BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: Malaria

Let’s Talk About Malaria

Let’s Talk About Malaria

A small mosquito landing on a human finger.

 

Did you know, that the World Health Organization estimates that roughly 438,000 people die annually due to Malaria? Well, now you do know that unfortunate fact. But – did you know that the total number of people affected by malaria is only growing? In reality, those don’t matter, what does matter is what we are going to do now to combat the issue and CRISPR/cas9 might be the answer. In order to better understand the issue of Malaria and the resolution of utilizing CRISPR/cas9, let’s take an indepth look at both with the assistance of the article about Gene Editing to end Malaria from Vox.

 

So, what is Malaria? According to the Center for Disease Control, Malaria is a mosquito-borne disease caused by a parasite. The four kinds of malaria parasites that infect humans are Plasmodium falciparum, P. vivax, P. ovale, and P. malariae. Typical symptoms causes people to experience fever, chills, and flu-like illness. Left untreated, they may develop severe complications and die. Basically, Malaria has been affecting the global population for decades.  Now, you might be asking yourself: then, what is CRISPR/cas9? Fantastic Question! According to the National Institute of Health, CRISPR/cas9 is recent biomedical technology phenomenon that is drastically changing the genome editing space. In specifically, CRISPR/cas9, which is short for clustered regularly interspaced short palindromic repeats and CRISPR-associated protein 9, has generated a lot of excitement in the scientific community because it is faster, cheaper, more accurate, and more efficient than other existing genome editing methods.

 

So, here is the big question: why does it matter? Here is why it matters. When looking at Anopheles Gambiae Mosquito larvae, a common carrier of the Malaria parasite, in a lab in the United Kingdom, a couple of researchers noticed that all of the larvae had a physical red fluorescent phenotype. Although this doesn’t sound shocking, this is extremely shocking as only one parent had the red fluorescent recessive genotype and the other had the dominant wild type, so the expected offspring would be fifty percent with the red fluorescent gene and fifty percent without the red fluorescent gene, but all of the Mosquitos had the red fluorescent gene. This gene has been linked on Mosquitos to the fertility of female mosquitos. Now, you might be asking yourself: when does CRISPR/cas9 come into play? Well, CRISPR/cas9 can target and locate a specific gene, cut, enter itself in and then passed onto the abundant and constant offspring. As a result, when the CRISPR/cas9 is utilized to alter the mosquito population to be resilient to the Malaria parasite and could “wipe” Malaria from the future history of the planet.

 

In reality, I could never say that this is bad thing as it is working to save lives of hundreds of thousands of people globally. As a matter of fact, I would believe the majority of the population would say this is a good thing, but I am going to say this: do it, but do it right. This is something that needs to be done, Malaria has wreaked havoc on our global community for decades and we must move past that, but any small mistake would halt progress in this field for year. In conclusion, let’s keep having a serious discussion on changing the status of Malaria globally.

 

Thank you!

 

From your favorite bacteria,

SAMonella

 

Fighting the mosquito disease problems with… mosquitos?

Since the discovery of CRISPR-Cas9 system (Clustered Regularly Interspaced Short Palindromic Repeats), gene editing has become a highly debated topic. One of the reasons backing the use of CRISPR-cas9 is to prevent diseases. These diseases include mosquito-borne diseases such as zika, dengue fever, and malaria.  Malaria in particular kills around 3,000 children every year. Various groups of scientists have worked on genetically modifying mosquitos to stop the spread of malaria by making female offspring sterile and unable to bite, making male offspring sterile, or making mosquitos resistant to carrying diseases. A point of concern was if the modified gene would stay relative and would carry from generations. In order to make offspring, genes from both parents must be used, resulting in the offspring carrying the modified gene only half the time.  In particular cases, mutations would occur in the altered DNA, which nullified the genetic changes.  This has been solved by developing a gene drive, which makes the desired gene dominant and occur in the offspring almost 100% of time.  This entails almost the entire mosquito population could have this modified gene in as little as 11 generations.

