“Transgenic tools for manipulation of gene expression are invaluable for labeling and tracking cell populations and for assessing genetic and cellular functions in developmental, physiological and behavioral studies.” (Subedi et al. 2014)
The Gal4/UAS system is the most widely used binary transcription system from yeast, and nowhere is its power and versatility better illustrated than in Drosophila melanogaster.
As transgenic systems become available for other organisms the establishment of effective binary systems becomes a priority for the reasons Subedi et al (2104) articulate above. In the zebra fish, Danio rerio, the Gal4/UAS system is not particularly effective because of rapid methylation of sequences in the Gal4 UAS, resulting in it becoming unresponsive to Gal4, sometimes within just a generation after integration.
An alternative system was needed by zebrafish researchers. Fortunately just such a system, called the Q system, was developed in Drosophila not long ago (Potter et al 2014) and the developer of that system (and IGTRCN Participant), Chris Potter, is a coauthor of the manuscript by Subedi et al. 2014.
Neurospora has a cluster of genes involved in quinic acid metablolism, allowing it to be used as a carbon source in glucose-limited conditions.
The gene cluster is regulated by a transcription factor QF and genes regulated by QF have upstream activating sequences where QF binds (QUAS). In addition, the protein QS prevents QF-mediated expression by binding to QF. So QF/QS/QUAS this is very much analogous to Gal4/Gal80/UAS.
Subedi et al. 2014 describe their successful deployment of QF/QS/QUAS in zebra fish and present evidence that strongly suggests that it will not be subject to the same sort of silencing seen with use of the Gal4/UAS system.
While this recent publication of Subedi et al (2014) is instructive and relevant for insect biologists interested in Genetic Technologies, more relevant to IGTRCN Participants and worth reading is Potter et al (2010) where the Q system is described for use in Drosophila melanogaster. While binary transcription systems have not been used extensively outside of D. melanogaster they are beginning to emerge as viable tools and the Q system increases the options available to insect biologists. Both papers are worth close reading.
Adoption of the Q transcriptional regulatory system for zebrafish transgenesis. 2014 Abhignya Subedi, Michelle Macurak, Stephen T. Gee, Estela Monge, Mary G. Goll, Christopher J. Potter, Michael J. Parsons, Marnie E. Halpern Methods 66 433–440 DOI: 10.1016/j.ymeth.2013.06.012
The Q System: A Repressible Binary System for Transgene Expression, Lineage Tracing, and Mosaic Analysis. 2014 Christopher J. Potter, Bosiljka Tasic , Emilie V. Russler , Liang Liang ,Liqun Luo Cell Volume 141, Issue 3, p536–548 DOI: http://dx.doi.org/10.1016/j.cell.2010.02.025
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