Detection of genetically modified maize and soybean in feed samples

Area of Science:

• Agricultural Biotechnology
• Food Safety
• Molecular Biology

Background:

• Genetically modified (GM) crops are increasingly prevalent in food and feed products.
• Regulatory control of GM crop production and labeling is crucial for environmental and human health.
• Long-term impacts of GM consumption necessitate robust detection methods.

Purpose of the Study:

• To genetically analyze 11 feed samples from Turkey for the presence of foreign genes.
• To determine if the feed samples contain specific genetically modified traits, such as insect resistance or herbicide tolerance.

Main Methods:

• Conventional Polymerase Chain Reaction (PCR) was used to screen for cauliflower mosaic virus 35S promoter (CaMV35S) and nopaline synthase terminator (T-NOS) sequences.
• Nested PCR and conventional PCR were employed to detect specific GM events: Bt176 in maize and GTS-40-3-2 in soy.
• Analysis utilized primers specific to the Bt176 insect-resistant cryIAb gene and the herbicide resistance CTP4-EPSPS construct.

Main Results:

• All 11 feed samples tested positive for the presence of transgenic elements (CaMV35S and T-NOS promoters).
• None of the samples tested positive for the Bt176 event (insect resistance).
• All samples were confirmed positive for the GTS-40-3-2 transgenic soy variety, indicating the presence of herbicide resistance.

Conclusions:

• The study confirms the presence of genetically modified soy (GTS-40-3-2) in all analyzed feed samples from Turkey.
• While insect-resistant genes (Bt176) were not detected, the widespread presence of herbicide-resistant soy highlights the need for continued monitoring.
• These findings underscore the importance of accurate detection methods for GM ingredients in animal feed.