Loss of a paternal chromosome causes developmental anomalies among Drosophila hybrids

Hybrids between Drosophila virilis and D. lummei suffer from developmental anomalies. Previous reports also suggest that these hybrids lose the D. lummei sixth chromosome early in development. Genetic and cytological data presented here confirm the loss of the microchromosome from both the soma and the germ-line of these hybrids and provide strong evidence that this loss causes the hybrid developmental anomalies.