GHB614 × T304-40 × GHB119 × COT102 Cotton: Protein Expression Analyses of Field-Grown Samples.

Food and feed safety assessment is not enhanced by performing protein expression analysis on stacked trait products. The expression levels of six proteins in cotton matrices from four single cotton events and three conventionally stacked trait cotton products are reported. Three proteins were for insect control; two proteins confer herbicide tolerance; and one protein was a transformation-selectable marker. The cotton matrices were produced at three U.S., five Brazil, and two Argentina field trials. Similar protein expression was observed for all six proteins in the stacked trait products and the single events. However, when two copies of the bar gene were present in the stacked trait products, the expression level of phosphinothricin acetyl transferase herbicide tolerance was additive. Conventional breeding of genetically engineered traits does not alter the level or pattern of expression of the newly introduced proteins, except when multiple copies of the same transgene are present.

Plants with genetically modified events combined by conventional breeding: an assessment of the need for additional regulatory data.

Crop varieties with multiple GM events combined by conventional breeding have become important in global agriculture. The regulatory requirements in different countries for such products vary considerably, placing an additional burden on regulatory agencies in countries where the submission of additional data is required and delaying the introduction of innovative products to meet agricultural needs. The process of conventional plant breeding has predictably provided safe food and feed products both historically and in the modern era of plant breeding. Thus, previously approved GM events that have been combined by conventional plant breeding and contain GM traits that are not likely to interact in a manner affecting safety should be considered to be as safe as their conventional counterparts. Such combined GM event crop varieties should require little, if any, additional regulatory data to meet regulatory requirements.

Performance of lactating dairy cows fed silage and grain from a maize hybrid with the cry1F trait versus its nonbiotech counterpart.

Effects of feeding grain and maize silage from a non-Bt maize and a variety of Bt maize that contains cry1F (event TC1507, event DAS-Ø15Ø7-1), a gene that provides maize with insect resistance, on the health and performance of dairy cows were evaluated. In a crossover trial, 20 lactating Holstein cows were assigned to each of 2 dietary treatment groups and fed diets containing whole-plant maize silage plus maize grain from TC1507 or its near-isoline counterpart (control). Each period of the crossover trial lasted 28 d and was preceded by a 7-d adjustment period. To minimize variability due to stage of lactation, 2 blocks of 10 cows at 90 to 130 d of lactation at the start of the trial were used. Within each dietary treatment, 10 cows were from each of 2 genetic selection lines (high and average fat plus protein predicted transmitting ability). Diets were formulated to be isocaloric and isonitrogenous. Dry matter intake and daily production of milk, fat, protein, lactose, nonfat solids, and total solids did not differ between cows fed the TC1507 diet and cows fed the control diet. Furthermore, milk from cows in different dietary treatment groups did not differ in milk urea nitrogen concentration or somatic cell count. For milk fat percentage, a significant dietary treatment by genetic group interaction was detected although overall yield of milk and solids-corrected milk did not differ with diet. Physical measures of cow health including body weight, body condition score, temperature, pulse, and respiration rate were collected weekly; dietary treatment group means for these measures were not different. Blood chemistry and hematological analyses were conducted using blood samples collected from cows before the start of the trial and at the end of each period. Overall, the TC1507 and control groups did not differ in any of these indices of health status. Further, hematological profiles for cows in the dietary treatment groups were not different. In summary, no differences were detected in milk production, milk composition, or cow health as indicated by physical measures, blood chemistry, and hematological analyses between dairy cows fed diets containing maize grain plus whole-plant maize silage from TC1507 and dairy cows fed grain plus silage from its near-isoline counterpart.

Specificity and efficacy of purified Bacillus thuringiensis proteins against agronomically important insects.

The host range and relative efficacy of three purified Bacillus thuringiensis insect control proteins were determined against 17 different agronomically important insects representing five orders and one species of mite. The three B. thuringiensis proteins were single gene products from B. thuringiensis ssp. kurstaki HD-1 (CryIA(b)) and HD-73 (CryIA(c)), both lepidopteran-specific proteins, and B. thuringiensis ssp. tenebrionis (CryIIIA), a coleopteran-specific protein. Seven insects showed sensitivity to both B. thuringiensis ssp. kurstaki proteins, whereas only 1 of the 18 insects was sensitive to B. thuringiensis ssp. tenebrionis protein. The level of B. thuringiensis ssp. kurstaki protein required for 50% mortality (LC50) varied by 2000-fold for these 7 insects. A larval growth inhibition assay was developed to determine the amount of B. thuringiensis ssp. kurstaki protein required to inhibit larval growth by 50% (EC50). This extremely sensitive assay enabled detection of B. thuringiensis ssp. kurstaki HD-73 levels as low as 1 ng/ml.