Lack of repeatable differential expression patterns between MON810 and comparable commercial varieties of maize

Abstract

The introduction of genetically modified organisms (GMO) in many countries follows strict regulations to assure that only products that have been safety tested in relation to human health and the environment are marketed. Thus, GMOs must be authorized before use. By complementing more targeted approaches, profiling methods can assess possible unintended effects of transformation. We used microarrays to compare the transcriptome profiles of widely commercialized maize MON810 varieties and their non-GM near-isogenic counterparts. The expression profiles of MON810 seedlings are more similar to those of their corresponding near-isogenic varieties than are the profiles of other lines produced by conventional breeding. However, differential expression of approximately 1.7 and approximately 0.1% of transcripts was identified in two variety pairs (AristisBt/Aristis and PR33P67/PR33P66) that had similar cryIA(b) mRNA levels, demonstrating that commercial varieties of the same event have different similarity levels to their near-isogenic counterparts without the transgene (note that these two pairs also show phenotypic differences). In the tissues, developmental stage and varieties analyzed, we could not identify any gene differentially expressed in all variety-pairs. However, a small set of sequences were differentially expressed in various pairs. Their relation to the transgenesis was not proven, although this is likely to be modulated by the genetic background of each variety.

Transcriptome and metabolome profiling of field-grown transgenic barley lack induced differences but show cultivar-specific variances

“…Metabolome analysis of Bt-maize by NMR also revealed significant differences in free amino acid contents of the parental line; however, other likely-influential factors were not assessed in this study (9). Comparative transcript profiling of different maize cultivars harboring an identical Bt transgene insertion event revealed that the variability between cultivars was much greater than the influence of the transgene (10,11). Independently, comparison of the potato tuber proteome of 21…”

Evaluation of Genetically Engineered Crops Using Transcriptomic, Proteomic, and Metabolomic Profiling Techniques

“…When performing transcriptomic studies using in vitro-or field-grown maize (Zea mays) plants, Coll et al (2008Coll et al ( , 2009 found differential expression for a minority of transcripts between in vitro-grown MON810 (insectresistant of Bt type) and control lines, and most of these differences were not observed in the field. In real agricultural conditions, under two farming practices (conventional and low-nitrogen fertilization), Coll et al (2010a) found differential expression for only 0.14% of the analyzed sequences (approximately one-third of the maize genome).…”

Resistance of Enlist™(AAD-12) Cotton to Glufosinate

“…An alternative with much greater power is to adjust P-values to control the probability that each declared difference is significant (CurranEverett, 2000). This can be accomplished using a False Discovery Rate (FDR) control procedure (Benjamini and Hochberg, 1995), which is a commonly used approach in studies examining transgenic crops (Herman et al, 2007;Coll et al, 2008;Huls et al, 2008;Jacobs Dow AgroSciences LLC et al, 2008;Stein et al, 2009;Herman et al, 2010). Therefore, the P-values from the contrasts were each adjusted using the FDR method to improve discrimination of true differences among treatments from random effects (false positives).…”