GMO’s: Harder, Better, Faster, Stronger

As the world’s population increases the demand for sustainable and efficient agriculture has grown and many companies are competing to make ever better genetically modified crops.

 

Many genetically modified organisms (GMOs) are being improved in ways that have just been discovered. Older GMOs exist and have for some time, but the methods used to make the older generation of GMOs had many limits on what advantaged could be added to crops. Research has found programmable DNA binding proteins such as ZFP, TALEN, and CRISPR/Cas that allow for the input of specific DNA sequences in specific spots on chromosomes. These new techniques allow scientist to create widely improved crops and even add in totally new attributes that do not belong to those crops.

 

These newer crops can be changed in ways that were impossible by the older methods, creating crops that are disease resistant, protected from pests, and do not require as much sun. These are just three of many attributes that are closely targeted by scientist. There have also been some sensational news reports about odd but useful modifications being made in some places, and not all are related to this research. In Japan watermelons are being grown in square shaped containers, originally to decrease later shipping costs of the fruit. These watermelons are now highly prized and sold for more than regular watermelons because of this new shape. It is possible that the future holds GMOs created to not only be better for growing but also more ascetically pleasing.

 

The advantage to these techniques is that they are some of the only methods that have real potential to raise food production to the levels needed to meet demand. Crops will not spoil as fast and are better in every way than tradition crops, or even older GMOs.

 

Some of the disadvantages include patent protection on GMOs by the companies that make them, which are used to artificially increase seed prices for farmers and stop these great crops from ruining company profit margins. But while good for the company the prices can have negative impact on medium sized farms that have a hard time selling their produce at higher prices. There has also been some concern about lack of diversity in the crops. The lack of diversity is both in types of crops grown and the diversity among a single crop. With natural breeding no longer being a factor crops do not have the range of immunity to diseases that are seen in the wild nor the lucky mutations that prove advantageous in the face of adversity. As certain crops are more heavily modified and profitable than others the diversity of what is grown to meet the food supply will decrease. We have already seen evidence of this by the decreasing numbers of apple varieties available at super markets. Having diverse food sources helps grow food security since it is unlikely that that any one mishap will be able to ruin every type of crop. Decreased diversity will allow one type of mold, bacteria, or natural disaster to disproportionally affect the food supply if there are only a few types of crops being grown.

 

Let me know what you think about GMO’s. Are they good, great, or horrible for the future? Are the conspiracy theorists right about them being unhealthy?

 

Precision genetic modifications: a new era in molecular biology and crop improvement

By: Franziska Fichtner, Reynel Urrea Castellanos, Bekir Ülker

DOI 10.1007/s00425-014-2029-y

 

Nanotechnology vs. HIV: The fight of the future

Most HIV treatments focus on the use of anti-retroviral drugs to decrease the amount of virus in the body to almost undetectable levels. These drugs frequently target the enzymes that HIV needs to replicate itself inside of cells in order to slow replication and decrease viral load.

HIV has a high rate of mutation compared to a mammal such as ourselves, and it will often mutate in enough to develop resistance to certain anti-retroviral drugs. Mutations in viral RNA that change the proteins produced in cells or mutations that change how HIV enter the cell can lead to drug resistance. In order to slow down the development of drug resistance many patients are put on combination therapies, which use multiple medications to keep the viral load in a person low and stop virus replication at many steps.

With combination therapies the development rate of resistance is slowed, however there are worries that viruses will still mutate fast enough to outpace our ability to develop new drugs. As HIV drug resistance becomes more common it is likely that this will eventually be the case. New treatments that attack HIV in radically different ways are being developed to hopefully find a long lasting and safe treatment for HIV. One such treatment involves the use of RNAi or RNA interference. This involves using microRNA and siRNA to target conserved genes in HIV with little mutation, binding and destroying the viral mRNA to stop production of the virus effectively and efficiently. The only problem with this research is delivering the RNA necessary for interference to every cell that needs it.

Attempts have been made to create viral vectors to do this, however the results were often underwhelming and at times dangerous. This brings me to nanotechnology. The latest research is delving into multiple types of nanotechnology to safely deliver RNA to targeted cells. This technology includes artificial liposomes, polymeric nanoparticles, dendrimers, and inorganic nanoparticles. Finding something that can deliver the RNA will allow for advances in many medications and may help to put a major dent in the spread of HIV worldwide.

Let me know what you think. Will nanotechnology be able to advance fast enough to find a transport system for RNAi? If you want to do more research on this topic you can start on the article below.

Nanotechnology Approaches for the Delivery of Exogenous siRNA for HIV Therapy

Simeon K. Adesina and Emmanuel O. Akala

Mol. Pharmaceutics

DOI: 10.1021/acs.molpharmaceut.5b00335

http://pubs.acs.org.ezproxy.shsu.edu/doi/10.1021/acs.molpharmaceut.5b00335

The evolution of disease

Some diseases are caused by a person’s genetics. In many cases diseases can be predicted by looking at DNA for specific genes that predispose someone to a disease. Having said that DNA is also connected to evolution, in that genomes that confer an advantage to a person will increase the probability of that person reproducing. Over time well adapted and healthy genomes will become prominent in a species.

            Why is it that so many diseases can be passed genetically when the theory of evolution claims that only the fittest will survive? Would that not mean that genetic based diseases should have died out long before the modern day? In truth it is much more complicated than that and there are many factors at play. Genetic diseases could always occur in a later generation through mutation in reproductive cells, being passed in that way. Or a series of other advantages will allow someone to still be fit enough to pass along a disease. Some diseases hide as recessive traits, only appearing when two carriers of the recessive trait mate.

