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Gene Transfer.

posted Dec 8, 2014, 3:43 AM by Ranmini Perera   [ updated Jan 10, 2017, 3:49 PM by Upali Salpadoru ]

Our Genes Inside others

Few thousands of viruses can easily fit into a bacterium. Millions of bacteria may be accommodated inside the cell of an animal, a plant or a fungi.  Irrespective of their differences and abnormal proportions of size, it has become feasible to exchange genes among widely varying species.

Fig.1   If you become as big as N.Z, a bacterium will be the size of a cruiser. A virus would be  a passenger in that ship.
(Merely a rough comparison)

Fig.2.Gregor Johann Mendel (1822 -1884  ) 

Gregory Mendel who is considered as the father of genetics,was an Austrian monk  The search that climaxed by the double helix model of the DNA molecule demonstrated by Jimmy Watson and Francis Creek, was an arduous task accomplished over a long period by such greats as Swiss Friedrich Miescher(1869)  , Russian biochemist Phoebus Levene(1919), Canadian Oswald Avery, Austrian biochemist  Erwin Chargaff ,  US theoretical chemist Linus Pauling, and X-ray crystallographers as Rosalind Franklin(UK)  who had to pay with her young life,  and Maurice Wilkins (NZ) just to mention a few. Deoxyribo nucleic acid is a twisted  polymer  constituted of nucleic acid.

The similarity of the genes of all living things and the similar reactions they produce for  specific proteins, is a boon to microbiologists  The devoted study of viruses, yeast and bacteria revealed some intricate secrets in connection with our genes. For example the flu virus has only 15 genes while a human has 20,500 genes in each cell. But molecular functions remain the same.

It was the discovery of enzymes that opened up the manipulation of our genes.

 Year Enzyme Function Researchers
DNA polymerase

Catalyzes the synthesis of DNA

Dr. Arthur Kornberg

1959 Nobel Prize


DNA ligase

Sticks up the severed DNA strands

B. Weiss and C.C. Richardson
Restriction enzymes

Cutting the DNA strand at specific places.

Dr. Hamilton Smith, K.W. Wilcox, and T.J. Kelley
Diabetes, insulin deficiency, was a very common hereditary disease of the humans. Although this could be obtained from animals, some patients were allergic to  animal insulin. When the insulin gene was spliced off a human cell and inserted into E. coli bacteria, they synthesised the drug for us.  Big pharmaceutical companies quickly pioneered in developing ‘state of the art’ manufacturing devices, which came to be known as ‘bioreactors’  and help the healing process.

Neurofibromatosis is a genetically inherited disease where the nerve tissue grows tumours. NF1 is caused by a mutation on a gene located on chromosome 17 and NF2 on chromosome 22. There is no cure for NF (dermnet. nz) Biologists  inserted the NF gene into Yeast cells. The yeast cells changed their function.

‘One man a minute’ is the death rate due to cancer in United States. Cancer is abnormal growth of normal body cells. In the case of diseases caused by pathogens, drugs can be used to attack them but when the fight has to be against our own disloyal cells, the task is not easy. It is also not ethical to subject human cancer patients to rigorous tests.  It was the practice to test  pharmaceutical products on animals prior to human clinical trials. Animals or rather mammals could have been used on cancer research. Unfortunately cancer was not at all common on other mammals.  So we can hardly blame the scientist for developing a strain of mice with human genes who are susceptible to cancer. Now disease models of mice are available as AIDS mouse, Alzheimer mouse in addition to onco-mice. As to be expected the animal lovers are up in arms.

Fig.3.Rats became the first animals to have got a patent carrying our genes.

Some microbiologists soon , instead of steel bioreactors with gauges, timers and valves to switched over to living factories.  Mammary glands of sheep, cows and goats could produce milk with specific proteins required for the treatment of various diseases.

Roslin Institute in Scotland, attached to the University of Edinburgh, hit the news headlines in 1996 by the cloning of  ‘Dolly’ the sheep, the first mammal to be cloned. ( The first animal to be cloned was a gold fish achieved by a Chinese scientist)  Six years prior to this they had produced an ewe genetically modified with a human gene to secrete a protein called alpha-1-antitrypsin (rAAT). The drug was extracted from the milk of the animal and was used to treat cystic fibrosis which caused emphysema.  PPL Therapeutics Ltd. In conjunction with the Scottish  opened up a 50 ha sheep farm in New Zealand close to Rotorua. By 1999 it had thousands of transgenic sheep producing the human protein.

 Fig.3. 'Tracy' the sheep had a human gene to produce a valuable protein in her milk.   

