Isolation of Anatomical Brain Mutants of Drosophila by Histological Means

Abstract Due to its small size Drosophila melanogaster can conveniently be used in screening experiments for anatomical brain mutants. A simple method has been designed which allows to process up to 20 identifiable flies as a single preparation in a standard histology routine. Anatomical brain mutants are very frequent. Over 60 mutants were obtained from the inspection of about 3000 brains. So far genetic variations of brain structure fall into 4 classes: (1) “low fidelity” mutants in which brains are less precisely built; (2) “brain shape” mutants with globally or partially reduced brains; (3) “architectonic” mutants which show constructional defects mainly in the repetitive structures of the brain and (4) “vacuolar” mutants with globular “holes” in certain areas of the brain. These mutant classes obviously reflect different aspects of brain development like cell proliferation (2), “wiring” (3) and cell death (4). Some of the mutants may prove to be useful in anatomical, physiological or genetic brain research.