Genetics

It was in 1996 the world woke up to the news of a sheep named Dolly created through a technique called cloning. Dolly was a carbon copy of another sheep and this started a debate on should scientists be acting like God and producing animals and humans on order.

Cloning is done by removal of DNA from an ovum and replacing it with the DNA of an adult animal. The fertilized ovum is implanted in a womb and an identical or clone animal can be produced. However, the technique is fraught with risks. The cloned animals have been known to carry genetic disorders and have a comparatively short lifespans.

Not many people know that Dolly was not the first animal to have been cloned by scientists. Way back in 1958, scientist John Gurdon claimed to have cloned a frog by using intact nuclei from somatic cells of a Xenopus tadpole. In 1963, Chinese embryologist Tong Dizhou created the first fish clone by inserting the DNA from a male Asian carp into the egg of a female Asian carp. Dizhou went on to create the first interspecies carp clone by inserting Asian carp DNA into a European crucian carp in 1973. In 1986, a mouse named Masha became the first mammal to be cloned using embryo cell.

However, Dolly is still regarded as the most significant achievement in the history of cloning because she was the first mammal to have been cloned using adult cells. Before her, cells extracted from an embryo were being used to create a clone. The success of the Dolly experiment also resulted in a fierce competition among various research groups who started cloning one animal after another.

Scientists at the University of Hawaii created Cumulina, the first mouse clone using adult cells, within one year of Dolly’s birth in 1997.[ad#co-1]

The first cloned calf was also born in the same year and later kept at Minnesota Zoo Education Center. In 1999, Dr Xiangzhong (Jerry) Yang cloned a Holstein heifer named Amy by using ear skin cells from a high-merit cow named Aspen at the University of Connecticut. He followed it up by three additional clones, Betty, Cathy and Daisy in the same year.

The year 1999 saw birth of Second Chance, a Brahman bull which was cloned from a celebrity bull Chance at the Texas A&M University. The research centre was also successful in cloning a Black Angus bull named 86 Squared 15 using cells from his donor, Bull 86, which were frozen in 2000. Just like its parent, the cloned bull also exhibited natural resistance to tuberculosis, brucellosis, and other diseases which can be transmitted to meat.

Five Scottish piglets were created using cloning technique in 2000. In 2001, cloning was done to save Gaur, an endangered species of wild cattle. It was born from a surrogate domestic cow mother at the Trans Ova Genetics in Sioux Center, Iowa, USA. However, the clone died within two days.

The year 2001 saw intensified activity in the field of cloning with birth of two female jersey cows Millie and Emma at the University of Tennessee. They were the first cows to be produced using standard cell-culturing techniques.

In the same year a cat called CopyCat was cloned at Texas A&M University. Though the DNAs of both the clone and the host were same, they had different personalities. Around 10 more Jersey cows were cloned at the University of Tennessee in 2002 while the first commercially cloned cat, Little Nicky, was created by Genetic Savings & Clone in 2004.

In 2003, a Boer goat was cloned at Texas A&M University. In the same year, three male mules were cloned for the first time while a rabbit was also cloned in France.

The year also saw the birth of a first cloned deer named Dewey at Texas A&M University while in 2005 South Korean scientist Hwang Woo-Suk cloned the first dog, Snuppy, an afghan hound. South Korean scientists went on to clone sniffer dogs.

Anatolian Grey bull called Efe was cloned in Turkey along with world’s first buffalo calf through the “hand guided cloning technique” in the year 2009. Next year, the first Spanish fighting bull was cloned by Spanish scientists.

The cloning experiments on animals are still on around the world while there are some unverified claims of human cloning too.[ad#afterpost]

Can you roll your tongue into shape of a test tube? Do you get dry ear wax? Do you have cleft chin? Can you wiggle your ears? When you clasp your hands which thumb lands up on the top? These questions may seem innocuous and unwarranted but a whole lot of researchers are scratching their heads on these puzzles which many believe is linked to genetics.