Although the PPL Therapeutics NZ. Ltd had to pull the plug in 2004, due to various internal and external causes and incinerate thousands of live animals the venture could be considered to have struck oil.  . Dairy farmers have bred cows for hundreds of years and produced high yielding and disease free varieties. Yet they have not been able to get special breeds  to produce specific formulas required by the customers. The different varieties of milk available in a super market such as , Juniors, high fat low fat and specials for the elderly are all formulated or extracted from the normal milk from the cows. Assuming the producers maintain a high standard in keeping with their labels the cost of production should be fairly high. The best alternative would be to breed cows to generate different varieties.

Can it be done? Theoretically, the answer is an emphatic yes. It is now not beyond genetic technology to produce transgenic cows by lending some human genes. 

Fig.4.  Herman the bull has human genes.

 A biotech. company in US has engineered a bull named 'Herman', It is equipped with human genes capable of production lactoferrin.It is their intention to build a herd of transgenic cows that will give a milk identical to  breast milk.

GenPharm, a biotech. company in US has already engineered a bull named 'Herman' with human genes. Its female progeny would be capable of producing a milk containing lactoferrin along with  a few other essential qualities to match the breast milk.

Human beings generally consume the flesh of the most other species along with other carnivores and omnivores. It is not likely for any human of today to be cannibalistic. If any progeny from the  Herman’s brood are butchered for meat, what we would consume will not be 100% beef, but a kind of flesh containing a percentage of human meat. Some of us would end up as cannibals unknowingly.


Beef is not the only food that will possess human genes. The next in line are the  fish and the pigs. Pig farmers do not rear pigs for milk. What they yield are pork, ham and bacon.

Fig.5. Engineered to produce organs for human patients.

There is another side to the story.  Until Prof. Christian Bernard performed the miracle of a heart transplant, hardly anybody thought such a feat is within the scope of mortals. The next miracle is going to be ‘xenotransplantation’: which means transplanting animal organs in human bodies. Today all over the world there are many patients lying in a gruesome state waiting for organs such as kidneys and the precious fluid blood. The researchers have found the ‘swine’ as the ideal mammal for the purpose.

Kent Atkinson had this to report in the 13.12.05

“Using pig and other animal parts for human transplants moved a step closer today after the Government's biotech ethics advisor gave the green light. The Bioethics Council opened the way for transplants of animal tissue into humans to be resumed ……….. Six New Zealanders would already qualify for such registration -- they were injected with pig islet cells in 1996 as part of a clinical trial of treatment for diabetes.”

DNX Corp of NJ.  has engineered three pigs with human haemoglobin circulating in their blood streams,  Mr. Logan announced  the following advantages of pig-blood over that taken from human donors:

 a.     It would be free of viruses such as the AIDS and hepatitis viruses

 b.     It  could be given  without blood type matching

 c.     Pigs will be able to produce haemoglobin in large volumes and at lower cost


What is your opinion of Transgenic animals now? Should we fund them or ban them?

If you wish to avoid being a cannibal the best alternative would be to become a vegetarian. If you read this you may have to have second thoughts even about that. An attempt to genetically engineer tobacco plants to produce human hemoglobin is being made by Biosource Genetics Corp. in Vacaville, Calif.  Other companies in the field include Quest Biotechnology Inc. in Detroit, which has licensed its hemoglobin technology to four companies:

As long as human genes entering such plants as tobacco would not be a worry to vegetarians, but what happens when researchers apply the same techniques on paddy, maize and other crops such as grapes, apples and cabbages?


Pig-to-man Blood Transfusion May Be Just the Start

December 18, 2000
The New York Post


Dr. Dhaniram Baruah, a London surgeon, injected more than half a pint of the blood into a man suffering from severe anemia.Baruah, 50, says he has developed a method of preventing the rejection of animal tissue by the human body, and hopes to continue research on animal donors in human medicine.The experimental transfusion took place when critically ill laborer Hussan Ali, 22, agreed to receive the blood last month in a last-ditch effort to save his life.Almost four weeks later, Ali - who has an undisclosed illness - is alive and has been discharged from the hospital.Test results confirm Ali has "nonhuman" blood cells circulating in his body.

Baruah believes he is on the way to a medical breakthrough that will provide a plentiful supply of blood for operations - particularly in underdeveloped countries where human blood donors are in short supply.Pig blood might be used in the treatment of AIDS, hemophilia and other blood disorders, he claims."I believe I can use the same technique to make donor bone-marrow cells compatible from unmatched donors. It will be of great value in treating leukemia patients," he told The Sunday Times in Britain.

He says the key is an "antigen-suppression agent," necessary to prevent the body from rejecting tissue from another organism.But he won't discuss details because he is planning to patent his discovery.Animal-to-human transplants have been controversial because of the seemingly insurmountable problem of new, untreatable diseases getting into humans from transplanted animal organs.Three years ago, Baruah caused outrage in India when he performed the world's first pig-to-human transplant.The patient regained consciousness after receiving the heart and lungs of a pig, but died a week later, apparently from acute infection.

The surgeon spent more than a month in jail before prosecutors dropped charges that he had contravened India's organ-transplant act