SCIENCE TRIBUNE Thursday, November 21, 2002, Chandigarh, India

Rewards and dangers of genetic engineering
Rajeev Goel
enetics is the fundamental biological science, for without genes there is no life. Any biological process can be fully understood only after the detailed analysis of the structure of a gene and its corresponding function. Geneticists nowadays do this detailed analysis by using modern methods and sophisticated techniques of genetic engineering. 

2,000-year cycle of El Nino
l Nino, the weather phenomenon blamed for causing devastating droughts, storms and floods around the globe, work on a 2,000-year cycle, scientists have said. The frequency of El Nino events peaked about 1,200 years ago during the Middle Ages and will probably reach another high in the early part of the 22nd century.


  • Flying limousines of future

  • Animals feel climate change




Rewards and dangers of genetic engineering
Rajeev Goel

How the gene transfer takes place?

It is imperative to be familiar with the basic technology associated with the gene transfer to appreciate the science of genetic engineering. The scientists first identify and isolate the gene of interest to be transferred from A (donor) to B (recipient or host). Once isolated, the gene is put into a vector by using certain enzymes which form part of the genetic engineering tool kit. A vector is something that ultimately carries the gene into the nucleus of the host or recipient cell. These vectors are mainly bacterial plasmids (circular piece of bacterial DNA) or viruses. Another method is the use of “SHOTGUN” technique scientifically called as “Bio-ballistics”. It uses tiny gold particles coated with the gene of interest. The shotgun shoots these tiny particles into the animal or plant cell, hoping to land a hit somewhere in the cells’ DNA thereby creating transgenic animals and transgenic plants.

Genetics is the fundamental biological science, for without genes there is no life. Any biological process can be fully understood only after the detailed analysis of the structure of a gene and its corresponding function. Geneticists nowadays do this detailed analysis by using modern methods and sophisticated techniques of genetic engineering. Genetic Engineering (GE) is also called as the science of gene cloning, DNA technology and genetic modification, though it comes under the broad heading of Biotechnology.

The genetic engineering involves either the alteration of a particular gene within a species e.g. changing the colour of flower petals from red to white by permanently shutting down the gene coding for red colour, or transferring the genes and segments of DNA from one species e.g. fish, and put them into another species e.g. potato. The leaves of one such genetically engineered potato crop glow when the plant needs watering because the gene for “glow” from jellyfish has been inserted into the potato crop. Such plants and animals carrying an alien gene i.e. one from a different species are called transgenic plants and transgenic animals, respectively.

The GE thus enables us to breakthrough the species barrier and to shuffle information between completely unrelated species. The genetic engineering, in fact, offers the ability to change the very nature of nature for it has added up new weapons in terms of technology to armoury of geneticists. This in turn has opened new vistas for the scientists to manipulate the genes in various ways to achieve certain goals in pure, applied and medical sciences.

The genetic engineering in the field of agriculture has improved the productivity and growth of crops. It has led to the development of crops with better ability to fix up atmospheric nitrogen or with better tolerance in extreme conditions like cold, drought and salt where the plants could not grow otherwise. There are certain genetically modified crops like soya, maize, cotton, tobacco etc commonly called as “GM crops” which have been claimed to have certain food advantages as well as resistance to insects and pests.

The resistance to insects and pests is achieved by incorporating an insect killing toxin gene from bacteria into these crops. The genetic engineering through gene manipulations has also increased the production and nutritional value of fruits and vegetables in terms of carbohydrates, starch and proteins besides extending their shelf life and making them more appealing with respect to colour, shape and size.

The terminator seed containing the “terminator gene” is also an outcome of genetic engineering. The terminator seed of a particular plant variety (wheat, rice, cotton, tobacco, corn, millet, pulses etc.) however, are sterile seeds that are incapable of growing or propagating after one season.

In the field of medicine, it has resulted in the production of new drugs, various human proteins of interest like different components of human blood, human hormones e.g. growth hormones and insulin, vaccines, including DNA vaccines and ultimately gene therapy to cure genetic disorders and the production of cytokines to combat cancers.

The genetically engineered human proteins and hormones are produced in microorganisms, plants and animals, particularly the mammals like cow, mice, sheep, goat etc. The human bio-molecules in these transgenic animals are secreted into the milk of lactating animals, which are later on purified.

Xeno-transplantation i.e. transplanting across the species e.g. transplanting a heart from a pig to a man is also an outcome of new genetics. The GE has made possible the in vitro fertilisation i.e. union of a sperm and an egg in a test tube. This has saved us from the horror of pregnancy and abortion. It has also provided an opportunity to clone animals e.g. mouse with desired characters or traits like blue eyes, purple hairs and large growth and that too from the non-reproductive cells in the body.

