Download Scientific and bioethic reasons (complaints)

3rd South-European Bioethic Forum
Mali Lošinj, 20-22 September 2007
Scientific and bioethic complaints against the genetic enginering
Marijan Jošt
Agricultural College Križevci
Abstract
It is clear today that the general public opinion is against the genetic engineering (GE) on
plants and animals as well as genetically modifyed ingredients in food. Sadly, the main
support for GE comes from some educated academic people; even when their profession is
far from molecular biology and genetics, their belief in science is so firm that they rule out
any logical criticism and proclaim it as non-scientific.
The mistakes of GE and the wrong scientific approach of molecular biologists are presented
from the viewpoint of a plant breeder.
Besides the scientific mistakes on which the GE is based, bioethic reasons against the
acceptance of genetically modified organisms (GMO) is explained according to the Lošinj
declaration.
And last but not least, the economic and political background of genetic engineering will be
elucidated.
Key words: genetic engineering, science, bioethics, politics.
Introduction
To folow scientific and bioethic complainst against genetic engineering, we should first
explain what is genetic engineering. Just look at one of several definitions: Genetic
engineering is a set of biotechnological methods used to transfer foreign DNA segment
through biological barriers of different species. This event - transfer foreign DNA segment
through biological barriers of different species is also knovn as ‘Horizontal gene transfer‘.
Why horizontal? In nature, a common transfers of genes is from parents to ofspring, and
this is called 'vertical gene transfer'. Quite oposite is in case of gene transfer between
different, nonrelated species vhich is not hapeninh in nature over a short period of time. Jes,
here time is important, because even this 'horizontal' gene transfer could occours during
extremeli long period of time. For instance: throughout milenies of human being evolution
some foriegn genes vere incorporated in human body. So, today for instance, it is known
that 113 genes have been transferred into the human genome from bacteria.
Examples of crossings:
The same species (subspecies):
diferent cultivars of wheat or breeds of dogs
Closely related species:
donkey x horse = mule
Different species or families:
tomato x fish
YES
Sometimes
Sterile ofspring
NO
To obtain unnatural and upossible 'horizontal' gene transfer between diferent unrelated
species scientist are using special techniks:

Agrobacterium mediated transformation – the easiest and most simple plant
transformation, but many plants are not transformable by this method and it is not used
in GE now.

Particle bombardment: Coat small gold or tungsten particles with DNA and shoot them
into young plant cells or plant embryos. Some genetic material will stay in the cells and
transform them. This method also allows transformation of plant plastids. The
transformation efficiency is lower
which incloode an artificial DNA construction caled vector. Vector is a modified pathogen
virus or bacterium, used to perform transfer of the gene construction. Besides DNA
segment which is known to code certain desirable characteristics and which should be
transfered, in vector are incorporated also:
Promoter is from Cauliflower mosaic virus (CaMV 35S). The promoter (CaMV 35S) of the
35S RNA is very strong, and well known for its use in plant transformation. Its duty is to
start action of the inserted gene.
Marker (ABR gene) is used to prove successful transfer of DNA construction into the tissue
culture from which a new GMO will be developed.
Promoter
(CaMV 35S)
Inserted gene for
desired trait
Marker
(ABR gene)
Plants
A number of mechanisms are available to transfer DNA into plant cells:


Agrobacterium mediated transformation is the easiest and most simple plant
transformation. Plant tissue (often leaves) is cut into small pieces, eg. 10x10mm,
and soaked for 10 minutes in a fluid containing suspended Agrobacterium. Some
cells along the cut will be transformed by the bacterium, that inserts its DNA into
the cell. Placed on selectable rooting and shooting media, the plants will regrow.
Some plants species can be transformed just by dipping the flowers into suspension
of Agrobacterium and then planting the seeds in a selective medium. Unfortunately,
many plants are not transformable by this method.
Particle bombardment: Coat small gold or tungsten particles with DNA and shoot
them into young plant cells or plant embryos. Some genetic material will stay in the
cells and transform them. This method also allows transformation of plant plastids.
The transformation efficiency is lower than in agrrivatedbacterial mediated
transformation, but most plants can be transformed with this method.


Electroporation: make transient holes in cell membranes using electric shock; this
allows DNA to enter as described above for Bacteria.
Viral transformation (transduction): Package the desired genetic material into a
suitable plant virus and allow this modified virus to infect the plant. If the genetic
material is DNA, it can recombine with the chromosomes to produce transformant
cells. However genomes of most plant viruses consist of single stranded RNA
which replicates in the cytoplasm of infected cell. For such genomes this method is
a form of transfection and not a real transformation, since the inserted genes never
reach the nucleus of the cell and do not integrate into the host genome. The progeny
of the infected plants is virus free and also free of the inserted gene.
[edit] Animals
Introduction of DNA into animal cells is usually called transfection, and is discussed in the
corresponding article.
[edit] References
1. ^ Chen I, Dubnau D (2004). "DNA uptake during bacterial transformation". Nat.
Rev. Microbiol. 2 (3): 241–9. doi:10.1038/nrmicro844. PMID 15083159.^ Largevolume transformation with high-throughput efficiency chemically competent cells.
Focus 20:2 (1998).
3. ^ Transformation efficiency of E. coli electroporated with large plasmid DNA.
Focus 20:3 (1998).
1. Scientific arguments against GE
The mistakes of GE and the wrong scientific approach
2. Bioethic arguments against GE
Bioethic reasons against the acceptance of genetically modified organisms
3. Economic and political background of genetic engineering
References
Pelanda C. Global Ecopolicy - Preliminary Paper. GLOBIS, University of Georgia,
Athens, GA, USA <http://www.carlopelanda.com/italian/ricerca/Gloecopolicyjan02.htm>
Marijan Jošt
Agricultural College Križevci
M. Demerca 1
48260 Križevci
E-mail: [email protected]