Image by Author

Recently, the government of Burkina Faso, a small land-locked nation in west Africa, has approved for scientists to release mosquitos that are genetically modified anytime this year or next year.  The particular group of mosquitos to be released first is a group of sterile males, which would die rather quickly.  Scientists want to test the impact of releasing a genetically modified eukaryotic organism in the Africa. It is the first step in “Target Malaria” project to rid the region of malaria once and for all.

 

One of the major challenges in gaining allowance to release the genetically modified species was the approval of the residences, who lack words in the local language to describe genetics or gene editing.  Lea Pare, who leads a team of scientists modifying mosquitos, is working with linguists to answer questions the locals may have and tp help develop vocabulary to describe this complex scientific process.

What do you think about gene editing to possibly save millions?

Read the original article here.

View a video explaining how scientists can use genetic engineering to fight disease here.

CRISPR/CAS9: Potential to destroy malaria?

CRISPR. Sounds more like a new brand of potato chip than something potentially revolutionary (Bold new flavor. Bold new crunch. CRISPR.). Nevertheless, this tool used for easy gene editing and slicing is tearing up the science world because it could be the key to combatting disorders and diseases.

Recent research indicates that CRISPR/Cas9 based genome editing tools could aid in the fight against malaria, one of the “big three” diseases that has long affected and continues to affect humans worldwide. How is CRISPR/Cas9 able to do this?

CRISPRs (Clustered Regularly Interspaced Short Palindromic Repeats) originally are how bacteria protect themselves from foreign viruses. CRISPRs contain DNA from viruses that have attacked the bacteria, and so when a similar virus attacks, the bacteria knows that this virus and his DNA are bad. Essentially, CRISPRs allow bacteria to build up immunity. When foreign DNA is detected, the Cas9 enzyme is guided by the CRISPR and is able to cut the desired DNA. Scientists have come up with a way to engineer and manipulate the CRISP/CAS9 system into other organisms (such as mosquitoes) so that we can successfully edit genome sequences and genes to produce desired results. We take advantage by specifying which genes the Cas9 should cut/replace, and then it does just that. Therefore, the CRISPR/Cas9 system allows us new genome editing potential like none before.

Made by Viktoria Anselm.

How does this apply to mosquitoes and malaria? Scientists experimented with genetically modified malaria-transmitting mosquitoes (Anopheles gambiae), altering the fibrinogen-related protein 1 (FREP1) gene on them. This gene essentially codes for a protein that makes mosquitoes a vector for malaria. The scientists used the CRISPR/Cas9 to inactivate this gene.

The results produced mosquitoes with significantly less transmission of malaria to both human and rodent cells. However, these mosquitoes have “reduced fitness”: a significantly lower blood-feeding propensity, egg hatching rate, a retarded larval development, and reduced longevity after a blood meal. Essentially this means that these mosquitoes have a low chance of affecting populations of mosquitoes in the wild without being “pushed” by scientists, where scientists are “forcing DNA to inherit particular sets of genes.” This is called a gene drive. With a strong push for a couple of years, there is potential for worldwide mosquito populations to be significantly changed in 10-15 years.

Photo taken by JJ Harrison

I chose to write about this new research and potential breakthrough because it really means something to me, as I have lived in and visited countries threatened by malaria. I had to take preventative pills every morning, and I would have to sleep in a restrictive mosquito net. All that made me wonder about and feel for a kid in the same country who didn’t have those things and how he or she would manage without those barriers to malaria. Having said that, I really do believe this is a worthwhile option we should explore, and I think it can make a difference for the world.

What do you think? Do you think it is realistic for theses mosquitoes to change the entire mosquito population and effectively help reduce malaria transmission? Will CRISPR/Cas9 work as we hoped? Or is it too good to be true?

Deleting Genes to Stop Malaria

A new discovery has highlighted the positive effects that the revolutionary new gene editing tool, CRISPR-Cas9, can have. Scientists at the Johns Hopkins Bloomberg School of Public Health’s Malaria Research Institute have discovered that the deletion of a single gene from the Anopheles Gambiae mosquito, called the FREP1 gene, yields promising results in the eradication of the malaria disease.

