Fine Structural Changes in the Ileum of Mice Fed on δ‐Endotoxin‐Treated Potatoes and Transgenic Potatoes

Abstract

The present work has been designed to study the effect of feeding on transgenic potatoes, which carry the CryI gene of Bacillus thuringiensis var. kurstaki strain HD1, on the light and electron microscopic structure of the mice ileum, in comparison with feeding on potatoes treated with the 'delta-endotoxin' isolated from the same bacterial strain. The microscopic architecture of the enterocytes of the ileum of both groups of mice revealed certain common features such as the appearance of mitochondria with signs of degeneration and disrupted short microvilli at the luminal surface. However, in the group of mice fed on the 'delta-endotoxin', several villi appeared with an abnormally large number of enterocytes (151.8 in control group versus 197 and 155.8 in endotoxin and transgenic-treated groups, respectively). Fifty percent of these cells were hypertrophied and multinucleated. The mean area of enterocyte was significantly increased (105.3 microm(2) in control group versus 165.4 microm(2) and 116.5 microm(2) in endotoxin and transgenic-treated groups, respectively). Several forms of secondary lysosomes or auotophagic vacuoles were recognized in these cells. These changes were confirmed with the scanning electron microscope which revealed a remarkable increase in the topographic contour of enterocytes (23 microm in control group versus 44 microm and 28 microm in endotoxin and transgenic-treated groups, respectively) at the divulged surface of the villi. The basal lamina along the base of the enterocytes was damaged at several foci. Several disrupted microvilli appeared in association with variable-shaped cytoplasmic fragments. Some of these fragments contained endoplasmic reticulum, as well as ring-shaped annulate lamellae. In addition, the Paneth cells were highly activated and contained a large number of secretory granules. These changes may suggest that delta-endotoxin-treated potatoes resulted in the development of hyperplastic cells in the mice ileum. Although mild changes are reported in the structural configuration of the ileum of mice fed on transgenic potatoes, nevertheless, thorough tests of these new types of genetically engineered crops must be made to avoid the risks before marketing.

In Vivo Studies on Possible Health Consequences of Genetically Modified Food and Feed—with Particular Regard to Ingredients Consisting of Genetically Modified Plant Materials

“…In none of these studies were effects related to GM-materials reported. On the other hand, adverse effects were reported (but not explained) in independent studies by Pusztai (1998Pusztai ( , 2002, Fares and El-Sayed (1998), Ewen and Pusztai (1999) and Pusztai et al, (1999). It is remarkable that these effects have all been observed after feeding for only 10-14 days.…”

Toxicity Studies of Genetically Modified Plants: A Review of the Published Literature

“…The gene was transmitted into the plant cells via a shuttle plasmid vector after cloning in E. Coli. Fares and El-Sayed (1998) investigated the effect of feeding transgenic potatoes, which carry the CryI gene of Bacillus thuringiensis var. kurstaki strain HD1, on the light and electron microscopic structure of the mice ileum, in comparison with feeding potatoes treated with the "delta-endotoxin" isolated from the same bacterial strain.…”

Physiological and Biochemical Significance of Genetically Modified Foods: An Overview

“…Out of twenty female rats fed the GM tomato, seven were reported to develop stomach lesions [77]. The form of stomach lesions associated to tomatoes could lead to life-threatening hemorrhage, predominantly in the elderly who use aspirin to preclude blood clots [78]. Further, mice fed potatoes engineered to produce the Bt-toxin developed atypical and damaged cells, as well as proliferative cell growth in the lower part of their small intestine [79].…”