TRAITS

+=Wild Type= normal wing / eye red

ap=apterous wing = no wing or only wing bud

vg=vestigial wing= crinkled wing

B=bar eye= small eye (bar or rectangle shaped)

ey=eyeless = no eye or extremely small red dot

eb=ebony= ebony (dark) almost black body

sn=singed bristles= “burnt” looking bristles on head

w=white eye = white eye

se=sepia eye = dark brown

bw=brown eye = light brown eye

st=scarlet eye= bright red (brighter than wild type)

dp=dumpy= scalloped wings

Below are the results gathered from Fruit Fly Projects of Kenston students to date. Your mission is to evaluate and interpret these results in order to determine what type of cross each is for example it might be a simple: Dominant/Recessive; or Sex-Linked; Incomplete Dominance; Genetic Linkage, Gene Interaction (epistasis), etc.; or a combination of these.

Hints for Success:

1)When counting – carefully separate male and females / Compare male / female numbers (if similar – you can assume that it is NOT sex-linked)

2)Compare total phenotypic ratios

3)Evaluate whether it is a 3:1 ratio in a monohybrid cross/ or 9:3:3:1 in a di-hybrid cross (if you get close to this ratio – this tells you that it is a simple dominant recessive cross)

4)If you do NOT get a 3:1 ratio or a 9:3:3:1 in a di-hybrid that tells you that something else is going on (linkage = located on same chromosome; epistasis, etc).

5)How can you tell if it is “Sex-linked”? If in the F1 there are males that show up with the recessive trait (when female parent is recessive)

What is a trait shows up that was not like one of the parentals? This could be incomplete dominance (blending of the two traits), or epistasis (one gene controls expression of another)

White x Wild

Mutation = w / Wild Males ♂ / Wild Females ♀ / White Male ♂ / White Female ♀
WHITE EYES / F1
Wild ♂ x White ♀ / 0 / 2500 / 2200 / 0
F2
Wild ♂ x White ♀ / 1800 / 1700 / 1780 / 1675
Ratio:
Mutation / Wild Males ♂ / Wild Females ♀ / White Male ♂ / White Female ♀
F1
Wild ♀ x White ♂ / 4200 / 3900 / 0 / 0
F2
Wild ♀ x White ♂ / 2200 / 4050 / 2100 / 0
Ratio:

Vestigial/Brown x Wild

Mutation = vgvg/bwbw / Wild / Wild ♂ / Wild / Wild ♀ / Wild / Bw♂ / Wild / Bw♀ / Vg / Wild ♂ / Vg / Wild ♀ / Vg / Bw♂ / Vg / Bw♀
VESTIGAL/BROWN / F1
Wild ♂ x vg/bw♀ / 3250 / 3110 / 0 / 0 / 0 / 0 / 0 / 0
F2
Wild ♂ x vg/bw♀ / 310 / 330 / 110 / 140 / 130 / 120 / 320 / 325
Ratio:
Mutation / Wild / Wild ♂ / Wild / Wild ♀ / Wild / Bw♂ / Wild / Bw♀ / Vg / Wild ♂ / Vg / Wild ♀ / Vg / Bw♂ / Vg / Bw♀
F1
Wild ♀ x vg/bw♂ / 2200 / 2400 / 0 / 0 / 0 / 0 / 0 / 0
F2
Wild ♀ x vg/bw♂ / 340 / 350 / 150 / 145 / 140 / 125 / 335 / 340
Ratio:

Apterous/Sepia x Wild

Mutation = apap/sese / Wild / Wild ♂ / Wild / Wild ♀ / Wild / Sepia ♂ / Wild / Sepia ♀ / Apt / Wild ♂ / Apt / Wild ♀ / Apt / Sepia ♂ / Apt / Sepia ♀
APTEROUS/SEPIA / F1
Wild ♂ x apt/se ♀ / 1500 / 2200 / 0 / 0 / 0 / 0 / 0 / 0
F2
Wild ♂ x apt/se ♀ / 2750 / 2840 / 850 / 890 / 880 / 920 / 305 / 315
Ratio:
Mutation / Wild / Wild ♂ / Wild / Wild ♀ / Wild / Sepia ♂ / Wild / Sepia ♀ / Apt / Wild ♂ / Apt / Wild ♀ / Apt / Sepia ♂ / Apt / Sepia ♀
F1
Wild ♀ x apt/se ♂ / 1800 / 1990 / 0 / 0 / 0 / 0 / 0 / 0
F2
Wild ♀ x apt/se ♂ / 450 / 400 / 110 / 140 / 120 / 145 / 40 / 45
Ratio:

Scarlet x Brown

Mutation = stst/bwbw / Wild / Scarlet / Brown / White
SCARLET/BROWN / F1
Scarlet♂ x Brown♀ / 1500 / 0 / 0 / 0
F2
Scarlet♂ x Brown♀ / 6635 / 2020 / 2190 / 725
Ratio:
Mutation / Wild / Scarlet / Brown / White
F1
Scarlet♀ x Brown♂ / 3400 / 0 / 0 / 0
F2
Scarlet♀ x Brown♂ / 4750 / 1200 / 1620 / 500
Ratio:

Bar x Wild

Mutation = B / Wild ♂ / Wild ♀ / Kidney ♂ / Kidney ♀ / Bar ♂ / Bar ♀
BAR / F1
Wild ♂ x B/B ♀ / 0 / 0 / 0 / 701 / 683 / 0
F2
Wild ♂ x B/B ♀ / 247 / 0 / 0 / 238 / 270 / 252
Ratio:
Mutation / Wild ♂ / Wild ♀ / Kidney ♂ / Kidney ♀ / Bar ♂ / Bar ♀
F1
Wild ♀ x B/B ♂ / 822 / 0 / 0 / 799 / 0 / 0
F2
Wild ♀ x B/B ♂ / 225 / 198 / 0 / 200 / 231 / 0
Ratio:

If you are doing a cross that is not listed here (ebony x sepia); that means that you are the first class to do that cross. Please ask other groups for their results and use the “class” as the “group”. Compare YOUR results with the class.