Mosaic Analysis of a Drosophila Clock Mutant

Gynandromorphs that showed mosaicism for an X chromosome carrying a short-period (pers) circadian clock mutation and several visible mutations were produced by two different methods. A blastoderm fate map of cuticle markers as well as the focus of the clock mutation were constructed with the aid of a least-squares computer program. The focus location was consistent with a brain location for the clock. Some flies with mosaic heads had activity rhythms with both male and female components, suggesting that the oscillators in the two halves of the brain were of different genotype and could function independently.