Transgenics mechanisms

Plants tolerant to imidazolinones have been produced by both transgenic and non-transgenic mechanisms. However, all of the imidazohnone-tolerant crops currently being sold have been developed by non-transgenic methods. The first imidazolinone-tolerant crop (maize) was introduced in 1992. Subsequently, four additional imidazolinone-tolerant crops (canola, rice, wheat and sunflower) have been commercialized [31]. All of the imidazohnone-tolerant crops are being sold under the CLEARFIELD trade name. 

Little is known of how the biosynthetic metabolon is assembled, what mechanisms control the membrane-specific targeting, and how the conversions to apocarotenoids occur. Yet the current approach to drive import of bacterial or plant genes is to use transit sequences of a stromal protein that may limit the effectiveness of the transgene. In addition, for specific applications of controlling carotenoid composition, we need to better understand the interactions of the various enzymes,... 

Besides this purported action on DAT, amphetamine has also been suggested to act upon the vesicular transporter as well. Pifl et al.87 examined COS cells transfected with cDNA for either DAT or the vesicular transporter, or both. A marked increase in DA release was noted in cells that expressed both DAT and the vesicular transporter when compared to the release from cells that express only DAT or the vesicular transporter. The mechanism of action for amphetamine was further defined with the work of Giros et al.59 In transgenic mice lacking the DAT, amphetamine did not produce hyperlocomotion or release DA. 

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