The generation and analysis of deficiencies within a small genomic region on the X chromosome of Drosophila melanogaster containing two genes, enhancer of rudimentary and CG15352.

The enhancer of rudimentary gene, e(r), encodes a 104-amino-acid, highly conserved transcription cofactor. Hypomorphic mutations of e(r) show an enhancement of a hypomorphic rudimentary mutant wing phenotype. These mutants in a wild-type background are viable, fertile, and morphologically wild-type.