at University of Buffalo have developed an innovative method for
studying the function of certain genes even in the absence of the
genome sequencing in "non-model" organisms.
The researchers used lasers to turn on fluorescent marker genes in very
precise pattern but otherwise the butterflies were unaffected.
Exploring functional genetics in "model" organisms - like the fruit fly
or the mouse - is much easier, as the amount of research made on them
provides highly sophisticated and efficient tools.
Discovering how genes work in other organisms is particularly difficult
as the regulatory code of such organisms is still poorly understood.
“With this research, we have developed a tool to test gene function in
an animal where these kinds of tools were not available before,”
said Diane Ramos, a doctoral candidate in the UB Department of
Biological Sciences in the College of Arts and Sciences. “We hope to
inspire other researchers working in non-model organisms to use these
kinds of techniques to answer fundamental questions about what genes
do, which will allow interesting comparisons between species.”
The method consists in introducing a heat-sensitive fragment of
regulatory DNA into the genome of butterflies, along with the genes
aimed to be activated at precise loci and times during wing
development. "As the laser heats up specific cells on the butterfly
wing, genes that sit next to this regulatory sequence get turned on,
allowing for specific clusters of cells on the wing to fluoresce," said
Antonia Monteiro, assistant professor of ecology and evolutionary
biology at Yale University.
The team wants to apply the method to the genes involved in encoding
the intricate patterns on butterfly wings. "We want to be able to turn
on or shut down specific genes on the developing butterfly wing in
order to test their function in coloring the wing," said Monteiro. This
method could be applied to assessing color patterns of other insects,
fish, birds or plants. "Now they may be able to attempt to use a laser
beam to direct gene expression to particular clusters of cells," she
The method was first used in a transgenic strain of the butterfly
species Bicyclus anynana (photo) containing the GFP reporter gene, a
common jellyfish marker gene, attached to a Drosophila heat shock
promoter, which reacted similarly to heat in butterflies.