Biology 22

DrosophilaIdentification of various phenotypes.

Outline Brief description of Drosophila phenotypes and life cycle

1-Experiment 1: collection of data related to gender and body color

2-Experiment : 3 point Test Cross

How to study keep your flies still during the identification.

Reference for Pictures:

Carolina Drosophila melanogster Manual (45-2620)

Published: Carolina Biological Supply Company

Based on research of Dr. Thomas Hunt Morgan

1866-1945

The life Cycle

Life Cycle: Drosophila melanogaster

Eggs: contain filaments

2 molting phases “instars”

Life cycle is 10 days

Fruity Fly Egg and Larva

Fruit Fly Pupa and Adult

1- EXPERIMENT: Identification of:

Gender

Body Color

Wild Type Versus Mutants

Body Color

Wild type: BeigeMutant: Yellow body

Parental phenotypes Experiment: body color

A= female: wt (beige) B=female: wt (beige) C=male: wt (beige) D=female: mutant (yellow) E=male: mutant (yellow)

Fruit Fly Body Color

Sex combs: Male Drosophila

Female and Male Fruit Flies

Abdominal segements

7 segments to female abdominal segments

5 segments to male abdominal segments

Male body size is smaller than female

But the “last” abdominal segment is larger in male

2- Experiment: 3 point test cross:

Experiment 2 3 point test cross

Eye color Body color Wing length

3 point test cross for:

1. Body Color

2. Wing length

3. Eye Color

♦ Wt vs. Mutant

Beige (bl+) vs. Black (bl)

Long(vg+) vs. Vestigal(vg)

Brick red (br+) vs. brown (br)

Crosses:

Female Males

Males and female progeny from this F2 cross are your 3 point test cross results!

Xbl vg bw

bl vg bw

bl+ vg+ Bw+

bl vg bw

There are all sorts of eyes!

Eyes

You will have only red eyes (wt)

Fruit Fly Wings

Nap TimeTriethylamine

How to anesthetize a fly

How to use the Napper

View the Fruit Fly

You will record class data

After counting the crosses record the data on the class spreadsheet