Skip to main content MCC Crescent Shape Search rss Facebook Twitter Youtube Instagram chevron pointing down

Fly Eye - Sepia Pigment

Results for Sepia

Pigments of sepia

Figure 1.

Figure 1. Result of sepia X cinnabar cross. A female homozygous for sepia and cinnabar is pictured. These double mutations were extremely rare and only females were found. The fly can be compared to a sepia chromatogram. Cinnabar blocks brown pigment production, but the pteridines present in sepia give the eye a brownish appearance which darkens with age.

ChromSepiaCinmf14.jpg

Homozygous sepia X cinnabar female

Figure 2.

Results of sepia X vermilion cross. Vermilion blocks all brown pigment production and sepia prevents production of orange drosopterin pigment but not all pteridine pigments, giving rise to a brownish appearance which darkens with age.

Sepia Female chromatogram

Figure 3.

These sepia X vermilion F3 double homozygotes are younger than the flies in Figure 2, and hence are lighter in color.

Vermillion X sepia f3 double homozygous female left and male right

Sepia crossed with cinnabar

Table 1.
Results of red, sepia, and cinnabar reciprocal crosses. No sex-linkage is seen.

P red eye (f) DD X sepia eye (m) dd
F1 red eye (f) Dd X red eye (m) Dd

 1.

      Observed Expected
F2 red eye (f) D_ 66 64.5
  red eye (fm) D_ (male and females included in above)
  sepia eye (f) dd 20 21.5
  sepia eye (m) dd (male and females included in above)
  TOTAL   86

CHISQ.TEST = 0.709 for hypothesis that sepia segregates autosomally


 2.

P sepia eye (f) dd X red eye (m) DD
F1 red eye (f) Dd X red eye (m) Dd

 

      Observed Expected
F2 red eye (f) D_ 55 50.2
  red eye (m) D_ (male and females included in above)
  sepia eye (f) dd 12 16.8
  sepia eye (m) dd (male and females included in above)
  TOTAL   67

CHISQ.TEST = 0.176 for hypothesis that sepia segregates autosomally

 3.

P red eye (f) NN X cinnabar eye (m) nn
F1 red eye (f) Nn X red eye (m) Nn

 

      Observed Expected
F2 red eye (f) N_ 95 114
  red eye (m) N_ (male and females included in above)
  cinnabar eye (f) nn 57 38
  cinnabar eye (m) nn (male and females included in above)
  TOTAL   152

CHISQ.TEST = 0.000 for hypothesis that cinnabar segregates autosomally

 4.

P cinnabar eye (f) nn X red eye (m) NN
F1 red eye (f) Nn X red eye (m) Nn

 

      Observed Expected
F2 red eye (f) N_ 129 131.2
  red eye (m) N_ (male and females included in above)
  purple eye (f) nn 46 43.8
  purple eye (m) nn (male and females included in above)
  TOTAL   175

CHISQ.TEST = 0.701 for hypothesis that cinnabar segregates autosomally

 5.

P sepia eye (f) ddNN X cinnabar eye (m) DDnn
F1 red eye (f) DdNn X red eye (m) Ddnn

 

      Observed Expected
F2 red eye (f) D_N_ 68 73.7
  red eye (m) D_N_ (male and females included in above)
  sepia eye (f) ddN_ 32 24.6
  sepia eye (m) ddN_ (male and females included in above)
  cinnabar eye (f) D_nn 30 24.6
  cinnabar eye (m) D_nn (male and females included in above)
  yellowish (f) ddnn 1 8.2
  unknown (m) ddnn 0    (expected for both sexes above)
  TOTAL   131

CHISQ.TEST = 0.017 for hypothesis that sepia and cinnabar segregate autosomally and independently to produce a fourth phenotype

 6*.

P cinnabar eye (f) DDnn X sepia eye (m) ddNN
F1 red eye (f) DdNn X red eye (m) DdNn

 

      Observed Expected
F2 red eye (f) E_P_ 67 73.7
  red eye (m) E_P_ (male and females included in above)
  sepia eye (f) eeP_ 35 24.6
  sepia eye (m) eeP_ (male and females included in above)
  cinnabar eye (f) E_pp 29 24.6
  cinnabar eye (m) E_pp (male and females included in above)
  yellowish (f) eepp 0 8.2
  unknown (m) eepp 0 (expected for both sexes above)
  TOTAL   131

*Note: counting of an additional approximately 230 flies revealed 1 yellowish female.

CHISQ.TEST = 0.003 for hypothesis that sepia and cinnabar segregate autosomally and independently to produce a fourth phenotype

Sepia crossed with vermilion

Table 2. Results of red, vermilion, and sepia reciprocal crosses. Sex-linkage is observed.

1.

P red eye (f) XLXL X vermilion eye (m) XlY
F1 red eye (f) XLXI X red eye (m) XLY

 

      Observed Expected
F2 red eye (f) XL_ 83 92.5
  red eye (m) XLY 62 46.2
  vermilion eye (f) XIXI 0 0
  vermilion eye (m) XlY 40 46.2
  TOTAL   185

CHISQ.TEST = 0.027 for hypothesis that vermilion is sex-linked

2.

P vermilion eye (f) XIXI X red eye (m) XLY
F1 red eye (f) XLXI X vermilion eye (m) XIY

 

      Observed Expected
F2 red eye (f) XL_ 49 54
  red eye (m) XLY 57 54
  vermilion eye (f) XIXI 58 54
  vermilion eye (m) XlY 52 54
  TOTAL   216

CHISQ.TEST = 0.801 for hypothesis that vermillion is sex-linked

3.

