Genetic Engineering
By: Uriel Martinez
Should Genetic Engineering Be Permitted?
Drought Tolerant Seeds
Companies have been trying to produce drought tolerant corn for years to increase the amount of produced per year. The problem is that you cannot just insert or eradicate certain genes because they all work together and you have to experiment on how one alteration will affect the seed as a whole.
Many farmers are trying out these seeds and some have very high hopes that it will become a major success. On the other hand, some producers say that even though there has been yield increases of 15%, they "are not making a specific claim" (Piller) and are telling farmers not to overreact.
Synthetic DNA
DNA and RNA are formed by deoxyribose and ribose which are sugar molecules and they connect to phosphates to make the double helix structure so the 4 nucleotide bases (A, C, G, and T) "attach to to make a chain." (Brown) These nucleotides are the components that contain the genetic information.
To show that XNAs could pass along genetic information, researchers engineered enzymes to read the information stored within the XNAs and "write it onto DNA. After making a bunch of copies of that DNA, they used the enzymes to write those copies back to XNAs." (Brown) This has shown that XNAs can pass down information and they are "capable of evolution -- in this case, the ability to bind to certain protiens." (Brown)
DNA and RNA are very hard to work with which is why XNA might be able to show us about them in the lab and in producing medicine. In addition, scientists say that life on Earth might have started even simpler than RNA in forms similar to XNAs, like TNA. Who knows how many possibilities there are in the future of XNAs.
Reversing Age-Related Degeneration in Mice
"'These mice were equivalent to 80-year-old humans and were about to pass away,' says Ronald DePinho, co-author of the paper and a scientist at Dana-Farber Cancer Institute in Boston. After the experiment, 'they were the physiological equivalent of young adults.'" (Naik)
In an experiment, mice were "altered so they would age prematurely" (Naik) and there was the possibility of cancer although there were no signs of any tumors. This was because the team had engineered the mice to have short telomeres. A telomerase is an enzyme that holds a small bit of DNA and telomeres are the parts at the end of chromosomes that prevent the DNA within the chromosome to unravel. When cells divide, telomeres naturally become shorter and as you age, they become shorter. Because of these "short, dysfunctional telomeres" (Naik) the mice had a long range of age-related problems such as damaged intestines and shrunken brains. Researchers then wondered if they could produce a drug that could reverse these effects on the mice.
As it turns out, they produced an "estrogen based drug" (Naik) that turns on the animal's TERT gene so the mice would be able to grow longer telomeres. The drug was given as a pellet and another non-active pellet was given to the control group.
"A month later, the treated mice showed surprising signs of rejuvenation. Overall, their telomeres had lengthened and the levels of telomerase had increased. This woke up the dormant brain stem cells, producing new neurons. The spleen, testes and brain grew in size." (Niak)
"In addition, key organs started to function better. The treated mice regained their sense of smell. The male animals' once-depleted testes produced new sperm cells, and their mates gave birth to larger litters. The treated animals went on to have a typical lifespan, though they didn't live longer than normal mice." (Niak)
The only worry is cancer. 90% of human cancers are able to turn on the telomerase gene and divide uncontrollably. Either way, turning on this gene on may be helpful if it is for "controlled periods of time." (Naik)
"Statistically, people with longer telomeres in their blood cells have an increased number of healthy years beyond the age of 60, Dr. DePinho said. And those over 60 with the shortest telomeres have higher rates of diabetes, cardiovascular disease and Alzheimer's."
Should Genetic Engineering Be Permitted?
Bibliography
Naik, Gautam. "Aging Ills Reversed in Mice." Wall Street Journal. 29 Nov. 2010: A.3. SIRS Issues Researcher. Web. 18 Jun. 2014.
Piller, Dan. "Drought-Tolerant Seeds on Way." USA TODAY. 31 Aug. 2012: p. B.3. SIRS Issues Researcher. Web. 18 Jun. 2014.