BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: mosquito

Using Mosquitoes’ Greatest Asset Against Them

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On December 7, 2023

In Student Post

What if mosquitoes were not a threat anymore? The most deadly animal known to man, harmless?

Aedes aegypti CDC-Gathany

Even today, even with deaths down 31% from 2010 to 2019, mosquitoes still kill around 1 million people a year. According to the CDC, in 2020 they killed over 600,000 to malaria alone. Excluding other viruses such as dengue or West Nile virus.

 

But scientists intend to turn their affiliation with viruses into an advantage. By implanting their own virus into mosquitoes, one that can limit the transmissibility of other ones.

 

Wolbachia. A virus preexisting in an abundance of other bugs to the point of it not harming the ecosystem. A virus that can suppress the transmission of viruses. A virus that will be passed down the generations.

 

In Medellin, Colombia, a mosquito factory exists solely for this purpose. To breed enough of the Aedes aegypti mosquito, that will propagate this virus throughout the town. Rather than the insecticide trucks barrelling through the streets, spraying the air and killing the water, mosquito eggs are injected with incredibly fine needles, nurtured, then released. And there were results. Mosquitoes who picked up a virus were less likely to transmit it to humans. In Yogyakarta, Indonesia it worked too.

 

Whilst the A. aegypti mosquito originally originated from Africa, they escaped via the slave trade, and later, would follow the paths of troops in World War II. And now many communities are affected by it.

 

So the introduction of something to suppress these fatal diseases is good, right? 

 

This program is too new. The Wolbachia might work now, but it’s only a matter of time before these viruses mutate and harness the power of the increased number of mosquitoes. “Mosquito populations are increasing and additional methods are needed to control the mosquitos during their adult stage,” the EPA states in regards to the mosquito population in Puerto Rico. And they do not mention the added mosquito populations. If say, dengue mutates, changes even the slightest bit of its genetic code, and Wolbachia no longer works, then we have simply increased the problem, kicking that can down the road.

There is a chance that a virus will mutate every time it duplicates its RNA/DNA, and since it occurs quite frequently, there is a solid chance for a mutation that ignores Wolbachia to become prevalent in mosquitoes. If the epitope (the spike protein that antibodies recognize) in one of the viruses Wolbachia seeks to prevent changes significantly, Wolbachia’s gift will turn back into its weakness. Akin to how old Covid vaccines no longer work, but I digress.

I cannot say for certain that this may occur, but then viruses are like elusive fish: nearly impossible to predict or ensnare, yet still so prominent in its effects. 

 

Please tell me if you think this will work. These studies feel a little too optimistic, but I hope I’m wrong.

 

Do mosquitos bug some people more than others?

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On October 25, 2022

In Student Post

Over time, many have questioned whether or not some people are more susceptible, or attractive, to mosquitoes than others. Some have thought that it was one’s blood type, some have thought it was due to smell, and some have thought that the idea is truly a myth. It was highly suggested that attraction to mosquitos was due to scent, but never confirmed if true and what scents they would be attracted to.

Aedes aegypti during blood meal

A recent study has that scent is the answer to attraction of mosquitoes, and what scents they prefer the most. In this study, participants were asked to wear stockings on their arms for 6 hours, to imbue the stocking with each person’s unique smell. The researchers then put one piece of a volunteer’s stocking next to a piece of another observer’s stocking, and monitored whether or not the mosquitoes seemed to prefer one stocking over the other. The researchers concluded the mosquitoes definitely appeared to prefer certain stockings over others, one of the stockings in particular had “an attractiveness score ‘over 100 times greater’ than that of the least attractive subjects”. 

 

 

After the study, the researchers found that mosquitoes preferred stockings with more carboxylic acids. Carboxylic acids are organic compounds, which are produced by humans on our skin, moisturizing us, protecting us, and producing a sweaty smell on our skin. From the time we are born, us humans keep a constant Carboxylic-acidlevel of carboxylic acids on our skins, meaning that for the most part, our “attractiveness” towards mosquitoes is level for our entire lives. 

 

 

 

You might think that this is the end, that this study has proven that there is no hope for you to lose the status of “mosquito magnet” if you already are susceptible to mosquito bites, but this is not true. This study leads the way in future projects to reduce mosquito bites in mankind, as it revealed what the true issue we had to attack was. A biologist who specializes in mosquito research, Omar Akbari, has stated he is using the research to aid him in the development of mosquito repellents that will work for long periods of time(months). Akbari has already discovered specific carboxylic acids that mosquitoes are particularly attracted to, and is working with the Department of Defense to aid them in their work in insect control. He is working alongside the US government to develop these repellents, truly proving that there is hope for those who feel they are 

 

Let’s Talk About Malaria

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On March 12, 2019

In Student Post

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?