So can you really roll your tongue into shape of a tube? Not many people can but then they do have friends who can and this difference some researchers say is because of genetics. Biology students are taught that tongue rolling is the simplest way to explain inherited genes. Those who can roll their tongues have inherited the gene from their tongue-rolling parents while those who can’t also have parents who can’t roll their tongues. You have got your genes from your parents and even if one of the parents has the tongue-rolling gene, you will be able to roll your tongue.

It’s not so easy to explain

The explanation is not as simple as it is made it out to be and your biology teacher might be wrong after all because there are people who can roll their tongues while their parents can’t. Another research study done by Matlock in 1952 concluded that identical twins don’t always share the tongue-rolling trait. Identical twins are known to have identical DNAs and hence should also share the ability to roll the tongue if they have same genes.  In 1975, another researcher demonstrated that identical twins are no more likely to share tongue-rolling than are fraternal twins. This gives birth to the idea that environment is also a major factor. Both the twins might be having the gene but it is not expressed in one of them due to absence of an environmental trigger.

The environmental trigger theory has also found takers in several other conditions like autoimmune disorders. People are known to be predisposed to them but these disorders are manifested in only those who encounter particular environmental triggers stress, pollution or specific disorders.[ad#co-1]

Another theory regarding tongue rolling is that there might be another gene called modifier gene which is controlling the expression of tongue rolling gene. So there can be parents who possess the gene to roll their tongues but still they can’t roll them because the modifier gene in them is off. Now their child can have the ability to roll the tongue if they modifier gene is not passed on.

All these explanations may seem confusing but that’s not the end of the whole story. Tomorrow some new research may prove that all the above propositions are wrong and there is some new factor that defines tongue rolling. Meanwhile, surveys done by biologists have put forth interesting data related to tongue rolling. It was found that in Spain 67 per cent of females can roll their tongues compared to just 64 per cent of the male population. However, Spanish men are better at wiggling their ears. Around 20 per cent of them can wiggle their ears as compared to 10 per cent of women. Another Iranian researcher found that north England does not have many people who can roll their tongues and this, he believes, is because of genetic intermingling with the Scandinavians.

Whatever the final verdict be, it’s clear that if you can roll your tongue, genetics are involved in this ability of yours. However, to what extent the power of genetics works in this scenario is not yet known. So, the picture is out but the contours are still being finalized.[ad#afterpost]

In the movie “The Sixth Day”, a clone of Adam Gibson (Arnold Schwarzenegger) takes over his family and professional role forcing the original character to prove his authenticity in the year 2015.

The movie could not be far from reality especially when experiments to produce human clones are being done clandestinely across the globe.

Cloning debate gained momentum since Dolly, the first cloned mammal, walked over the earth in 1996. The birth of Dolly opened the possibility that humans can be also be cloned using the same technique. Today, scientific cloning is yet to go mainstream mainly because it’s a difficult and expensive procedure and till now the clones produced have not been able to live long enough.

While animal cloning is quite acceptable in the society, we are yet to accept the fact that some time in future human clones will be greeting us in neighborhood parks.

Human cloning is possible through various methods. Embryo cloning, one of the methods, involves production of identical twins artificially. A few cells extracted from a fertilized embryo can be induced to develop into a duplicate embryo having DNA identical to its parent embryo. This technique has been used successfully on animals.

Another method is through removal of DNA from an ovum and replacing it with the DNA of an adult. The fertilized ovum is implanted in a womb and an identical or human clone can be produced. However, studies done on animals show that this technique can result in severe genetic defects in the newborn. Due to these side effects, this technique is banned in several countries but an Italian embryologist claimed to have developed a human clone through this procedure.

Several ethical issues of human cloning crop up through the years. Some people would like to have a clone to have a biological insurance to extract organs from in case their original ones fail or damaged. In this scenario, the existence of a clone just to save the original human being or to act as a replacement for him strongly questions human morality.

While a human clone’s right to identity is jeopardized, questions are raised on his right to inheritance, choice of a life partner, and other crucial life matters.

The safety of cloned humans is also questioned. While most attempts to clone mammals have failed, several of the clones born suffer from debilitating conditions and die prematurely. Moreover, we still don’t know how cloning impacts the brain and other vital organs in the body.