            Then there are some diseases that are relics of a different time. Some diseases are still prevalent because they conferred an advantage in the past, and even with the significant side effects of a disease the advantage proved invaluable. Once this advantage was selected for it became prevalent in certain populations over time. Fast forward generations later and people still have these diseases in different circumstances that no longer provide a benefit, yet medical science has advanced enough that even without the advantage the disease will still be a permanent part of the population.

            One interesting example is Type 1 diabetes. People born with Type 1 diabetes have an autoimmune response that prevents them from producing enough insulin. Without insulin the person will have unusually high amounts of glucose in the blood. It has been found that Type 1 diabetes is most prevalent in northern Europeans, occurring at a frequency that is more common than random chance would suggest possible, showing signs of having been selected for in that area in the past. What advantage would that give? As it turns out high amounts of glucose in blood will depress the freezing point, increasing the tolerance for cold in humans. In the past minor ice ages and unseasonably cold weather would kill those unprepared for it, selecting those with Type 1 diabetes because of their tolerance for the cold. Trading a healthy amount of insulin for this advantage proved invaluable in the past and modern northern Europeans still suffer today as a result.

This leaves an interesting new avenue for understanding the epidemiology of disease. People with sickle cell trait have a higher resistance to malaria because of their malformed hemoglobin. Iron deficiency improves the chances of surviving infection by Yersinia Pestis, the bacteria that causes the plague, better known as the Black Death.

Finding how many diseases conferred an advantage in the past would also lead to better understanding of what diseases may give advantages in the modern day. A more holistic view of disease could also lead to new treatment ideas as well.

Want to learn more? I have an article about the prevalence of Type 1 diabetes listed below. A well written book on the subject of advantageous diseases that I have read in the past is also below. The book is much more interesting than any textbook and I highly recommend it for some casual reading.

For further reading please see:

The sweet thing about Type 1 diabetes: A cryoprotective evolutionary adaptation

By: S. Moalema, K.B. Storeyb, M.E. Percyc, M.C. Perose, D.P. Perl

http://www.sciencedirect.com.ezproxy.shsu.edu/science/article/pii/S030698770500054X

A more in depth novel on the subject:

Survival of the sickest: A medical maverick discovers why we need disease

By: Sharon Moelem

Why Questions in Science are so Important: Studies on Adaptive Sex Ratios

For the first addition to my blog I would like to talk about the importance of peer review. Though it is not strictly speaking molecular biology, it is important to every field of science and is gives people a good reason to blog and read about scientific discovery. I have provided an example of how peer review can help to evolve research on a subject.

For some time, scientists have provided evidence for or against the idea that malnutrition and stress lead to a change in the sex ratio at birth. For those of you not so familiar with the subject humans naturally have slightly more male births, usually around 106 male births for every 100 female births. It had been postulated in 1973 by biologist Robert Trivers and computer scientist Dan Willard that females in good condition, whether it was in regards to physical hunger or economic class, would always have a sex ratio skewed in favor of males. This of course meant that females that suffered from hunger or were in a disadvantaged economic class would have a more balanced sex ratio at birth, or in extreme cases even more female than male births.

This was controversial and many people disagreed with them, however scientific studies could not definitively prove or disprove the theory. The debate on this idea has persisted to this current day, with many researchers publishing on both sides of an argument, often citing papers of the opposing side in order to point out some flaw in a previous method. I have provided four such papers at the end of this post if you would like to read more on the subject. The first, “Maternal undernutrition and the sex ratio at birth in Ethiopia: evidence from a national sample” finds that there is a slight correlation between hunger and birth but it is not definitive and to points out that previous papers that say otherwise were statistical aberrations. The next two actually study the same famine, from the Great Leap Forward in China, in order to disprove then prove the connection between hunger and sex ratio. The last is a paper detailing how poor experimentation, observation, and calculation has allowed the debate on the subject to persist when it should be long over.

Most articles published now accept the connection as fact. Without a peer review process would the debate have even occurred? Or would Willard and Trivers been dismissed as crackpot theorists in 1973? My challenge to you is to review the literature and let me know what you think. Is there enough evidence to definitely say starvation can cause more female births? Is it appropriate to call out past researchers on flawed methodology?

·       Maternal undernutrition and the sex ratio at birth in Ethiopia: evidence from a national sample

By: Aryeh D. Stein, Paul G. Barnett, Daniel W. Sellen (2004)

http://rspb.royalsocietypublishing.org.ezproxy.shsu.edu/content/271/Suppl_3/S37

·       Could changes in reported sex ratios at birth during and after China’s 1958-1961 famine support the adaptive sex ratio adjustment hypothesis?

By: Zhongwei Zhao, Yuan Zhu, Anna Reimondos (2013)

http://search.proquest.com.ezproxy.shsu.edu/docview/1501334626?pq-origsite=gscholar

·       Malnutrition, Sex Ratio, and Selection A Study Based on the Great Leap Forward Famine

By: Shige Song (2014)

http://eds.a.ebscohost.com.ezproxy.shsu.edu/eds/pdfviewer/pdfviewer?sid=7be5eac1-8c2e-4a12-b235-2c56e4e06a83%40sessionmgr4006&vid=6&hid=4211

·       Privation, stress, and human sex ratio at birth

By: Shige Song (2015)

http://www.sciencedirect.com.ezproxy.shsu.edu/science/article/pii/S0378378215002133?