Determination of epitope-labeled Hdc gene expression in transgenic flies of Drosophila
Histidine decarboxylase, or HDC, is a protein that catalyzes the synthesis of histamine from histidine. Present in both vertebrates and invertebrates, Hdc functions in both the peripheral and central nervous systems of the fruit fly. Mutations in the Hdc gene cause visual and behavioral abnormalities. Epitope-labeled Hdc transformant flies were created by injecting a newly constructed transgene, containing the promoter of Hdc fused to the eGFP protein (enhanced green fluorescent protein), into fly embryos. This new transgene should serve as a tool in understanding the processes involved in the development of histamine-containing cells in the nervous system as well as allow the identification of histaminergic cells in living tissue, enabling the study of these cells in vivo using biochemical and electrophysiological tools. The work presented generated two transformant fly lines containing the pHdc-eGFP transgene, one line with the transgene on the second chromosome and the other line with the transgene on the third chromosome. An inverse polymerase chain reaction (iPCR) approach was used to characterize the specific genetic location for the transgene in each of the transformant lines obtained. Analysis indicates that the transgene is located in separate and distinct locations in the fly genome, supporting the linkage analysis done earlier. Microscopic analysis of the transformant flies will reveal whether the level of eGFP expression directed by the Hdc promoter region used is sufficient to mimic the known position of histaminergic cells in the Drosophila CNS. Should eGFP not be easily detected in the transformant flies, further experiments such as RT-PCR and GFP immunocytochemistry will be carried out to see whether any GFP expression may be detected in these transformant flies.
Faculty Mentor: Martin Burg, Biomedical Sciences
Page last modified July 14, 2009