mating Behavior

A Female laying an egg

Wild type (+)

Red round eye Normal long wing antenae Tan body hair

Vestigal wing (can’t fly)

There are many mutations

Caring for Fruit flies

Supplies needed Special tubes Yeast to feed adults Petri dish Paint brushes

Paint brush to move flies Label tubes Tube with food -one scoop food To equal water (potato and banana meal) Sponge cork

Sponge cork to keep flies In and still exchange gasses Formula blue food: blue dye to see white larva easier, larva eat and tunnel in it Yeast sprinkled on food for the adults

Anesthetic to put flies to sleep in order to view and record traits. *the pipe cleaner “wand” in to the flynap and insert in a sponge to hang in the flynap tube. *flies to be “napped” need to be transferred to a dry tube without food before “napping”. *smells interesting, will not put you to sleep!

Putting flies to sleep

Putting the “sleeping” flies on a clean dry dish

“sleeping” flies in the dish to view

Separating flies gently with a paintbrush

Viewing flies with a stereoscope

You must use a stereoscope to determine sex of the flies

Female Male

Be sure to label all tubes

Fly trap: jar/beaker with paper funnel and vinegar attracts escapees.

Alcohol rubbing Fly jar: to place flies no longer needed *please bring a jar- one per group

What will you be doing? *Testing one variable on gender development *investigating your topic: background research *Designing a procedure to test your hypothesis *determining sex of fruit flies and collecting data, analyzing data, writing a result and conclusion *designing a display board of your project

Problem Does ____________affect gender development in Drosophila melanogster? *Temperature *Acidity *Amount of light

Hypothesis *after a little research, make an educated guess to your problem statement. If _______________, then ____________.

Designing an Experiment Control Variable Constants Sample size Bias free 6. Data

Today *Investigate the flies with a stereoscope. *try to separate flies into male and female, move them gently with the paint brush