Influence genetically modified soybeans on postnatal development of the third generation rats

Abstract

Ukraine is one of European and world leaders in soybean cultivation. According to some estimations, 50% of the crops area is used currently for cultivation of the genetically modified varieties. As modified soybean areas are expanding, potential nutritional threats related to this product should be thoroughly assessed.

There are still vivid discussions on possible threats and food safety of GMO. As seen from analysis of hundreds scientific papers dealing with this problem reviewed in "Genetically Engineered Crops: Experiences and Prospects (2016)", there is still no undoubtful evidence of distinct negative effects of GMO or GMO-containing food on human health.

On the other hand, the idea of potential threat of genetically engineered products is also popular and has many supporters stating that these components should be considered as dangerous as long as no indisputable safety evidences are found. Moreover, some primary deviations were found in the viscera morphogenesis as a result of nutrition with GMO components. Chronic intoxications and some diseases have also been reported for next generations of the lab animals.

That is why the discussion of possible food safety of GMO is still open and requires more data and evidences.

This work deals with investigation of possible influence of nutrition with traditional and genetically modified soybeans in ration with content 35% protein on postnatal development in the third generation of rats.

All experiments were carried from the third generation of the Wistar line rats. All rats were divided into three groups: one control and two experimental. All the groups were formed by random selection of the animals with the only account of the body weight. The control group animals were fed according to the standard vivarium ration. The second group animals were fed with the food containing 35 % protein of thermotreated soybeans. The third group animals were fed using the above procedure but with the genetically engineered soybean Roundup Ready, line GTS 40-3-2: 35% protein of their diet consisted of this GM material.

Counted up the amount of living and dead rats, determined the average size of new-born, by sight fixed general physical state, shortchanged survivability, measured body mass of the rat in 2 months.

It has been found that the pregnancy time was unchanged in both experimental groups comparing to the value of the control group. All baby rats were delivered after 21-23 days of pregnancy.

An average offspring number was 7.3 ± 1.8 individuals in the control group; 7.1 ± 1.9 individuals – in the second group and 7.9 ± 1.9 individuals in the third group. No deviations were found in physical development of young rats from all the groups: the auricle opening time was 3-4 days; body hair erupted after 5-6 days; teething time was 9-10 days and eyes opening time was 15-16 days. No visible mutilations were registered.

Death rate for the first five days was 5.2 % (control group), 8.8 % (second group) and 9.5 % (third group). Same rates for the next 25 days period were correspondingly 9.1 %, 9.6 % and 15.8 %. It is seen that postnatal death rate for the third group animals was somewhat higher than that in the second and control group. This effect can be caused by a long term influence of phytoestrogens and other bioactive compounds coming to the organism from GM soybeans.

The researches results testify to absence of negative influence of the thermally treated genetically modified soybeans on the genesial functions of rats and posterity development third generation. Investigated comparison of postnatal posterity development in control and experimental the groups did not find out meaningful differences. The probed indexes were within the limits of physiology norms, characteristic for rats.

Keywords: traditional soybean, genetically modified soybean, rat’s females, posterity, postnatal development, survivability, physical development