It also allows making an alteration in the reproductive cells of an organism itself so that a particular trait can be passed on to next generation.

The day is not far off when one may use it as tool to enhance human capabilities like IQ, great strength and power. The parents may then wish to have “Super Children” with the desired capabilities as per their requirements!! In future one may in fact be able to get rid of conditions like overweight, short stature and black complexion by using tools of genetic engineering. This has become all the more possible after the recent translation of blueprint of life which had involved deciphering billion of strands of DNA.

The DNA technology in veterinary has provided the mankind with leaner meat and larger animals with faster growth. One such example is the salmon, genetically engineered with growth hormone gene. It grows too big and is widely available in the meat market. The cloning of Dolly, the sheep and Cumalina and her two generations of cloned mice are the gift of genetic engineering. The Friesian cow, common black and white pattern efficient milk producing European cow is also the result of GE.

The GE led to the generation of celebrated “Super mouse” in the early 1980s. Such mice because of the over expression of growth hormones gene, grew some 2-3 times faster than normal mice and were twice the size of normal.

The current gene manipulation technology used in genetic engineering even allows custom made organisms to be produced e.g. bacteria that clean up the oil spills and produce useful industrial chemicals. The microorganisms are now tailor made to produce proteins by incorporating corresponding genes from infectious agents such as hepatitis virus or AIDS virus for use in vaccines.

The genetic engineering thus allows us not only to take out a gene from one type of organism and put into other type of organism but also enables us to steer the organism in our own way by modifying or adding a new gene within it. Genetic engineering, therefore, offers a major ethical dilemma. On the one side, there are great rewards of such a wonderful technology like production of improved varieties of plants/crops, nutritious foods, availability of human bio-molecules, new antibiotics, gene therapy to combat genetic disorders, availability of pre-marital genetic counselling to save ourselves from bearing children with genetic disorders etc. etc.

On the other hand, it has raised many doubts regarding these rewards too. Because there are reports that a) clones of Dolly, the sheep has developed arthritis at an early age; b) genetically modified potatoes are believed to have the damaging effect on the immune system of rats when tested; c) the Friesian cow has very painful udder; d) the xeno-transplantation like pig heart to human may transfer “non human genes” to the recipient; e) similarly, there are apprehensions that the plasmid and viral vectors used in human gene therapy may cause transfer of bacterial or viral genes even though the disease causing genes of these vectors are already made nonfunctional, f) the transfer of a terminator gene of a particular seed variety to other crops can cause sterility at a large scale which has led to the banning of terminator technology in India; g) salmon genetically engineered with growth hormones gene mainly grows too big, too fast but also turns green; h) few of the genetically modified plants have the decreased fertility and altered growth of roots and leaves; i) genetic engineering if used for enhancing the human capabilities will directly shape the evolution (which otherwise ought to occur naturally).

The list of these doubts and unpredictable side effects of such a science is expanding day by day. This has resulted in great hue and cry against such a technology by lot of NGOs and even scientists all over the globe. But we cannot straightaway discard the science of genetic engineering, as one must see the other side of the coin too. Along with many disadvantages are associated the advantages too. The only important point is that the core issue behind the ethics of genetic engineering needs to be studied rationally and thoroughly. The genetic engineering has no doubt become a central discipline in modern biology and one needs to use the tools of genetic engineering in such a way so as to avoid the misuse of such a technology that holds tremendous promise and excitement in basic biology, biotechnology and medicines for the years ahead.Top


2,000-year cycle of El Nino

El Nino, the weather phenomenon blamed for causing devastating droughts, storms and floods around the globe, work on a 2,000-year cycle, scientists have said.

The frequency of El Nino events peaked about 1,200 years ago during the Middle Ages and will probably reach another high in the early part of the 22nd century.

“El Nino operates within its own kind of 2,000-year rhythm, and because of that, we believe these periodic changes have had a major impact on global climate conditions over the past 10,000 years”, Christopher Moy of Standford University in California says.

El Nino is an abnormal warning of waters in the Pacific that distorts wind and rainfall patterns around the world. It has been linked to heavy rainfall in northern Peru and souther Ecuador and heat waves in the northeastern United States.

While studying at Syracuse University in New York, Moy and his colleagues discovered the first continuous records of weather events caused by El Nino going back thousands of years.

By studying sediment from Lake Palicacoacha in souther Ecuador, the scientists were able to track changes in whether systems across North and South America.

“About every 2,000 years, we see a lot of El Nino activity”, said Moy, who reported his finding in the science journal Nature.

