Gene tagging in large genome cereals through Ac/Ds transposons

The maize Ac/Ds transposon system is an effective tool for gene identification that has been successfully introduced into various dicot and monocot species. Using this system, single-copy Ds insertion lines (TNPs) were generated in barley to identify, tag, and determine genes and their function. The bias of the Ac/Ds system towards genic regions and its tendency toward localized transpositions facilitates the discovery and tagging of genes linked to the original Ds insertion site.  Recently, we have improved this system threefold through in vitro approaches. Immature barley embryos from barley Ds insertion lines were transfected through Agrobacterium having a binary construct containing the AcTPase and GFP genes. Screening of transformed immature embryos indicated a high frequency (30-35%) activation of the Ds transposon, a rate threefold greater than previous approaches.  Based on these encouraging results in barley, we are anxious to build a similar resource in oat. Oat is an important crop for animal feed and considered as a healthy food for human consumption but the large genome of oat makes many functional and structural genomics approaches tedious. Introduction of Ac/Ds based transposon system into oat could expedite many genomic discoveries in this large genome cereal.