Natural Genetic Engineering vs GMOs

GMO-Jumping-Gene

The following is an extract from a recent article the Institute of Science in Society (ISIS) explained the distinction between natural genetic engineering and very un-natural genetic engineering (GMOs). As always, the theme throughout most of my posts relate to evolution and the revolution in evolution, AKA: Professor James A, Shapiro’s proposal of natural genetic engineering vs. natural selection as a means of evolutionary change. The report below focusses on the dangers of GMOs in relation to NGE (Natural Genetic Engineering).

ISIS Report 05/08/14

Artificial versus Natural Genetic Modification & Perils of GMOs

The precision, complexity, and all-pervasiveness of natural genetic modification leave organisms and ecosystems particularly vulnerable to artificial genetic modification by Dr Mae-Wan Ho

Invited lecture at 1st Forum of Development and Environmental Safety, under the theme “Food Safety and Sustainable Agriculture 2014”, 25 – 26 July 2014, Beijing, China

 

“Back in the mid-1970s to 1980s, the primary motivation for both artificial genetic modification and the human genome project was classical Watson-Crick molecular genetics based largely on the Central Dogma that genes control the characteristics of organisms in linear causal chains. That picture has been overwhelmingly contradicted by empirical findings that began to trickle, then stream, and pour out of laboratories. The new genetics is telling us in no uncertain terms that the genome is fluid and dynamic. It is constantly conversing with the environment in circular networks that mark and change genomic DNA in myriad ways, with both DNA and RNA taking part in transmitting genetic information and in executing and altering genetic information in real time.  I use the term ‘natural genetic modification’ for the totality of changes made by organisms in the genetic information of cells and tissues as part of their survival strategy, and some of the changes are passed on to the next generation(s) [2]. Artificial genetic modification invariably interferes with the natural process, and I suggested that is [3] Why GMOs Can Never be Safe (SiS 59).

Natural genetic modification employs the same copy, cut and splice tools as artificial genetic modification, but with much greater finesse and precision. (Artificial genetic modification is possible only by usurping the tools of the natural process.) It enables organisms to express genes in different parts of the genome at the appropriate levels, or mark and modify them, as and when required in specific cells and tissues.

To produce even one protein – originally thought to be single continuous message – requires elaborate cut and splice operations. The international research consortium project ENCODE (Encyclopedia of DNA Elements) data have revealed that the vast majority of genomic DNA include ‘non-coding’ segments [4, 5]. The ‘gene’,  a theoretical construct that has never been possible to define rigorously, is now known to be scattered in bits across the genome, overlapping with bits of multiple genes that have to be spliced together before translating into a protein. The term used for the bits is ‘coding sequences’ or exons.

The expression of each gene already requires the assembly of a small army of special molecular engineers. The human genome contains about 20 000 protein-coding genes, most of which would be active in one cell or other of the body at any one time.

That’s not all. Humans contain practically the same number of protein-coding genes as nematodes that have only 1 000 cells compared to humans’ 1014 cells. In contrast, non-protein-coding DNA, largely absent from bacteria, increases with increasing complexity of organisms [6] (see [7] Non-Coding RNA and Evolution of Complexity, SiS 63), reaching 98.8 % of the human genome. Much of that was considered ‘junk DNA’ until geneticists discovered to their surprise that most of the sequences (latest estimate > 85 % [8]) are dynamically and differentially transcribed in tissues and cells, into many families of short and long non-coding (nc)RNAs. These ncRNAs regulate gene expression and genome architecture by interacting with DNA, RNAs, proteins, and other cofactors.

Cells and tissues also respond to their environments by recruiting different contingents of molecular engineers for marking and modifying, cutting and splicing specific RNA or DNA, or remodelling chromatin (complex of DNA and histone proteins) at specific genome locations. We know only a small fraction of the vast amount of details involved. But it is already so remarkable that leading molecular geneticist James Shapiro at University of Chicago is saying that practically nothing happens at random [9, 10]. Cells and their genomes are not [9] “passive victims of replication errors or DNA damage” (see [11] Evolution by Natural Genetic Engineering, SiS 63). Instead, just about everything, including so-called random mutations happens by “natural genetic engineering” (almost the same as what I call natural genetic modification).

Indeed, cells have special proof-reading and error correcting functions to eliminate and repair damaged/mutated bases in the genetic material, getting errors down to below 1 in a billion bases under normal conditions. But during starvation, bacteria can also target precise mutations to specific sites in the genome to generate new metabolic functions [9, 10]. Such ‘directed’ or ‘adaptive’ mutations are now well-documented in bacteria as well as human cells (see [9] Non-Random Directed Mutations Confirmed, SiS 60). The human immune system executes accurate cut and splice genome rearrangements to create a large variety of immunoglobulin chains and also targets hypermutations to specific immunoglobulin variable sites to generate huge diversities of antibodies for defence against invading pathogens.

I have only given you a tiny sampling of the organisms’ remarkable feats of natural genetic modification, which are precisely targeted, context dependent, complex, and negotiated by the organism as a whole. It is a well-known paradox that both plant and animal cells maintained in culture undergo uncontrollable mutations and chromosomal rearrangements (somaclonal variations) [13], in contrast to cells within the healthy organism, which show extremely low levels of ‘random’ mutations.

Artificial genetic modification acts against and undermines the natural process

The targeted precision and complexity of natural genetic engineering/ modification makes clear that genetically modified organisms (GMOs) created by the crude methods generally used until very recently can only be highly unsafe [2, 3]. Much current effort is dedicated to ‘genome editing’ using guided or otherwise specific DNA cutting enzymes to alter DNA sequence at target locations in the genome. But off-target, cytotoxic effects continue to dog the latest attempts [14-16]. Artificial genetic modification invariably interferes with natural genetic modification, and it is well-nigh impossible to avoid doing so. It depends on disrupting and overriding the organism’s own minutely choreographed process, the result is uncontrollable and unpredictable off-target effects….”

 

More of this article can be found at  ISIS article

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s