Air Sacs/growth & development; DNA-Binding Proteins/metabolism; Drosophila Proteins/metabolism; Drosophila melanogaster/growth & development; Fibroblast Growth Factors/metabolism; Nerve Tissue Proteins/metabolism; Neuregulins/metabolism; Proto-Oncogene Proteins/metabolism; Transcription Factors/metabolism; Air Sacs/cytology; Air Sacs/metabolism; Animals; Animals, Genetically Modified; DNA-Binding Proteins/genetics; Drosophila Proteins/genetics; Drosophila melanogaster/genetics; ErbB Receptors/genetics; ErbB Receptors/metabolism; Female; Fibroblast Growth Factors/genetics; Gene Expression Regulation, Developmental; Larva; Male; Nerve Tissue Proteins/genetics; Neuregulins/genetics; Protein-Tyrosine Kinases/genetics; Protein-Tyrosine Kinases/metabolism; Proto-Oncogene Proteins/genetics; Receptors, Fibroblast Growth Factor/genetics; Receptors, Fibroblast Growth Factor/metabolism; Receptors, Invertebrate Peptide/genetics; Receptors, Invertebrate Peptide/metabolism; Signal Transduction/genetics; Transcription Factors/genetics