“…The latter is often referred to as auto-excision. In the first subcategory, the recombinase can be delivered to a transgenic plant by retransformation (Odell et al, 1990;Dale and Ow, 1991;Lyznik et al, 1996), by sexual crosses (Bayley et al, 1992;Russell et al, 1992;Kilby et al, 1995;Kerbach et al, 2005), or by transiently expressing the recombinase (Gleave et al, 1999;Kopertekh et al, 2004aKopertekh et al, , 2004bKopertekh and Schliemann, 2005;Jia et al, 2006). Recently, the company Renessen received U.S. regulatory approval (http://www.aphis.usda.gov/ brs/aphisdocs2 /04_22901p_com.pdf) for the transgenic line LY038 from which the selectable marker, originally present between tandemly oriented lox sites, was removed through introduction of the cre gene by a sexual cross (Ow, 2007).…”