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Introduction to genetic engineering.

http://www.eschooltoday.com/gmo/genetically-modified-foods.html

You may have heard that many foods (plants and animals) these days have questions around, as to whether they have been grown naturally or have been manipulated in some way. These are genuine concerns as biotechnology has entered into new areas where DNAs of plants and animals have been combined to create new DNAs that never existed.

It is VERY important to understand what DNA and Gene is. DNA simply means Deoxyribonucleic Acid. It is a hereditary molecule that is found in almost all living things (cells). DNA carries a code (information) that genes use to make living things grow. It is found in all cells in structures called chromosomes.

Genes are instruction manuals in our body. They are molecules in our body that explain the information hidden in our DNA, and supervises our bodies to grow in line with that information. READ MORE HERE

With that brief DNA and Gene explanation, let us see this scenario.

A scientist wants to make blue apples: The scientist decides on the intent or reason for making blue apples. He can get a plant with blue fruits (say blue berries). He cuts out a piece the blueberry DNA and inserts it into the apple’s DNA. He plants the new apple seed and the apple tree produces blue apples instead of red.

But it is not plants alone — if he want a cow to have some desired traits such as high milk production, he can get the DNA of a cow with that trait and fix its DNA into the new cow, so that the recipient cow will have a high milk production trait.

Some time back farming practices like Simple Selection, Crossing, Interspecies Crossing, Embryo Rescue and Cell Selection were used to propagate crops and animals with better qualities. The concept is what drives genetic engineering today.

It is worth knowing that biotechnology or genetic engineering has the capacity to manufacture entirely new animals or plants, from merging cells from different sources. It can get a bit scary on the face of it, but in this lesson, we shall look at what the real issues are, in terms of foods that we eat.

It is important that you read about DNA and GENES (click here) to help you understand this better.

What is genetic engineering or genetically modified organisms (foods)

The words Genetically Modified Organisms(GMO), Genetically engineered (GE) and Biotechnology are often used interchangeably, but Genetic modification is simply the addition of new DNA to an organism or living thing, thereby modifying its genetic make-up.

It is the use of modern biotechnology (or gene technology) tools to introduce new traits (characteristics) into organisms, either from related and non-related organisms.

For example, a DNA from a plant (Plant X) that has high resistance to pests can be copied and introduced (added) to another plant (Plant Y), so that, the Plant Y will have the pest resistant trait.

Note that the DNA of an organism (e.g fish) can be modified by a DNA from a plant, which is a completely non related organism.

Another example is that, sometimes chemicals used in farming, such as herbicides end up killing lots of the crops planted, together with the weeds. Here, DNA from a herbicide resistant plant can be copied and added to the cells of the food crop so that the food crop will withstand herbicides when they are applied to the crops.

The concept of genetic engineering in not new, in fact it has been used to produce many blood, milk, lab mice types for research and pharmaceutical purposes for many years now. In recent time, the technology has been applied to plants and animals for food purposes, and that is why the argument has heated up.

You may not be able to tell a genetically modified fruit (e.g. strawberry) from its natural counterpart. They may look the same, but their cell DNA make-up will be different. Both fruits come from strawberry shrubs, but the shrub of the GM fruit would have produced fruits in a relatively shorter time period, or the GM fruit may have some toxin DNA in it which made it resistant to pests and diseases.

How is genetic engineering done?

Let us see this scenario: A scientist wants to produce a rice seed with higher protein content.

First he identifies a plant with a high protein content characteristic, such as a bean. Then he studies the genetic make-up of that bean carefully. The bean seed is called the donor organism.

Next he finds a viable rice seed, and studies its DNA carefully too. This is because he has to understand how to insert the DNA from the bean seed into the rice seed. The rice seed is the recipient organism.

Next he isolates the genes from the donor organism, the bean. This process is called mapping. This genetic isolation is done to take out only the desired protein-making trait (or DNA).

He makes several copies of the bean gene and inserts them into the gene structures of the rice. This is a carefully orchestrated laboratory process and many attempts are made to get it working right. This process is called Transformation.

The new gene (now called a transgene), with the desired trait, is transferred into the recipient cells (rice cells). This process is aided by some special bacterium and equipment and the scientist then ensures that the new genes are properly fixed in cell structure of the seed.