“El Nino is an important part of our modern-day climate system. Likewise, our study shows it was also an important part of the earth’s climate system 7,000 years ago”, he added.

The scientists hope that by studying earlier El Nino cycles they can improve understanding of future climate changes.

Weather experts predict the current mild El Nino, which scientists have blamed for extending the dry season in parts of Asia, may strengthen this winter, increasing storms in the southern United States and causing drier conditions in the Midwest.

But the experts at the National Oceanic and Atmospheric Administration in the United States said it will be weaker than the 1997-98 El Nino that claimed thousands of lives and caused billions of dollars of damage worldwide. Reuters



Flying limousines of future

Aviation experts are brewing an aggressive plan to create a new generation of small planes that would be guided by a computerised flight control network and provide inexpensive air taxi service. These planes would have to be cheaper, possess simpler avionics, and fly faster than comparable aircraft available today. Eager to jump-start these revolutionary designs, NASA’s Langley Research Centre held a student competition.

The first place went to Alaris. Students in the University of Virginia’s engineering department chose an unusual blended-wing body design for their jet. The four-seater would employ two new, lightweight Williams EJ-22 turbafans to reach a top cruise speed of 529 mph. It would have a range of more than 2000 miles and computerised avionics for automated flight. The price tag: an estimated $1.35 million.

In blended-wing bodies, otherwise known as flying wings, the fuselage and wing function aerodynamically as a single unit. As a result, the planes weigh less, produce lower drag at cruise speeds, and consume less fuel. But a flying wing is inherently less stable: Matt Daniell, 21, a leader of the Alaris project, says it’s the equivalent of an arrow without its feathers.” That’s why this type of plane has never been used in general aviation, and only rarely elsewhere (the stealth B-2 bomber is the best-known real example, though Boeing in now experimenting with a flying-wing design for a future large airliner). To skirt the instability problem, the UVA students employed an onboard computer to facilitate airplane control.

Winglets would also help steady the Alairs. The swept-back wing shape makes it possible to position them toward the rear, where they would function the way vertical stabilisers and rudders do on conventional planes. The already quiet engines would sit above the fuselage to reduce noise — a key factor if small-plane aviation is to develop the way NASA wants it to.

The Alaris design is not without drawbacks. One judge noted that the plane’s steeply sloped door could make entering and exiting difficult, and that the extra interior volume created by the blended wing wasn’t particularly well employed. Popular Science

Animals feel climate change

Researchers braving Greenland’s frigid temperatures and tempestuous snowstorms have collected the first direct evidence that a change in the wind can alter identically the fate of diverse animal species living vast distances apart.

They observed the powerful influence of shifting climate on herds of caribou and musk oxen, separated by an impenetrable 600-mile glacial sheet that splits the world’s largest island. The locale’s special natural features made it an ideal setting for the unique study.

The survey of the massive mammals — living relics from the last Ice Age long adapted to breeding in sub-zero harshness — illustrates how Arctic species sensitive to the effects of changes in Earth’s weather patterns can serve as an early warning signal for the rest of the planet, the investigators said. UNI





Across :

1. An instrument to measure the depth of sea by noting the time taken for return of echo of sound from the bed.

8. SI unit of luminous flux.

9. Electromagnetic radiation having much shorter wavelength.

10. A white crystalline substance obtained by condensation of ammonia and used in medicine and vulcanized rubber.

12. Non-metallic material obtained from smelting of metallic ores.

13. A gnat-like insect.

15. An acid manufactured from Borax and used as a mild antiseptic.

17. Symbol for lead.

19. A unit that expresses the intensity of sound.

22. This group of radicals has hydrocarbons of paraffin series.

23. Dark, viscous organic material.

24. Abbr. used by doctors to write ‘No abnormality detected’.

25. Used in navigation technology to locate bearings of a transmitter called Radio Beacon.

26. Faculty of sight.

27. A specialized group on nutrition under Indian Council of Medical Research. (abbr.)

Down :

1. Natural Calcium Fluoride having colourless crystals but coloured impurities.

2. Containing trivalent Gold.

3. A mission set up by Indian government to achieve self sufficiency in oilseeds (abbr.)

4. A beat effect produced by superimposing two waves of different frequency and used in radio receivers.

5. This function is for a variable quantity.

6. An element having a valency of three.

7. A cereal used in bread and distilled for whiskey.

11. This acid is colourless crystalline solid and an oxide of Osmium.

14. Measure.

16. A device by which electric current flowing in one circuit can be passed to a second circuit.

18. Colour of crystalline cupric sulphate.

20. Unit of area measuring the cross section of nuclei.

21. An Indian government research lab. for radar development.

Solution to last week’s Crossword: