Following the Glow: Researchers Use 'Fluorescent Fish' to Study Gene Function
(麻豆淫院Org.com) -- Researchers at North Carolina State University are using fluorescent fish as a molecular 'beacon' to study the early stages of animal development. The researchers focused their attention on a gene - known as Sp2 - that regulates the expression of other genes, and the fluorescent fish they created may also provide hints to the causes of tumor development.
Sp2 is a member of the Sp family of transcription factors - proteins that act as cellular 鈥渟witchboard operators鈥 by turning genes on or off as needed. NC State researchers had noted that the development of skin tumors was correlated with the production of too much Sp2, and others noted similar findings in prostate cancers, but beyond that very little was known about the protein.
Dr. Jonathan Horowitz, associate professor of oncology, and NC State researchers Jianzhen Xie, Haifeng Yin, Teresa Nichols and Dr. Jeffrey Yoder, wondered whether they could use over-production of Sp2 as an early indicator of tumor formation. They inserted a fluorescent marker into zebrafish - attached to the Sp2 gene - allowing them to trace the synthesis of Sp2 throughout the organism. When the zebrafish were viewed under ultraviolet light, the Sp2 marker glowed red where the gene was expressed.
鈥淶ebrafish are good model animals for this research because their embryos develop in a 24-hour period, and they develop externally so you can watch what is happening under a microscope,鈥 Horowitz says. 鈥淎dditionally, their Sp2 protein is the same as those found in mammals, so the function of the protein will be the same in humans as in zebrafish.鈥
According to Horowitz, earlier findings had suggested that Sp2 regulated development - not just of tumors, but of the organism as a whole. When the team looked at the zebrafish, they quickly saw just how critical Sp2 was to embryonic development.
鈥淲e noticed that in the adult zebrafish that carried the fluorescent marker, the 鈥榣ights were out鈥 except in the ovaries of the females, which glowed bright red,鈥 Horowitz says. 鈥淭hen when the female laid her eggs, they also glowed red. This told us that Sp2 must be important for the earliest stages of development. Sure enough, if we eliminated Sp2 in an embryo, the embryo simply didn鈥檛 develop. We think that we鈥檝e uncovered a fundamental mechanism for embryonic development.鈥
The team鈥檚 findings will appear in the Feb. 3 issue of the Journal of Biological Chemistry.
Horowitz believes that the fluorescent fish will help him answer another question about Sp2: whether the protein plays a role in the development of certain types of cancer.
鈥淚f Sp2 is important in the development of brain cancer, for example, and you鈥檙e using our fluorescent zebrafish to study brain tumors, then theoretically as the tumor grows you should see a bright red brain when you look at those fish under ultraviolet light,鈥 Horowitz says. 鈥淲e think that these fish may be a useful tool - an aquatic canary in the coal mine - that will allow us to detect early tumor development.鈥
More information: 鈥淪P2 is a maternally inherited transcription factor required for embryonic development鈥. Authors: Jianzhen Xie, Haifeng Yin, Teresa D. Nichols, Jeffrey A. Yoder and Jonathan M. Horowitz, North Carolina State University. Published: Feb. 3, 2010 in The Journal of Biological Chemistry.
Provided by North Carolina State University