Characterization of developmental expression pattern and identification of associated genes in Gal4 enhancer traps. Christopher R Dunne, Devin T Gordon-Hamm, Elizabeth C Marin. Biology, Bucknell University, Lewisburg, PA.

   The mushroom body (MB) of Drosophila melanogaster is an important brain structure for associative learning and memory and in the adult contains five distinct lobes composed of three different kinds of neurons: , '/' and /. In order to effectively study and analyze MB function and development one must be able to specifically label and genetically manipulate each of these neuronal subtypes throughout development. The Gal4/UAS system is commonly used for this purpose; however, it is important to first ensure a stable and specific expression pattern of the Gal4 enhancer trap.
    With this in mind, our lab analyzed the developmental expression pattern of several Gal4 enhancer traps previously reported to be expressed in specific MB neuronal subtypes in the adult brain. We found that none of these lines had stable and specific expression in only one neuronal subtype throughout development. Unexpectedly, we found that the expression pattern of MB247-GAL4 did not include all MB neurons in the adult brain as previously reported. In addition to acquiring expression pattern data, we also determined the genomic location of the Gal4 insert through inverse PCR, thereby identifying flanking genes with a likely role in MB development.