Light Switch Added to Oligomers Improves Precision of Gene-Blocking Studies

Scientists collaborating with a company that synthesizes antisense oligomers have tested a new Ultraviolet (UV) light-activated on-off switch linked to these molecules. Based on initial testing, the enhanced oligomers promise to deliver detailed insights from studies in fields such as developmental biology and neuroscience.

The team described the advancement in a paper published May 1, 2012, in the journal Development. Philip Washbourne, professor of biology at the Institute of Neuroscience of the University of Oregon (Eugene, USA), says the paper is a proof-of-concept on an idea he discussed with scientists at Gene Tools LLC (Philomath, OR, USA), which produces “Morpholino” oligonucleotides, a form of synthetic short-chain antisense (or sense) oligomers used to block gene function by RNA-binding.

Biologists have been using morpholinos in zebrafish and other model organisms to study development, but the molecules remained in the "on" (active) state. Gene Tools introduced a light-sensitive linker, allowing researchers to control the photo-morpholinos temporally and spatially — even leaving one "on" in one cell and "off" in an adjacent cell — with a pinpoint UV laser beam.

University of Oregon researchers in Westbourne’s lab, led by research associate Alexandra Tallafuss, were challenged to give the new molecules a test run in zebrafish. "Now we can turn them on and off," Prof. Washbourne said, "you can insert them and then manipulate them to learn just when a gene is important, and we learned two things right away." Researchers have known that if the "no tail" gene is blocked in development, zebrafish fail to grow tails. With the new photo-cleavable morpholinos, they discovered that the no-tail gene does not need to produce protein for tail formation until about 10 hours, or very late, into an embryo's development. Secondly, the researchers looked at the gene sox10 that is vital in the formation of neural crest cells. "Again, we found that sox10 is not needed as early in development as theorized," Prof. Washbourne said.

"These light-sensitive molecules significantly expand the power and precision of molecular genetic studies in zebra fish," said Robert Riddle, a program director at the National Institute of Neurological Disorders and Stroke (NINDS); "Researchers from many fields will be able to use these tools to explore the function of different genes in embryonic regions, specific cell types, and at precise times in an animal's lifespan."

Related Links:
Institute of Neuroscience, University of Oregon
Gene Tools LLC