title: Bioluminescence imaging to track real-time armadillo promoter activity in live Drosophila embryos.
abstract: We established a method for bioluminescence imaging (BLI) to track real-time gene expression in live Drosophila embryos. We constructed a transgenesis vector containing multiple cloning sites and enhanced green-emitting luciferase (ELuc; Emerald Luc), a brighter and pH-insensitive luciferase for promoter analysis. To evaluate the utility of BLI using an ELuc reporter together with an optimized microscope system, we visualized the expression pattern of armadillo (arm), a member of the Wnt pathway in Drosophila, throughout embryogenesis. We generated transgenic flies carrying the arm:: ELuc fusion gene, and successfully performed BLI continuously for 22 h in the same embryos. Our study showed, for the first time, that arm::Eluc expression was dramatically increased in the anterior midgut rudiment, myoblasts of the dorsal/lateral musculature, and the posterior spiracle after stage 13, and the cephalic region at stage 17. To further demonstrate the application of our BLI system, we revealed that arm transcriptional activity in embryos was modulated inversely by treatment with ionomycin or 6-bromoindirubin-3-oxime (BIO), an inhibitor and activator of Wnt/β-catenin signaling, respectively. Therefore, our microscopic BLI system is useful for monitoring gene expression in live Drosophila embryos, and for investigating regulatory mechanisms by using chemicals and mutations that might affect expression.
authors.affiliation: Corporate Research and Development Center, Olympus Corporation, Kuboyama 2-3, Hachioji, Tokyo, 192-8512, Japan, ryutaro_akiyoshi@ot.olympus.co.jp.
authors.forename: Ryutaro
authors.initials: R
authors.lastname: Akiyoshi
authors.forename: Taro
authors.initials: T
authors.lastname: Kaneuch
authors.forename: Toshiro
authors.initials: T
authors.lastname: Aigaki
authors.forename: Hirobumi
authors.initials: H
authors.lastname: Suzuki
mesh_terms: D000818:Animals; D051186:Armadillo Domain Proteins / Q000235:genetics* / Q000378:metabolism; D004330:Drosophila / Q000737:chemistry* / Q000196:embryology* / Q000235:genetics / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics* / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D008163:Luminescent Measurements / Q000379:methods*; D057054:Molecular Imaging / Q000379:methods*; D010063:Ovum / Q000737:chemistry / Q000378:metabolism; D011401:Promoter Regions, Genetic; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism
chemical_list: C495305:ARM protein, Drosophila; D051186:Armadillo Domain Proteins; D029721:Drosophila Proteins; D014157:Transcription Factors