Guarding Zebrafish Embryo by Shell Engineering

May 18, 2010

Experiments on zebrafish embryo development in simulated ozone hole situation are under way in chemical labs of Zijingang campus. In contrastive experiments, the bare zebrafish embryos exposed to ultraviolet radiation stopped development and died, while zebrafish embryos coated with protective shield were thriving and successfully completed all development processes.

The research team headed by Professor Tang Ruikang, Cheung Kong Scholar in Department of Chemistry, has worked out a strategy to shield lives to counteract ozone depletion. The related paper Guarding Embryo Development of Zebrafish by Shell Engineering: A Strategy to Shield Life from Ozone Depletion was published in PLoS ONE.

As is known to all, the reduced concentration of stratospheric ozone results in increased ultraviolet radiation reaching earth surfaces which poses a great threat to the reproduction of living species on earth. Vulnerable to ultraviolet radiation, fertilized eggs of fish are likely to suffer DNA damage. Scientists have found that the ozone hole over Antarctica has caused the sharp decline in the number of regional fish.

Mother Nature brings a wealth of inspiration. There is a kind of marine alga having a covering of plates against UV light. Natural biological structures are providing inspiration for the Tang Ruikang team to seek for technological strategy. The team has been engaged in biomineralization research. In 2008, they succeeded in prolonging the life of yeast by coating them with artificial clothing. Based on the same principle, the team is working on the strategy to provide cells with a coating against UV light.

(Parallel development stages of the bare embryo and the coated embryo under UV radiation)

Zebrafish are frequently used in scientific experiments. After more than a year s research, the team developed bio-compatible plate for zebrafish based on rare earth phosphate. This material is also an important energy-saving powder which absorbs UV light and converts it to green fluorescence. The researchers placed zebrafish eggs to the solution with rare earth ingredients for 20 minutes for the formation of the shell on the surface of the eggs. The key to this experiment is to reduce or eliminate the adverse effect of artificial materials on the cells, Prof. Tang introduced.

Experiments show that the artificial mineral-shell reduces the UV radiation effectively and the enclosed embryos become more robust. Under the protection of the shell, eggs can develop normally and there is no distortion of the juvenile form. Prof. Tang comments that these experiments suggest an engineered shell of functional materials onto biological units can be developed as a strategy to shield lives to counteract negative changes of global environment.