Additive gene actions on the fiber number in the anterior optic tract of Drosophila melanogaster.

The influence of mutations in seven neurological genes on the number of fibers in the anterior optic tract (AOT) of Drosophila melanogaster has been investigated. It is shown that the number of fibers in the AOT can be drastically reduced in single and especially in multiple mutants. However, no evidence for synergistic interactions between the sample of mutations used in the sine oculis (so), reduced optic lobes (rol), minibrain (mnb), and small optic lobes (sol) genes was obtained at the level of the AOT. The rolKS222 and so mutations eliminate similar fiber sets in the AOT, which are distinctly different from those eliminated by solKS58 and mnb1.