 

Image result for mosquito gene editing

Gene Editing

The FREP1 gene has been associated with being a malaria “host factor” gene because it helps the parasite live in the gut of the mosquitoes.  However, the scientists, using the CRISPR-Cas9 gene editing procedures, have been able to delete the FREP1 gene from the mosquitoes and have seen significant decreases in the spread of malaria. Without the host factor gene, the parasite has difficulty surviving in the mosquito, which decreases the spread of the disease to other organisms.

 

The deletion of the FREP1 gene had other effects in addition to the resistance of the malaria parasites. In the mosquitoes where the gene was deleted, many showed no signs of sporozoite-stage parasites in their salivary glands, which can spread to humans through mosquito bites. George Dimopoulos, PhD, professor in the Bloomberg School’s Department of Molecular Microbiology and Immunology, commented on the study, saying that “if you could successfully replace ordinary, wild-type mosquitoes with these modified mosquitoes, it’s likely that there would be a significant impact on malaria transmission”.

Hello, CRISPR and Goodbye, Malaria

Everybody hates mosquitoes. Not only are they annoying pests that bite us during the summertime, but they are also transmitters of the parasite that spreads malaria–Plasmodium.  However, scientists believe that they have found a way to wipe out malaria for future generations. By using CRISPR in order to alter the fibrinogen-related protein 1 (FREP1), Plasmodium can be stopped from spreading amongst human beings.  The alteration stops the plasmodium from reaching the mosquitoes’ salvatory glands, effectively halting transmission into the human bloodstream.

However, although CRISPR is a lot less drastic than simply wiping out the mosquito population, it does come with minor setbacks.  The alteration made to the FREP1 gene causes the fertility of the mosquito as well as the egg-hatching rate to drop.  These effects cause the reproduction rates of the altered mosquitoes to be significantly lower than that of other mosquitoes.  If the modified mosquitoes are not able to reproduce, then the genetic modifications are unlikely to have any real effect on the transmission of malaria since they are not being passed on generationally.

The solution? Alter the female mosquitoes.  Only female mosquitoes transmit malaria, so scientists have realized that altering the genetic code of female mosquitoes might be the way to solve the problem with reproduction.  This way, the mosquitoes are able to maintain the genetic resistance to Plasmodium whilst avoiding the dramatic drop in reproduction.

Even though the alteration of mosquitoes’ genetics is definitely a scientific feat, there are no certainties when it comes to this attempt to stop malaria. Nobody is positive about whether or not CRISPR is the solution, but it is definitely a huge step in the right direction.

Hacking Evolution to Stop Malaria?

Kevin Esvelt is a biochemist, at MIT Media Lab, his approach to dealing with disease is instead of waiting for a disease to infect you, eradicate it completely. His hope is that on animals, such as mosquitos. he could use the CRISPR technology to block the gene. He believes that “we should be able to build organisms that are programmed to be immune to every virus known to infect them“.  By using the CRISPR/Cas9 gene editing and gene drive he, and his team, would be able to block that gene from appearing in the next generation.

C

 

https://commons.wikimedia.org/wiki/Category:CRISPR#/media/File:15_Hegasy_Cas9_DNA_Tool_Wiki_E_CCBYSA.png

 

Although, eradicating horrible diseases such as Ebola and Malaria sounds extremely beneficial; there is some draw back. Malaria, for example, is spread across many nations; therefor, scientist would need permission to genetically alter a species from each nation; but before this can be agreed upon test communities would need to be set up. Esvelt would want to test the CRISPR technology in small, localized areas before moving on to an entire species. Esvelt is confident that with a disease as deadly as Malaria, nations would be able to reach an agreement to go with gene editing. Esvelt hopes that by using CRISPR technology he would be able to create organisms, like mosquitos, in the case of Malaria, that are programmed to be immune to Malaria. If this were to happen these deadly disease would not be able to spread. Hence, Esvelt’s key belief of not waiting for the disease infect you, but rather eradicate it completely,

 

 

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