Therapeutic cloning, another technique, differs from reproductive cloning in a way that no offspring is given birth to. Only stem cells are extracted from the pre-embryo for the purpose of developing organs or tissues that can replace the damaged organs of the original DNA donor. The process eliminates the need to wait for the right donor and since the DNA is exactly the same, there are no complications in organ transplantation..

However, many decry such a procedure since the human embryo is destroyed in the extraction of stem cells. They feel that since embryo is equivalent to a human being, he should have rights equal to those of normal humans and killing him just to save the life of another person is simply unjust.

The stem cell proponents, however, claim that the stage at which the stem cells are being extracted is a very nascent stage and the embryo does not have brain to have awareness of the self and also lacks a thought process. They feel it can only be termed as human when it’s aware of the environment and has sensory capabilities, organs and limbs.

Time will tell whether humans are going to accept human cloning technology or not. But many scientists are unstoppable in developing perfect techniques on human cloning and stem cell production.

[ad#afterpost]

There is no love more sincere than the love for food. Food is  a uniting factor among different cultures since everybody likes to taste and enjoy exotic cuisines from around the world. This is also one of the reasons why the issue of genetically modified (GM) food is generating intense debate because we are what we eat. GM food includes crops, fruits and vegetables which are created by combining quality genes of various species and hence have better nutritional and productive value. The difference between this technique and traditional breeding is that latter occurs only between related species and hence is safe whereas there is no final word on safety of mixing genes of unrelated species.

Both sides of GM food debate are equally vociferous in expressing their opinions. While the pro lobby talks about how the GM crop can give a larger and better yield even in inhabitable conditions, the critics talk about risk to health and environment due to genetic alterations and exploitation of the poor by food corporates. Here we have a deeper look at the issue.

Advantages of Genetically Modified Food

Supporters of GM food crops are mostly relying on scientific data claiming that these crops yield much larger quantity and hence can be the solution to the problem of world hunger. The ability of GM crops to be cultivated even in areas with poor soil and harsh weather conditions is one of the advantages of genetically modified food. Another plus point is that the food produced is higher in nutritional value and can also taste better than the traditional variety. GM crops have inbuilt resistance against pests, insects and diseases allowing them to produce higher yield. The proponents are also claiming that genetic modification can even make certain food free of common allergies. This can be done by removing the genes that express the allergens or substances that trigger allergic reactions.

The GM foods are also capable of staying ripe for long hence there is lesser problem of spoilage. This can be done by adding a gene in the crop that expresses an organic compound that will extend the shelf life of the food.

[ad#728-90 after post]

Disadvantages of Genetically Modified Food

While the pros of GM food may seem rewarding, the critics claim that they don’t hold water. First of all, they counter the technique itself by putting forth the argument that scientists still don’t know much about the genetics GM crops. They may identify quality genes but where to introduce them so as not to disturb the natural expression is still unclear. In fact, this lack of knowledge can lead to faulty interventions and irrepressible side effects. Traditional breeding has natural checks and balances due to breeding between related species but these are missing in GM food crops.

The hope that GM food can be an answer to the world hunger is another faux pause because they claim that millions of people sleep with empty stomach not because of lack of food but because of improper distribution. Millions of tons of food are wasted every month around the world because they do not reach the needy. Financial, infrastructural and political reasons rather than less production are responsible for the large number of hungry people across the globe.

The GM food may be having inbuilt resistance to common pests and insects but these organisms are known to mutate according to changes in their environment for survival. Thus, disease-resistant crops will only give rise to superbugs which will be more difficult to destroy.

Another big issue with GM crops is that they cross-pollinate with nearby normal crops and lead to ecological issues. Furthermore, if GM crops contain vaccines and antibiotics, human health is in peril as it would contribute to the development of resistance genes to human viruses and bacteria that we normally kill using vaccines and antibiotics.

Opponents assert that GM crops are patented by big biotechnology corporations that make sure that the harvested grains/fruits are not viable source of seeds to force farmers to buy costly seeds every time they want to cultivate the land.

Tests to validate the risks of GM crops are very expensive that most corporations avoid testing each and every food item. This increases the chances of unsafe food getting served to people.

[ad#afterpost]