Uptake and Organ Distribution of Feed Introduced Plasmid DNA in Growing or Pregnant Rats

Abstract

Fragments of DNA present in food and feed are taken up by the gastrointestinal tract (GIT) of mammals. The extent of uptake varies according to organism, study design and DNA source. This study explores the hypothesis that actively growing, as well as pregnant rats, are more likely to take up DNA from the GIT than mature animals due to the high demand for nutrients for tissue and organ development. Plasmid DNA (pDNA) was added to standard feed for growing, and pregnant rats. The young rats received one pDNA (50 μg) containing meal by gavage. Blood, organ and tissue samples were harvested at 2 h to 3 days post feeding (p.f). The pregnant females were fed pellets containing pDNA (100 μg) daily, starting at day 5 after established pregnancy. Females and foeti were killed at days 7 and 14 of gestation, and pups at the time of weaning. Genomic DNA was analyzed by PCR followed by Southern blot and real-time PCR. A 201 bp target sequence was detected in mesenteric lymph nodes, spleen, liver and pancreas from growing rats 2 h p.f. At 6 h, target DNA was detectable in the kidneys, and at three days p.f. in the liver. Target DNA was not detected in samples from pregnant rats, their foeti or pups. In conclusion, low level of feed introduced DNA could be transiently detected in organs of young, growing rats. However, indications of increased DNA uptake levels in the GIT of growing rats were not found

Detection of genetically modified food in digesta and organs of rats fed transgenic potato

“…Walsh et al (2011) detected transgenic DNA (cry1Ab) and protein only in the GIT digesta and not in the tissues (kidney, liver, muscle, heart or blood) of pigs fed Bt MON810 maize. Grønsberg et al (2011) reported that the low level of plasmid DNA introduced in feed was transiently detected in organs of young, growing rats; however, there was no indication of increased DNA uptake levels in the GIT of growing rats (Grønsberg et al, 2011). Chowdhury et al (2003) detected endogenous gene segments of maize (zein, 242 bp; invertase, 226 bp; rubisco, 1028 bp) in the GIT contents of pigs fed Bt and non-transgenic maize.…”

The Importance of Maize Management on Dung Beetle Communities in Atlantic Forest Fragments

“…Currently, the actions of Bt toxins (extracted from Bacillus thuringiensis ) are subject to more controversy than when Bt plants were first developed [ 19 ]. Transgenic DNA and proteins may pass through mammalian or avian gastrointestinal tracts [ 20 – 22 ], as well as through animals that consume them, where transgenic DNA and proteins circulate in the blood and internal organs [ 23 ]. The propagation effect of a disturbance at the trophic level to other levels of the food chain may also be occurring.…”

An investigation of horizontal transfer of feed introduced DNA to the aerobic microbiota of the gastrointestinal tract of rats

“…Control rats received the same pellets, but without DNA. Previous studies have shown that the feed source is free of DNA and that DNA mixed into the pellet does not degrade or lose its ability to transform bacteria over a 72 h incubation period at RT [ 56 ].…”