CRISPR/Cas9: A Genetic Analysis

More than 50% of the world’s population lives in an area where Malaria is common. The first signs of malaria are fevers, chills, joint pain, vomiting, and anemia, and can lead to a coma or death. Scientist JBS Haldane once suggested that people with sickle cell anemia or thalassemia were naturally resistant to P. Falciparum, the malarial disease. G6PD is an even better naturally evolved protection against malaria. Researchers who studied the relationship of G6PD deficiency and malaria found that children with the G6PD-A- mutation had a resistance twice as strong as normal children to P. Falciparum. That’s because Malaria, like many other diseases, prefer “normal” healthy red blood cells rather than G6PD-deficient blood cells to multiply. Malaria is a delicate virus, and can only thrive is clean red blood cells. The G6PD deficient cells are not only less hospitable to the virus but die early which may disrupt the virus’s lifestyle. At one point in time people recognized that eating fava beans would reduce their body’s hospitability to Malaria, and thus evolved Favism disease which continues to serve the same purpose today. People who are only partially deficient (women) are much better off because not only do they get the malarial protection, but they also can ingest fava beans and medicine safely. This is why people of African and Mediterranean descent continue to develop Favism

Passing genetic code does not always have to be used to help a species as genetic engineering can be used to hinder or kill one. Dr. Esvelt who is the leader of the Sculpting Evolution group wishes to modify malaria-carrying mosquitoes. The idea is to control the mosquito population with an engineered population, and giving that

Vector-borne disease organisms are important factors that promote the evolutionary increases of virulence. Disease organisms transmitted through vectors like mosquitoes, tend to be much more damaging than diseases that are simply transmitted by people coughing or sneezing (droplet transmission). In vector- borne diseases immobilizing the host does not prevent transmission, but it might even enhance it. Experimental studies indicate that mosquitoes are better able to bite a laboratory animal when it is sick with a vector-borne disease such as malaria than when it is healthy

A gene editing method called CRISPR, Science’s 2015 Breakthrough of the Year, is an easy and inexpensive way to cause the “DNA-cutting enzyme” to cut out specific parts of the DNA strand, therefore changing the genetic composition of an organism. Another way to use the CRISPR is to use it to deliver regulatory factors to successfully turn genes on or off and any level in between, which can help save lives by turning off deadly genes. CRISPR is currently being used for biomedical purposes, such as repairing genetic defects or creating tissue-based treatments. This genetic editing method could be used and is being used to change the very animals and plants that we know today by creating allergen-free peanuts or virus resisting pigs.

Technology is advancing at a rate today that would leave people from as recently as one decade ago in awe. Among the groundbreaking developments is genetic engineering, which is when scientists modify the genetic makeup of an organism, whether it be altering an animal, plant, or other living thing. Genetic engineering can do many wondrous things for today’s society, such as make crops grow in more adverse conditions, and rid humans of certain malformations and medical conditions. According to Sam VanOrman, another modification that should be added to that list is genetically modified mosquitos; however, I respectfully disagree.

Mosquitoes can transmit a bigger number of illnesses than other variants of arthropods and have an impact on a large number of human population all throughout the world. WHO has declared that mosquitoes are the “public enemy number one” (Geneva, 1996).

and possibly eliminate the disease. This biotechnology makes it possible for more people to live the lives

Between 1998-2004, the malaria cases in Panama quadrupled. And globally, the malaria death toll has grown inescapably since 1981. In 1995, Europe suffered 90,000 cases of malaria. Today, eight times more malaria patients arrive at the clinics and hospitals across Europe than they did in the 1970’s. Mosquitoes infect between 250 million and 500 million people with malaria every year and close to 1 million perish. Human beings have suffered the disease for more than 500,000 years. This plague is very deadly.

The endonuclease Cas9 is the core multifunctional protein of the CRISPR-Cas9 system. Two nuclease domains: HNH (39) and RuvC-like (40), within the Streptococcus pyogenes Cas9 (SpCas9) protein conduct the function of cleaving DNA strands. Studies have confirmed that the tracrRNA: crRNA duplex structure will lead to the sequence-specific DNA cleavage (41). PAM short sequence facilitates crRNA to recognize the targeted DNA sequence (42). Cas9 protein cuts the specific DNA strand that is complementary to the 20bp crRNA sequence via HNH domain; on the other hand, the SpCas9 RuvC-like domain cleaves the opposite targeted DNA strand (42) (Fig. 4). Mutating either of these two nucleases domains of SpCas9 will introduce a single-stranded DNA nick, while mutating both HNH and RuvC-like domains will transform SpCas9 into a RNA-guided DNA binding protein (42). X-ray crystallography and has confirm that endonuclease Cas9 undergoes a series of conformational rearrangements when it binds to the guide RNA and target DNA (55).

Since the implications of CRISPR/Cas9 technologies were discovered, research has mostly gone in two different directions. Bioengineers and pathologists are starting to experiment with using CRISPR as treatments to hereditary diseases with the hope that someday, they could cure certain genetic diseases. Another application currently being experimented with is using CRISPR to genetically modify organisms for various purposes.

Animal species: Mosquitoes are a slender long-legged fly with aquatic larvae. The bite of the bloodsucking female can transmit a number of serious diseases including malaria and elephantiasis. More specifically in this case study of natural slection, both the Anopheles gamblae and the Anopheles stephensi are the main vector of malaria in India (Anopheles stephensi) and Africa (Anopheles gamblae).

In recent years, an astonishing technique has been rapidly developed that has changed the way we look at genetics, and that holds the potential to change the future of our world. This system, known as clustered regularly interspaced short palindromic repeat with an associated protein (ie. CRISPR-cas9), has evolved in the past 30 years from what was called a ”curious sequences of unknown biological function”, into a promising genome editing tool.

In this TED talk, biologist and geneticist, Jennifer Douda, presents a way to edit our DNA with the use of CRISPR technology. This technology allows scientists to change the DNA within our cells that could ultimately allow scientists to cure various genetic disease such as sickle cell anemia, Huntington’s disease and cystic fibrosis etc. The way this technology works is that the Cas9 protein seeks foreign DNA, and precisely cuts that DNA out and eventually degrades it. After the mutated DNA is removed from the double helix, the cells detect the broken DNA double helix, and repairs it by pasting its ends together via a tiny change within the sequence of the DNA, or cells may simply introduce a new sequence of DNA at the site of the break,

Due to the factor of climate, the transmission rates thrive in regions when the conditions are right. For example Africa has an average temperature of 33o C, this is the ideal temperature for mosquitos and this causes a high transmission rate, relating to the concentrated pattern that follows the equator. There are many factors which prevents malaria from occurring and from that, transmission rates do not take place. In the subtropical regions, where malaria is most susceptible, mosquitos have to alter themselves to different conditions in order to bypass the obstacles where the transmission cycle will not occur. Firstly, transmission will not occur during cooler seasons such as winter as it will be less prevalent and is generally seasonal. Also deserts- excluding oases, are not at risk as the regions of Sahara and Kalahari become too dry, and also there is insufficient number of moisture which eliminates the survival of the mosquitos. Another Alternative involves countries where transmission have been intervallic through eradication. This is evident in moderate temperature areas such as Eastern Europe and the United States. The need for economic development and public health care have been met as there has been a complete eradication in malaria. The majority of countries that are at a low risk of getting malaria, are still vulnerable but with the introduction of healthcare the chances are low. This is evident when referring to malaria at a global scale as none of these

Malaria is considered the most important vector-borne infectious disease in the world, which is caused by a species of the Plasmodium parasite, and transmitted by female Anopheles spp mosquitoes.2,10,12