Once genetic engineering is complete, traditional breeding can continue normally, and the new seeds from the parent plant will have the new gene or DNA structure. This means traditional breeding will continue, and the genetic engineering only added some new or desirable traits to the collection.

GM and cloning: what is the difference?

Cloned animals are different from Genetically Modified (GM) animals, even though they are all results from the tools of biotechnology.

Genetic Modification (GM)

This introduces new genes into an organism. That means the recipient organism’s genes are now different from its parents genes (or from its original genes). When that new organism has offsprings, they are NOT clones. They are offsprings that will carry the new genes that were introduced to the parent. The new offsprings will also pass on that gene to new generations of offsprings. The entire line of generations, from the originally modified organism will all be called GM animals.

Cloning C

loning is very different. To clone something means to duplicate (or make an exact copy of something). Genetically, cloning is the creation of an exact copy of an organism. This means that the DNA or genes of the cloned organism is the same as the original.

For example, a scientist can a take female egg cell of a pig and fertilise it with a male sperm cell of a pig. At the fetilised-egg (zygote) stage, he can duplicate the zygote into 5 or 6 zygotes and place them into different female pigs to carry until they are born. All 6 of the piglets will have the same DNA even though they were birthed by different mothers. All 6 piglets can be called clones.

Cloning is a very common process in plants too. For example, if you plant from the cuttings of a crop, you are reproducing by asexual means. With cloning, no new genes are added. It is important to remember that a cloned animal was born by asexual reproduction, not sexual reproduction.

Why do we need gmo?

The developers of GM foods believe that genetically modified organisms will have lower prices, higher nutritional value and taste, and durable in terms of produce quality. More importantly, they believe that the plants will be more resistant to droughts, pests and weeds. Earlier, the main aim was to increase crop protection, but its perceived success has empowered the developers to explore into new areas of modifying organisms to yield even more radical results.

Some organisms are constantly being attacked by pests and some insects, and traditional methods of fighting them are just too costly and painful. So just like a flu shot, researchers believe the DNA from a virus can be fixed into the DNA of the crop, and make it more resistant to that virus.

Before we look at the arguement for and against this technology, here are a few reasons why GM foods are produced: to be insect resistant, virus resistant, and/or herbicide tolerant.

To this end, scientists have:

Introduced genes for toxin production into crops, making the crops require less insecticides on the lands on which they are planted

Introduced genes from some viruses into the crops, thereby making them less susceptible to diseases and therefore increasing its produce

Introduced some genes from some bacterium that makes the crops resistant to some herbicides.

The net resuls for all of this, is increased crop yield and higher production.

Genetic engineering debate:

Uncertainty

The biggest worry in GMO technology perhaps is the uncertainty surrounding it. Many people feel that we may be going onto an area that we cannot control if it gets out of hand. Maybe it is too late now, because we have all (very likely) already consumed lots of GM foods. Whiles there is little research on the real effects of GMO on human health, it is widely known that GM foods are safe for consumption, at least in the short term. The debate is a very heated one.

Food redistribution and food waste

But people speaking against GMO have a different point of view. They argue that feeding the worlds hungry and malnourished can be achieved by redistribution of food supplies. They argue that there is a lot of food waste in many of the countries that are pushing for GMO. If they really did care, they could invest in cutting the waste and distribute the surpluses to the most needed places. That sounds great, but is that possible?

Transfer of allergenic genes

Some people react to some food types. Transferring allergenic genes can result in contamination of natural foods and open up the range of allergic foods for people. For example, an allergenic Brazil-nut gene was inserted to a transgenic soya bean variety, but luckily the effect was noticed before it was released into the market. — Source: Weighing the GMO arguments. FAO

Environment

There is also concerns about the environment. The use of heavy chemicals on crops means that the land will absorb the chemical residue. Weeds that were killed will contain chemical residue, posing a threat to soils and living organisms in them.

Food supply

Hundreds of millions of people in the world are malnourished and hungry. Where is the food going to come from if we depend on natural farming practices that we have used all along? Many people speaking for the use of GMO say that the technology will make farmers in developing world (and all over the world) combat drought, pests and weeds more effectively and increase yields at local levels. Local farmers will need less effort to produce a higher yield.