Retrotransposons Are the Major Contributors to the Expansion of the Muller F Element.

The discordance between genome size and the complexity of eukaryotes can partly be attributed to differences in repeat density. The Muller F element (∼5.2 Mb) is the smallest chromosome in , but it is substantially larger (>18.

A dual function of V0-ATPase a1 provides an endolysosomal degradation mechanism in Drosophila melanogaster photoreceptors.

The vesicular adenosine triphosphatase (v-ATPase) is a proton pump that acidifies intracellular compartments. In addition, mutations in components of the membrane-bound v-ATPase V0 sector cause acidification-independent defects in yeast, worm, fly, zebrafish, and mouse. In this study, we present a dual function for the neuron-specific V0 subunit a1 orthologue v100 in Drosophila melanogaster.

Drosophila acinus encodes a novel regulator of endocytic and autophagic trafficking.

Endosomal trafficking affects many cellular pathways from cell signaling to metabolism, but little is known about how these effects are coordinated. In a genetic screen for mutants affecting endosomal trafficking, we identified Drosophila acinus (dacn; hook-like). Its mammalian homolog Acinus has been implicated in RNA processing and chromatin fragmentation during apoptosis.

Drosophila Vps16A is required for trafficking to lysosomes and biogenesis of pigment granules.

Mutations that disrupt trafficking to lysosomes and lysosome-related organelles cause multiple diseases, including Hermansky-Pudlak syndrome. The Drosophila eye is a model system for analyzing such mutations. The eye-color genes carnation and deep orange encode two subunits of the Vps-C protein complex required for endosomal trafficking and pigment-granule biogenesis.

Specification of cell fates within the salivary gland primordium.

The Drosophila salivary gland is a simple tubular organ derived from a contiguous epithelial primordium, which is established by the activities of the homeodomain-containing proteins Sex combs reduced (SCR), Extradenticle (EXD), and Homothorax (HTH). EGF signaling along the ventral midline specifies the salivary duct fate for cells in the center of the primordium, while cells farther away from the source of EGF signal adopt a secretory cell fate. EGF signaling works, at least in part, by repressing expression of secretory cell genes in the duct primordium, including fork head (fkh), which encodes a winged-helix transcription factor.