Download What is Genetic Engineering

What is Genetic Engineering
Genetic engineering is one of the most promising, challenging and upcoming field in Biotechnology.
What is genetic engineering? Let's get an insight of this pretty new and interesting field. Read on if
biotech interests you.
We all know that living beings are made up of genes. Every protein or enzyme is coded by a gene
responsible for controlling a particular trait or function. Genes are supposed to be the carriers of
hereditary information from generations to generations; more precisely responsible for the genotypic
and the phenotypic characteristics of an individual. Scientifically, genetic engineering is the genetic
manipulation or alteration in the genetic makeup of an organism which otherwise is not possible. It is an
artificial/synthetic process using the Recombinant DNA Technology which is way different from the
natural breeding techniques. The organisms produced, thus, are referred to as genetically modified
organisms (GMO's) or transgenic organisms. Genetic engineering is very much related to other
biotechnological fields like animal and human cloning. What is genetic engineering? Let's find out.
What is Genetic Engineering Used for?
Genetic engineering has had wide applications in almost all fields related to biotechnology wherein the
genome of the organism is involved. The process of transfer of genetic material from one organism to
another using a vector or carrier is scientifically referred to as transformation. In fact, all the
experiments have been performed on bacteria, crops and many animals mostly mice, though human
experimentation has not been possible due to obvious reasons.
Direct Methods of Transformation
Microinjection, macroinjection, bombardment techniques/biolistics, electroporation, liposome
mediated transformation, and transformation using chemicals like silicon carbide fibers.
Indirect Methods of Transformation
Vector based transformation; vectors include bacterial plasmids (Agrobacterium mediated transfer),
lamba phage, and bacteriophage (phage particles are highly efficient in transforming).
What is Genetic Engineering in Humans?
In humans, the technique remains the same but involves transforming human genes to change the
existing phenotype. Genetic manipulation has been done to modify certain mutagenic or disease coding
genes, as a part of treating some genetic disorders, apart from producing drugs and vaccines. It has also
been used to increase the longevity, and immunity of an organism and more precisely to study the gene
expression. Human genetic engineering is said to be of 2 types; somatic wherein the somatic cells are
transformed and germline wherein the transformation is involves changes in the egg or the sperm cell
and thus inherited. The first almost successful trial of genetic manipulation was for people suffering
from Severe Combined Immunodeficiency (SCID), in 1990, that resulted in people getting functional
immunity which they were deprived of. Genetic engineering has been used for infertility problems as
well wherein the infertile female acts as a surrogate mother and is successful in producing a child. Other
modifications in human genetics are on low priority since the success rate has been doubtful.
Genetic Engineering Steps
Isolating the Gene: Selection of the required gene and isolation is a prerequisite to start the process. The
desired gene to be transferred is isolated and multiplied using PCR (polymerase chain reaction).
Alternatively, it might be a part of the genomic library (libraries containing fragments of DNA of one
particular genome).
Constructs: The gene that is isolated needs to be checked for expression. Every gene is made up of the
promoter, selectable marker gene and the terminator. The promoter region is responsible for
transcription of the gene which is terminated on reaching the terminator region. The selectable marker
gene confers antibiotic resistance that helps to distinguish transformed cells. However, the gene cannot
multiply on its own, rather has to be combined with foreign DNA or a vector wherein the process is
carried out using restriction digestion enzymes, ligation enzymes and molecular cloning using
polymerases.
Transformation: Bacteria have been widely used to take up the gene or foreign DNA with help of the
above transformation methods. After integration, the gene or DNA replicates using the host replication
system and produces many copies of itself.
Selection and Confirmation: It is possible to differentiate the transformed cells from the non
transformed ones by growing them in the presence of the antibiotic coded by the selectable marker
gene. Another method is to use DNA probe complementary to the inserted gene which will specifically
bind to the gene of interest and can be traced and confirmed using DNA mapping, Electrophoretic
techniques like Southern blotting, and Bioassays.
Genetic Engineering Pros and Cons
The benefits of genetic engineering are evident in the fields of agriculture, environment, and food
production. Having said that, since it is a field involving too much of research, it's obvious for it to have
its share of negative effects. Let's see what they are after going through the genetic engineering
advantages.
Pros

Many genetic disorders, complications like diabetes, cystic fibrosis have been cured by genetic
engineering in humans since it involves removal of faulty genes and modifying cells to produce
the desired trait which was missing previously; by gene therapy. Insulin and human growth
hormone are the best examples wherein the genes coding for these hormones are being
transformed in bacterial cells on large scales to elevate the hormone production.

Animal cloning and transformation has been exclusively done on mice. The first successfully
transformed animal was Dolly, better known as the cloned sheep though the ethical issues of
cloning have been a major hindrance as far as research is concerned.

Genetic engineering has been used over and over to produce pest, disease resistant plants and
also highly nutritive plants. The best example is Bt cotton plants wherein Bacillus thureingiensis
has been used to insert various pest and disease resistant genes in crops.

The genetically modified foods have helped masses with high amounts of nutrition. The golden
rice, and the flavor savor tomatoes are the best examples of genetic engineering in food.
Cons

Since genetic engineering involves severe experimentation, there are high possibilities for genes
to produce undesirable mutations and traits leading to allergies in crops that hamper its
nutritional value. The resultant traits might give rise to new pathogens that are harmful to the
entire ecosystem.

This technique requires insertion of the desired gene at the exact location for which great skill is
required especially when it involves many risk factors. Also, transformation of a single gene is
difficult since it codes for multiple traits.

Genetic engineering is an expensive technique to carry out. It requires skilled manpower,
excellent and accurate devices and chemicals, and highly sophisticated laboratories which are
not affordable to laymen.

Lastly, one cannot ignore genetic engineering ethics and debatable issues involved in use of
animals and plants for manipulation which are supposed to be God's creations'.
Okay. This was some info on what is genetic engineering. It's a great field to work in, if one's interested
in research and aware of the pros and cons of genetic engineering. It requires your thorough dedication,
hard work and skill since you are dealing with biological things. This field contributes to immense
amounts of research that has started-off long back, but is continued and will always continue as long as
biotechnology exists.
By Mrunmayi Deo
Published: 10/14/2010