Transcription profiling by array of Atlantic salmon fed genetically modified Bt-maize or non-modified parental maize
ID:
状态:
发布时间Oct. 1, 2010
, 更新时间 May 2, 2014
, 提交时间 Aug. 3, 2010,
物种:
Salmo salar
摘要:
This study was conducted to follow up on apparent differences in growth, relative organ sizes, cellular stress and immune function in Atlantic salmon fed genetically modified (GM) Bt-maize compared to the non-modified parental maize line. Gene expression profiling on the distal intestinal segment and liver were performed by the cGRASP 16K salmonid cDNA microarray. Analysis of the intestinal microarray data revealed nearly 500 differentially regulated genes with a false discovery rate of zero, despite modest fold differences (average 2.4 for the down-regulated and 1.7 for the up-regulated genes). However, nine out of ten genes were found not to be significantly different when followed up by quantitative polymerase chain reaction (qPCR), but direction and magnitude of the change was generally confirmed, at least for the up-regulated genes. For the liver microarray data, statistical analyses could not be performed due to constraints in the design. qPCR revealed some differentially regulated genes in the liver, including up-regulation of gelsolin precursor, down-regulation of ferritin heavy subunit and a tendency towards down-regulation of metallothionein B. This, combined with up-regulation of anti-apoptotic protein NR13 and a tendency towards up-regulation of both ferritin heavy chain and metallothionein A and B in the distal intestine, suggests changes in cellular stress/ anti-oxidant status. This corresponds well with, and strengthens previous findings in these fish. To exclude possible confounding factors, the maize ingredients were analyzed for mycotoxins and metabolites, and the GM maize variety contain 90μg/kg deoxynivalenol (DON), compared to levels below the detection limit in the non-GM maize. Numerous differences were also seen in the metabolite profiles of the two maize varieties, some of which seem to be connected to the mycotoxin level. The effects on salmon observed in the current and in previous studies correspond relatively well with effects of DON as reported in the literature for other production animals, but knowledge regarding effects and harmful dose levels in fish are practically non-existing, thus it is difficult to conclude whether the observed effects in the fish are caused by the DON level or by some other aspect of the GM maize ingredient.