The Tofu mutation compensates for the loss of functional BEAF in Drosophila

Compensatory mutations offer clues to deciphering the role of a particular protein in cellularprocesses. Here we investigate an unknown compensatory mutation, present in the BEAFNP6377fly line, that provides sufficient rescue of the ovary defect phenotype caused by null BEAFalleles to allow maintenance of fly stocks lacking BEAF. We call this mutation Tofu. We employboth classical genetics and genomic sequencing to attempt to identify the mutation. We findevidence that points to a mutation in a predicted Polycomb response element upstream of theribbon gene, which may lead to aberrant rib expression.