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cry1Ab Gene (cry1ab + gene)

Distribution by Scientific Domains
Life Sciences100%

Selected Abstracts

Degradation of transgenic Cry1Ab DNA and protein in Bt-176 maize during the ensiling process

JOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 3-4 2006
B. Lutz
Summary Maize silage is commonly used as feed for farm animals. The aim of this study was to monitor the time-dependent degradation of non-recombinant chloroplast DNA (exemplified by the rubisco gene) in comparison with the recombinant cry1Ab gene in the course of the ensiling process. In parallel, the Cry1Ab protein content and fragment sizes were determined. Fragments of the rubisco (173, 896, 1197, 1753 and 2521 bp) and of the cry1Ab gene (211, 420, 727 and 1423 bp) were selected to investigate the DNA degradation process. The detection of the Cry1Ab protein was performed using an enzyme-linked immunosorbent assay (ELISA) and immunoblotting. Rubisco gene fragments of 173 bp were still detectable after 61 days, while fragments of 1197 and 2521 bp were detectable up to 30 days and on the first day only respectively. Polymerase chain reaction (PCR) analyses revealed that fragments of the cry1Ab gene with sizes of 211 and 420 bp were detectable up to 61 days, fragments with sizes of 727 and 1423 bp, 30 and 6 days respectively. The ELISA showed a decrease of the Cry1Ab protein in maize silage during the ensiling process. No marked degradation was observed during the first 43 h. Thereafter, a sharp decrease was measured. After 61 days, 23.6 ± 0.9% of the initial Cry1Ab protein was still detectable. Immunoblotting confirmed the results of the ELISA showing a positive signal of approximately 60 kDa size for 8 days of ensiling; no further immunoactive fragments were detectable by immunoblotting. In conclusion, the ensiling process markedly decreases the presence of long functional cry1Ab gene fragments and full size Cry1Ab protein. [source]

Field studies on the environmental fate of the Cry1Ab Bt-toxin produced by transgenic maize (MON810) and its effect on bacterial communities in the maize rhizosphere

MOLECULAR ECOLOGY, Issue 8 2005
SUSANNE BAUMGARTE
Abstract Field studies were done to assess how much of the transgenic, insecticidal protein, Cry1Ab, encoded by a truncated cry1Ab gene from Bacillus thuringiensis (Bt), was released from Bt-maize MON810 into soil and whether bacterial communities inhabiting the rhizosphere of MON810 maize were different from those of the rhizosphere of nontransgenic maize cultivars. Bacterial community structure was investigated by SSCP (single-strand conformation polymorphism) of PCR-amplified 16S rRNA genes from community DNA. Using an improved extraction and detection protocol based on a commercially available ELISA, it was possible to detect Cry1Ab protein extracted from soils to a threshold concentration of 0.07 ng/g soil. From 100 ng of purified Cry1Ab protein added per gram of soil, only an average of 37% was extractable. At both field sites investigated, the amount of Cry1Ab protein in bulk soil of MON810 field plots was always lower than in the rhizosphere, the latter ranging from 0.1 to 10 ng/g soil. Immunoreactive Cry1Ab protein was also detected at 0.21 ng/g bulk soil 7 months after harvesting, i.e. in April of the following year. At this time, however, higher values were found in residues of leaves (21 ng/g) and of roots (183 ng/g), the latter corresponding to 12% of the Cry1Ab protein present in intact roots. A sampling 2 months later indicated further degradation of the protein. Despite the detection of Cry1Ab protein in the rhizosphere of MON810 maize, the bacterial community structure was less affected by the Cry1Ab protein than by other environmental factors, i.e. the age of the plants or field heterogeneities. The persistence of Cry1Ab protein emphasizes the importance of considering post-harvest effects on nontarget organisms. [source]

Quality variations in transgenic rice with a synthetic cry1Ab gene from Bacillus thuringiensis

PLANT BREEDING, Issue 3 2002
D. X. Wu
Abstract In order to estimate the potential of transgenic rice, characteristics related to grain quality and starch viscosity were investigated in six japonica lines based on three primary transgenic lines containing a synthetic cry1Ab gene from Bacillus thuringiensis. No significant differences were found between the transgenic lines and the wild type, including negative lines and an untransformed line. All six transgenic lines were comparable in size, milling quality, appearance quality and physicochemical properties to the wild type that were derived from. One exception was that the lines derived from the primary transgenic line TR0-101 had smaller grains. Crude protein contents were equivalent in all the material tested, but Cry1Ab protein was only detected in grains of transgenic rice and was undetectable in the cooked rice. The viscosity of the starch differed between the transgenic lines, the wild type and other controls, and two transgenic lines had breakdown values (BDV) and setback values (SBV) similar to the wild type. A positional effect of T-DNA insertion on starch viscosity was found in three primary transgenic lines. [source]