Jan. 24 (UPI) -- Scientists in Japan have developed a method for manipulating gene expression using only light. Researchers used the technique to create two-headed zebrafish.
Scientists have previously used light to influence gene expression, but the techniques were deemed unsuitable for the augmentation of embryonic development. They couldn't get the timing right, and their efforts required the assistance of gene modification.
A team of researchers at Hokkaido University in Japan focused on influencing the messenger RNA-to-protein translation process, instead of the DNA-to-mRNA conversion process.
Ultraviolet light kickstarted the translation process, causing mRNAs to bind with "initiation factors." Blue light prevented binding and delayed the translation process. The new method solved the problem of timing.
Researchers tested their method on zebrafish embryos. In the lab, scientists injected embryos with fluorescent protein mRNAs, which could be targeted with blue and ultraviolet light.
When the mRNA was hit with ultraviolet light, the mRNA-to-protein translation process yielded fluorescent protein. Blue light failed to produce fluorescent protein.
The delay between irradiation and protein production was measured in minutes. The delay used to be measured in days, making it difficult to alter gene expression in predictable ways.
Researchers used the new method to manipulate the expression of squint, a gene controlling body axis formation in zebrafish. Their efforts produced two-headed zebrafish.
"Our method would be particularly useful to accurately manipulate embryonic development, and reveal the importance of the timing and duration of gene expression in biological events," lead researcher Shinzi Ogasawara, a scientist at Hokkaido's Creative Research Institution, said in a news release. "By applying this technology to higher model organisms such as mice, we hope to help clarify the role each gene plays in the development of animals as well as in various diseases."
Ogasawara and his colleagues described their feat in the journal ACS Chemical Biology.