Tubby-RFP balancers for developmental analysis: FM7c 2xTb-RFP, CyO 2xTb-RFP, and TM3 2xTb-RFP.

We report here the construction of Tubby-RFP balancers for the X, 2nd and 3rd chromosomes of Drosophila melanogaster. The insertion of a 2xTb-RFP transgene on the FM7c, CyO, and TM3 balancer chromosomes introduces two easily scorable, dominant, developmental markers. The strong Tb phenotype is visible to the naked eye at the larval L2, L3, and pupal stages. The RFP associated with the cuticle is easily detected at all stages from late embryo to adult with the use of a fluorescence stereomicroscope. The FM7c Bar 2xTb-RFP, CyO Cy 2xTb-RFP, and TM3 Sb 2xTb-RFP balancers will greatly facilitate the analysis of lethals and other developmental mutants in L2/L3 larvae and pupae, but also provide coverage of other stages beginning in late embryogenesis through to the adult.