By

On October 10, 2018

In Student Post

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.

A Cure for Zika? Scientists successfully test a DNA-based Zika Vaccine

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On October 16, 2017

In Student Post

The Zika virus, widely known for its 2015 Latin and North America outbreak, is a mosquito-borne and transmitted virus that develops neurological complications and birth-defects in those infected. The Zika virus is able to be transmitted from a pregnant woman to her fetus, causing microcephaly– abnormal development of the brain. Currently, there exists no vaccine that would fully treat the virus, however, a solution may be in the works.

(Photo from Wikipedia Commons)

David B. Weiner, Ph.D., an executive vice president of The Wistar Institute and a developer of the Zika vaccine notes that, “Synthetic DNA vaccines are an ideal approach for emerging infectious diseases like Zika”. Synthetic DNA vaccines are vaccines with genetically engineered DNA. They work in the same way as regular vaccines, inciting cells to produce specific antigens for immunological responses. Synthetic DNA vaccines can also have potential benefits over traditional vaccines, including a higher predictability, stability, and ability to be manufactured and distributed safely and rapidly.

The current Zika vaccine in development, GLS-5700, houses multiple strains of genes with DNA instructions that tell a hosts’ cells how to react and fight off a Zika virus antigen. In late 2016, researchers tested the vaccine on 40 participants. Two groups of 20 received different does of the vaccine at zero, four, and twelve week intervals. At the end of the experiment, researchers found that all participants had developed Zika-specific antibodies and 80 percent of the participants developed neutralizing antibodies against the Zika virus.

Zika 2015-2016 Outbreak (Photo from Wikipedia Commons)

Although rare in the United States, Zika continues to threaten millions living in South and Central America. Despite being in its last stages of development, GLS-5700 and other Synthetic DNA vaccines are still prohibited from being used in the United States- although this may change with the introduction of the Zika vaccine. The future of Synthetic DNA vaccines and viral disease prevention lies in the success of the GLS-5700.

 

 

 

 

Pythons to Blame for Increase in Dangerous Mosquitoes in Florida

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On October 11, 2017

In Student Post

The Invasion of Burmese Pythons in Southern Florida has been well documented over the last few years, and as they increase in number in the Everglades, numbers of many mammals have diminished. The addition of an extra top predator such as the Burmese Python, the second largest snake in the world, growing up to about 19 (19!!!) feet long, has dire implications for the ecosystem of the Everglades and of Florida, but they pose a danger to the humans in the area as well!

That’s right, the Burmese Pythons are causing problems for Floridians. No, Floridians are not soon-to-be victims of a Python takeover, but the disruption of the Everglade ecosystem has begun to become apparent. As Burmese Pythons have lowered numbers of countless different mammals across the Everglades, mosquitoes have less variety among the animals they drink the blood from, per ScienceDaily. As a result, Mosquitoes have been taking more blood from the mammals that remain, most notably the hispid cotton rat. Mosquitoes in the area are now taking more than 75 percent of their meals from this rat, which is a massive 422 percent increase since 1979. Burmese Pythons were first reported in the area in the 1980s. The hispid cotton rat, which so many mosquitoes feed on now, hosts the Everglades Virus, which is transferred to humans by mosquitoes. As if we didn’t have enough reasons to hate mosquitoes. The hispid cotton rat is one of the only hosts for the virus, which causes “fever, headache and even encephalitis” in humans, according to the same ScienceDaily Article.Sigmodon hispidus1.jpg

This new research is not only  relevant because of the increased hatred we all now have for mosquitoes, though. It also represents a landmark in research on invasive species. Nathan Burkett-Cadena informs ScienceDaily that “As far as I am aware, this is the first time that researchers have found that an invasive predator (such as the python) has caused an increase in contact between mosquitoes and hosts of a human pathogen.”

So, python invasions lead to more virus-carrying mosquitoes in the Everglades. Does this make you as uncomfortable as it makes me? Let me know what you think, leave a comment. I for one am glad to be far away from both the pythons and the Everglade mosquitoes.

 

Photos:

James Gathany for CDC https://commons.wikimedia.org/wiki/File:