Many kinds of genetically modified (GM) crops, which include GM soy, maize, rapeseed, cotton and potato, have already been developed and the cultivated acreage of these crops has continued to grow year by year. It was reported that the global area of GM crops for 2003 was 67.7 million hectares with a growth rate of 15% compared to that in 2002. This growth is estimated to rapidly increase, since the planting has been spread all over the world in addition to the nations such as United States (U.S.) and Canada. 1) On the other hand, public concern has been raised in terms of food safety and environmental effects of the GM crops. Especially, consumers are concerned about the negative effects of GM food on their health by their consumption and scientific information has been strongly required.2) Therefore, many governments have now been considering regulations for the use and implementing a labeling system for GM crops as food and feed. Thus, new labeling systems have been introduced for GM foods in the European Union (EU), Australia, Korea, Japan and other countries.The commercialization of fifty-five lines of safety-assessed GM crops including soy, maize, potato, rapeseed, cotton and sugar beet, have already been approved by the Ministry of Health, Labour and Welfare (HMLW) in Japan. To monitor the labeling system, it is necessary to develop reliable and practical methods for the detection and identification of GM crops. The polymerase chain reaction (PCR) is one of the widely used systems for the quantitative or qualitative detection of GM crops and we also have previously reported PCR methods for the detection of GM soy, maize, papaya and potatoes.
3-10)The tetraploid cultivated potato (Solanum tuberosum) is one of the world's four major crops and an important feedstuff, but it is easily infected by many kinds of pests and pathogens.11) Therefore, molecular biology techniques has been attempted to improve the potato varieties which ended with the breeding of GM potatoes commercialized by the Monsanto Co. We have developed polymerase chain reaction (PCR) methods for the qualitative detection of the GM potatoes for the screening and the identification of NL, NLP and NLY. The gene encoding uridine diphosphate (UDP)-glucose pyrophosphorylase (UGPase) was used as a taxon specific gene. We designed the primer pair to detect the cryIIIA genes as a screening method for GM potatoes because the gene should be inserted in all 8 lines of the GM potatoes. For identification of NL, NLP and NLY, we further designed three specific primer pairs for the different recombinant DNAs (r-DNA) specifically introduced into NL, NLP, or NLY. In addition, to identify the 3 lines of NLY that have been introduced with the same r-DNA, the three line-specific primer pairs for the border sequence between the r-DNA and genomic DNA of NLY 3 lines were designed. Six lines of GM potato used as the test material were specifically identified using the each primer pair under the same PCR condition. The detection limits of all the GM potatoes should b...
