Revista Terminada 228

Transgenic foods.
Genetic engineering or recombinant
DNA technology is the science that
manipulates DNA sequences (which
normally encode genes) directly,
enabling their extraction from a given
biological taxon and its inclusion in
another, as well as the modification or
elimination of these genes. In this, it
differs from the classic genetic
improvement based on selection,
which modifies the genes of a
population indirectly, through directed
crosses. The first strategy, genetic
engineering, is circumscribed in the
discipline called plant biotechnology.
It should be noted that the insertion of
groups of genes and other processes
can be done by plant biotechnology
techniques that are not considered
genetic engineering, such as the
fusion of chromoplasts.
The improvement of the species that
will be used as food has been a
common motif in the history of
Humanity. Between 12,000 and 4000
a. C. an improvement was already
made by artificial selection of plants.
After the discovery of sexual
reproduction in plants, the first
intergeneric crossing (that is, between
species of different genera) was
carried out in 1876. In 1909 the first
fusion of protoplasts was made, and
in 1927 mutants of higher productivity
were obtained by irradiation with X-
rays of seeds. In 1983 the first
transgenic plant was produced. At this
time, biotechnologies manage to
isolate a gene and introduce it into a
genome of the bacteria. Three years
later, in 1986, Monsanto, a
multinational company dedicated to
biotechnology, created the first
genetically modified plant. It was a
tobacco plant to which a resistance
gene for the antibiotic Kanamycin was
added to its genome. Finally, in 1994
the marketing of the first genetically
modified food, the Flavr Savr
tomatoes, created by Cal gene, a
biotechnology company, was
approved.7 These were introduced
with an anti sense gene with respect
to the normal gene of
polygalacturonase, an enzyme that
causes the degradation of cell walls in
mature fruits, so that the fruit can
stand longer without being damaged
once harvested, and has greater
resistance to damage due to
handling, such as scratches or
bumps. But a few years later, in 1996,
this product was removed from the
fresh market, largely because of its
insipidity, and also because, without
decomposing, it ended up being
unappetising, with a soft skin, a
strange taste and changes in its
composition. These tomatoes are still
used for the production of preserves
and juices.
In 2014, transgenic crops are grown
on 181.5 million hectares in 28
countries, from countries in various
developments. In the year 2015, in
the United States, 94% of soybean
plantations were of transgenic
varieties, as well as 89% of cotton
and 89% of corn.