Pulsed irradiation improves target selectivity of infrared laser-evoked gene operator for single-cell gene induction in the nematode C. elegans.
Methods for turning on/off gene expression at the experimenter's discretion would be useful for various biological studies. Recently, we reported on a novel microscope system utilizing an infrared laser-evoked gene operator (IR-LEGO) designed for inducing heat shock response efficiently in targeted single cells in living organisms without cell damage, thereby driving expression of a transgene under the control of a heat shock promoter. Although the original IR-LEGO can be successfully used for gene induction, several limitations hinder its wider application. Here, using the nematode Caenorhabditis elegans (C. elegans) as a subject, we have made improvements in IR-LEGO. For better spatial control of heating, a pulsed irradiation method using an optical chopper was introduced. As a result, single cells of C. elegans embryos as early as the 2-cell stage and single neurons in ganglia can be induced to express genes selectively. In addition, the introduction of site-specific recombination systems to IR-LEGO enables the induction of gene expression controlled by constitutive and cell type-specific promoters. The strategies adopted here will be useful for future applications of IR-LEGO to other organisms.
Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Japan.
Motoshi
M
Suzuki
Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Japan.
Naoya
N
Toyoda
Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Japan.
Shin
S
Takagi
D000818:Animals; D030801:Animals, Genetically Modified; D017173:Caenorhabditis elegans; D018869:Heat-Shock Response / Q000235:genetics*; D007259:Infrared Rays; D007834:Lasers; D011401:Promoter Regions, Genetic