P vermilion eye (f) XlXl DD
X sepia eye (m) XLY dd
F1 red eye (f) XLXi Dd X vermilion eye (m) XIY Dd

 

      Observed Expected
F2 red eye (f) XL_D_ 42 36.6
  red eye (m) XLY_D_ 32 36.6
  vermilion eye (f) XlXl D_ 60 36.6
  vermilion eye (m) XIY D_ 30 36.6
  sepia eye (f) XLXL dd 12 12.2
  sepia eye (m) XLY dd 17 12.2
  yellowish (f) XlXl dd 2 12.2
  yellowish (m) XlY dd 0 12.2
  TOTAL   195

CHISQ.TEST = 0.000 for hypothesis that sex-linked vermillion and sepia segregate independently to produce a fourth phenotype

 4.

P sepia eye (f) XLXL dd
X vermilion eye (m) XIY DD
F1 red eye (f) XLXi Dd X red eye (m) XLY Dd

 

      Observed Expected
F2 red eye (f) XL _D_ 16 10.9
  red eye (m) XLY D_ 1 5.4
  vermilion eye (f) XlXl D_ 0 0
  vermilion eye (m) XIY D_ 5 5.4
  sepia eye (f) XLXL dd 1 3.6
  sepia eye (m) XLY dd 5 1.8
  unknown (f) XlXl dd 0 0
  yellowish (m) XlY dd 1 1.8
  TOTAL   29

CHISQ.TEST = 0.016 for hypothesis that sex-linked vermillion and sepia segregate independently.to produce a fourth phenotype

Position of sepia

Sepia crossed with brown

Table 3. Results of red (wild), sepia, and brown reciprocal crosses. 

1.

P red eye (f) BB X brown eye (m) bb
F1 red eye (f) Bb X red eye (m) Bb

 

      Observed Expected
F2 red eye (f) B_ 63 61.5
  red eye (m) B_ (males and females included above)
  brown eye (f) bb 19 20.5
  brown eye (m) bb (males and females included above)
  TOTAL   82

CHISQ.TEST =0.702 for hypothesis that brown segregates autosomally

2.

P brown eye (f) bb X red eye (m) BB
F1 red eye (f) Bb X red eye (m) Bb

 

      Observed Expected
F2 red eye (f) B_ 44 42.8
  red eye (m) B_ (males and females included above)
  brown eye (f) bb 13 14.2
  brown eye (m) bb (males and females included above)
  TOTAL   57

CHISQ.TEST = 0.713 for hypothesis that brown segregates autosomally

3.

P sepia eye (f) ddBB X brown eye (m) DDbb
F1 red eye (f) DdBd X red eye (m) DdBb

 

      Observed Expected
F2 red eye (f) D_B_ 67 64.7
  red eye (m) D_B_ (males & females included above)
  sepia eye (f) ddb_ 18 21.6
  sepia eye (m) ddB_ (males & females included above)
  brown eye (f) D_bb 30 21.6
  brown eye (m) D_bb (males & females included above)
  brown (f) ddbb unknown 7.2
  brown (m) ddbb (expected for both sexes above)
  TOTAL   115

CHISQ.TEST = 0.694 for hypothesis that brown and sepia segregate autosomally and independently so that double homozygotes are brown

4.

P brown eye (f) DDbb X sepia eye (m) ddBB
F1 red eye (f) DdBb X red eye (m) DdBb

 

      Observed Expected
F2 red eye (f) D_B_ 70 60.8
  red eye (m) D_B_ (males & females included above)
  sepia eye (f) ddb_ 15 20.2
  sepia eye (m) ddb_ (males & females included above)
  brown eye (f) D_bb 23 20.2
  brown eye (m) D_bb (males & females included above)
  brown (f) ddbb unknown 6.8
  brown (m) ddbb (expected for both sexes above)
  TOTAL   108

CHISQ.TEST = 0.190 for hypothesis that brown and sepia segregate autosomally and independently so that double homozygotes are brown

 Sepia crossed with sepia-rosy

Table 4. Results of sepia and sepia-rosy cross

1.

            F1         red eye (f)       DdRr               X         sepia-rosy eye (m)                         ddrr

 

                                                                        Observed                                 Expected

Test cross offspring

           

            F2         red eye (f)       D__R__           37                                            22.4

 

                        red eye (m)     D__R__           (both sexes included above)

 

                        sepia eye (f)    ddR__             51                                            67.1 

 

                        sepia eye (m)  ddR__             (both sexes included above)

 

                        rosy eye(f)    D__rr                 48                                            67.1

  

                        rosy eye(m)  D__rr                 (both  sexes included above)

 

                        dark brown(f)  ddrr                 43                                            22.4 

 

                        dark brown(m)ddrr                 (both sexes included above)

 

                        Total                                       179

CHISQUARE.TEST=0.0000 if 25% crossover between sepia and rosy is expected. The results for sepia and sepia-rosy (dark brown) are not pooled.

CHISQUARE.TEST=0.0005 if 25% crossover between sepia and rosy is expected. The results for sepia and sepia-rosy are pooled because both phenotypes are dark brown and difficult to distinguish.

Dr. Stephen Reinbold

Last Modified: 6/1/18