Transcriptional regulation of abd-A and Abd-B in Drosophila larval adipocytes [CUT&Run]

We previously showed that heterogeneous expression of the BX-C genes abd-A and Abd-B defines regional differences between thoracic and abdominal adipocytes. However, the mechanisms underlying this heterogeneity in adipocytes remain unclear.

Here, we identify cis-regulatory regions and transcription factors that control abd-A and Abd-B expression specifically in abdominal, but not thoracic, adipocytes of the larval fat body. Using a promoter bashing approach, we identified a 627-bp fragment within the Abd-B locus and a ~6-kb region within the abd-A locus that are sufficient to drive heterogeneous expression in larval adipocytes. Yeast one-hybrid screening combined with functional analysis identified the transcription factors Lola (Longitudinals lacking), Lolal (Lola like), and Combgap/Cg as key regulators of Abd-B expression, with Prg Piragua/Prg and Svp (Seven up) acting as transcriptional activators.