Genetic and developmental relationships of testis and eye colour inDrosophila pseudo-obscura

Summary

1. Testes of adults and pupae of wildtype and various eye-colour mutant types ofDrosophila pseudo-obscura have been examined.

2. Histological sections show that pigment is of a granular nature in the testes ofD. pseudo-obscura.

3. The time of pigment deposition in the testes ofD. pseudo-obscura practically coincides with the late phase of eye-pigment development. Testis pigment appears a few hours earlier than late-phase eye pigment.

4. The amount of pigment in the testes of the various mutants is correlated with the amount of pigment laid down in the eye during the late phase of development and is in no way related to the amount deposited in the eye during the early phase of development.

5. Genes which affect late-phase pigment in the eye have the same effect upon testis colour. Those which affect late-phase eye pigment quantitatively also affect the testis pigment quantitatively; sepia (se), which has a qualitative effect upon late-phase eye pigment, has a similar qualitative effect upon testis pigment.