“65 years after the famous discovery by Watson and Crick about the helix structure of DNA, unknown aspects of the structures and interactions of genes in organisms continue to be revealed, with various epigenetic factors and with the environment, showing that manipulating genetically DNA is a terrible idea, due to the many unforeseen effects that it entails. "
A team of Australian scientists recently verified the existence of DNA structures that are different from the double helix that we know. The new structure had been observed in vitro, but never in living human cells. At the same time, another team of researchers in Switzerland reported that trying to create resistance to a virus that affects cassava with CRISPR-Cas9 technology accidentally created a new pathogenic virus. It is one more of the possible adverse effects that this and other new genetic engineering techniques can have, which contradicts the abundant pseudoscientific propaganda that tries to convince us that they are fast, safe and cheap.
65 years after the famous discovery by Watson and Crick about the helix structure of DNA, unknown aspects of the structures and interactions of genes in organisms continue to be revealed, with various epigenetic factors and with the environment, showing that genetically manipulating DNA is a bad idea, because of the many unforeseen effects that it entails.
The new DNA structure was identified by Daniel Christ's team from the Garvan Institute for Medical Research and named it an interleaved motif structure (i-motif). The results of the study were published on April 28 this year in the journal Nature Chemistry (see here).
The discovery confirms that our DNA has more intricate symmetry than assumed and that those structural variants affect how our biology works. When most of us think of DNA, we think of the double helix, says antibody researcher Christ. This new research reminds us that totally different DNA structures exist and that they could be very important to our cells (see here).
The interspersed motifs are described as a twisted knot of four strands, in which the chemical elements that make up DNA are associated in a different way than known: the bases or letters of DNA are joined together with an equal one, for example the C (cytosine) with another C or G (guanine) with another G, something that never happens in the double helix.
The i-motifs were visualized for years in the laboratory, but never in living cells, so it was questioned that they really existed. According to Mahdi Zeraati, the first author of the Australian study, this is just one of the structures other than the double helix that could exist in the body; Quadruple DNA structures were also visualized in 2013 and there could be more, even triple and cruciform.
In the study that confirmed the existence of the interspersed motifs, the researchers inserted a fluorescent marker antibody, so they could see these structures appear and disappear in real time. The i-motifs are located near regions of DNA known as promoters, which turn the functions of genes on or off, as well as in telomeres, another section of DNA related to cellular aging.
Zeraati thinks that the fact that they appear and disappear is an indicator of their function: apparently they intervene in the activation or deactivation of genes, so it is highly relevant to better understand their function. This feature is also what made it difficult for researchers to see them in living cells in our bodies.
Separately, a study by Devag Mehta et al, from the ETH institute in Zurich, published on May 4, 2018, reports that when trying to create resistance to a virus in cassava by means of genetic engineering with CRISPR-Cas9, from 33 to 48 per One hundred of the edited viruses developed a single nucleotide (single letter) mutation, which created a resistant virus. The study also warns about the risk of these new resistant viruses spreading in the environment (see here).
The authors do not question the technology for other applications, but warn about the risks in this particular case. Mehta, lead author of the study, also mentions on his Twitter account that he is amazed at the pressure he has received not to spread negative aspects of the use of CRISPR-Cas9.
Indeed, there is a great mobilization of the biotechnology industry - including Monsanto-Bayer and DowDuPont, which have licenses to use this technology in agriculture and food - to unlink this and other new biotechnologies from previous transgenics, trying to deceive the public that now they are safe technologies.
Transgenic transnationals try to ensure that new biotechnologies such as CRISPR-Cas9 are not regulated, not even under current biosafety laws, arguing that the final product does not contain new genetic material. The issue is under strong debate in the European Union and the United States, but regulations have already been approved - in favor of companies - in Argentina and Brazil, although they have been contested by popular movements and critical scientists (see here).
Precisely, the experience of the Swiss team shows that there can be negative impacts, whether or not there is visible genetic material in the final modified product. But above all, the fascinating discovery of unknown DNA structures and their possible functions confirm once again that living organisms and their interactions in evolution are of enormous and wonderful complexity that we are far from fully understanding. For this reason, that a few transnational companies and the scientists that serve them manipulate living organisms is a perverse experiment with nature, health and the environment.
By Silvia Ribeiro, ETC Group Researcher