Intervention on the genomes. Part 1

Today we are going to talk on a controversial theme which is the edition of the genomes. We use the word editions to mean modifications, to mean intervention on the genomes. And first of all, we have to talk on terminology in the sense that there are words that sometimes are being used and sometimes some of these words get dirty with time and people change them, so this happens in many issues and also in biology. What we have to understand is the meaning of genetic engineering which is the modification, manipulation, the direct changing manipulation of an organism genes using biotechnology. Biotechnology means techniques used in biology to make this kind of modifications.

Nowadays we mostly talk on genome editing, editing in a similar way of editing a book, it’s a type of genetic engineering in which DNA is inserted, deleted, modified, replaced… in the genome of a living organism. So, the idea is to make changes, and the basic issue is to know the techniques of that, why we do that? Why we want to do that? Why this may be interesting? And which are the possible implications of this kind of technology. We say that an organism that is generated through genetic enginery is considered a genetic modified (GM) and the resulting entity, the living being, is a genetic modified organism (GMO) on which the press talks so much.

In research GMOs are used to study, to understand the gene function and the kind of modification may be a loss of function of a given gene, the gain of function, at the very end is to try to understand the functions of the genes doing this kind of manipulation. One of the best-known is a knocking out of genes, so knock out is just going into an organism, the genome of an organism, and inactivate a given gene to understand the implications of that and this is fundamental nowadays to understand the bases of genetic diseases.

At the very end, so, we have different ways of modification an organism; and the basic differences between what we do now and what has been done in humanity for millennia is that now we try to understand exactly which modification we introduce in the genome, while during the millennia of animal and plant modification has occurred through technologies that were not based on genetic but were based on the productivity, on the desire, on the selection of the breedings.

Let’s have a look at the diversity of dogs, for example, let’s have a look at the diversity of plants that come from a single one, the wild cabbage, in which we have a huge variety of morphologies, of physiologies and in all these cases, this comes from a genetic manipulation of the species through domestication choosing what people wanted. So, there is a selective breeding in which humans have been selecting the conditions, the properties, the physiologies, the morphologies of plants and animals to get what they wanted.

We have to pay attention to a single fact: all the domesticated animals, all the domesticated plants survive on Earth because humans take care on them. None of them are pure, normal, natural, whatever word you want to use for that and what we have produced is a huge genetic change without knowing exactly which changes were there.

So, we have done through domestication huge amount of changes in the genome of all the species that are with us –species that we eat, species that we use, species with who we live– and in all the cases this has been a very strong selection and several techniques have been used, so the selective breeding has been the main one but also hybridization, a propagation by vegetative cloning like in the potato for example.

So, the main idea is that the modification of the genome has been done all the history since the Neolithic in humans, beginning in the last ten thousand years and nowadays we keep doing that in the traditional way but also we have learned in the last decades to go and make specific changes and trying to guess, to be sure, to approximate the phenotypic changes that will imply a specific gene modification.