Retinas were dissected from 3-7 days-post-eclosion adult female Drosophila using fine forceps and microdissection scissors. Each sample consists of 40 retinas pooled from 20 individuals. Total RNA was isolated using the PureLink RNA purification kit (Invitrogen, 12183020) according to the manufacturer's instructions along with on-column PureLink DNase treatment (Invitrogen, 12185010). Library construction was performed by the Genomic Sequencing and Analysis Facility at UT Austin, Center for Biomedical Research Support (RRID# SCR_021713) using the 3 Tag-Seq protocol.