No abstract

Genetically modified corn has been approved as an animal feed in several countries, but information about the fate of genetically modified DNA and protein in vivo is insufficient. Genetically modified corn Bt11 is developed by inserting a recombinant DNA sequence encoding insecticidal Cry1Ab protein from Bacillus thuringiensis subsp. kurstaki. We examined the presence of corn intrinsic and recombinant cry1Ab gene by PCR, and the Cry1Ab protein by immunological tests in the gastrointestinal contents of five genetically modified corn Bt11-fed and five nongenetically modified corn-fed pigs. Fragments of corn zein (242 bp), invertase (226 bp) and of ribulose-1,5-bisphosphate carboxylase/ oxygenase genes (1,028 bp) were detected in the gastrointestinal contents of both Bt11 and nongenetically modified corn-fed pigs. Fragments of recombinant cry1Ab gene (110 bp and 437 bp) were detected in the gastrointestinal contents of the Bt11-fed pigs but not in the control pigs. Neither corn intrinsic nor cry1Ab gene fragments were detected in the peripheral blood by PCR. The gastrointestinal contents were positive for Cry1Ab protein by ELISA, immunochromatography, and immunoblot; however, these methods did not work for blood and precluded conclusions about any potential absorption of the protein. These results suggest that ingested corn DNA and Cry1Ab protein were not totally degraded in the gastrointestinal tract, as shown by their presence in a form detectable by PCR or immunological tests.

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Golden jackals are locally common in Bangladesh despite intensive cultivation and high human densities. We studied the relative importance of seasonal flooding, rodent prey-base, and daytime cover on the occurrence of golden jackals in the two major agro-ecosystems in Bangladesh, one with annual monsoon flooding and the other without. Jackals were less common throughout the year where floodwaters occurred that would have excluded them for 1-3 months during their pup-rearing season. Diets of jackals were similar in the two agro-ecosystems. Rodents were the most common food type in scats throughout the year. The occurrence of burrowing rats in scats peaked seasonally when these rats were most concentrated in ripening cereals, suggesting that jackals are beneficial for rat control. Radiotelemetry of seven jackals in the non-flooded agro-ecosystem over an 11-month period indicated that sugarcane was the preferred type of daytime cover, despite representing only 2-4% of the area. There was a day-to-day return rate of 67% to the same 1-ha patch of cover. Evidently, sugarcane provides daytime cover for avoiding humans and for feeding on roof rats (Rattus rattus), which concentrate in this crop. Evidence suggests that breeding pairs of jackals were annual residents that defended cover (average of 37.3 ha) but not foraging areas beyond.

No abstract