Traditional methods for studying gene function in an organism, such as disabling genes by random mutagenesis, often reveal the earliest functions of a gene and mask later functions. Assessing later gene functions, for example in metabolism, aging or behavior, requires “conditional” mutations – mutations that can be activated at certain times or in specific tissues.
Wenbiao Chen, Ph.D., assistant professor of Molecular Physiology and Biophysics, and colleagues have applied a conditional mutagenesis gene-trapping method called FlEx to zebrafish. The FlEx method involves random insertion of a “cassette” into the genome. Then, molecular “switches” on the cassette are activated to disrupt gene function or rescue gene function – in a time- or tissue-specific way. The researchers demonstrated the utility of the approach by studying the liver-specific functions of a mitochondrial gene (global disruption of the gene is lethal during zebrafish embryogenesis).
The new approach, described in the Sept. 18 Proceedings of the National Academy of Sciences, could be used to generate conditional mutations throughout the zebrafish genome and should be applicable to many organisms.
This research was supported by grants from the National Eye Institute (EY016092) and the National Institute of Diabetes and Digestive and Kidney Diseases (DK088686) of the National Institutes of Health.
