There are plenty of tools available to researchers studying gene function in Drosophila or C. elegans, but what about non-model organisms?
Researchers at the University at Buffalo may have leveled the playing field with a method using a laser beam to directly test gene function without specific sequencing information. "It's a way of warming up a select group of cells in a developing organism to provide a very targeted heat shock to specific groups of cells and thereby turning on gene expression in a very controlled spatial fashion," says Antonia Monteiro, who led the team at Buffalo before relocating to Yale late last year.
The researchers tested the method using a green laser on a transgenic line of butterflies that contained a green fluorescent protein gene from a jellyfish. They demonstrated the accuracy of their laser induction method by stenciling the outline of a butterfly on the surface of the butterfly's wing.
Researchers working with model organisms have been able to do single cell heat shock with confocal laser microscopy for quite some time. And that's fine for cell biologists, says Monteiro, but if you're looking at large cellular patterns, laser microscopes aren't much help.
"This laser is much more flexible because it's a large beam of energy, unlike laser beams that come through the lenses of microscopes," says Monteiro. "Using a plain laser with a large beam gives researchers more flexibility in being able to turn on gene expression in much larger patches of cells [and] actually see a reasonable effect on the adult phenotype."
Monteiro is currently developing an infrared laser for the same application. Relative to green light, infrared lasers have a larger wavelength, which she believes may afford researchers more time to study the cells without damaging them. The hope is that infrared lasers will act more like standard heat shocking methods, which involve placing the cells in a warm bath or oven. "I think that infrared radiation kind of mimics the type of sheer heat that you get with traditional heat shocking," she says. "In a way, it's mimicking much more closely those sort of previous experiments on heat shock and does not have the potential ionizing effect that a higher-frequency wavelength, like the one we [initially tested], could have on damaging or ionizing molecules inside cells."