The astrocyte-enriched gene <i>deathstar</i> plays a crucial role in the development, locomotion, and lifespan of <i>D. melanogaster</i>

The <i>Drosophila melanogaster</i> brain is a complex organ with various cell types, orchestrating the development, physiology, and behaviors of the fly. While each cell type in <i>Drosophila</i> brain is known to express a unique gene set, their complete genetic profile is still unknown. Advances in the RNA sequencing techniques at single-cell resolution facilitate identifying novel cell type markers and/or re-examining the specificity of the available ones. In this study, exploiting a single-cell RNA sequencing data of <i>Drosophila</i> optic lobe, we categorized the cells based on their expression pattern for known markers, then the genes with enriched expression in astrocytes were identified. <i>CG11000</i> was identified as a gene with a comparable expression profile to the <i>Eaat1</i> gene, an astrocyte marker, in every individual cell inside the <i>Drosophila</i> optic lobe and midbrain, as well as in the entire <i>Drosophila</i> brain throughout its development. Consistent with our bioinformatics data, immunostaining of the brains dissected from transgenic adult flies showed co-expression of <i>CG11000</i> with <i>Eaat1</i> in a set of single cells corresponding to the astrocytes in the <i>Drosophila</i> brain. Physiologically, inhibiting <i>CG11000</i> through RNA interference disrupted the normal development of male <i>D. melanogaster</i>, while having no impact on females. Expression suppression of <i>CG11000</i> in adult flies led to decreased locomotion activity and also shortened lifespan specifically in astrocytes, indicating the gene’s significance in astrocytes. We designated this gene as ‘<i>deathstar</i>’ due to its crucial role in maintaining the star-like shape of glial cells, astrocytes, throughout their development into adult stage.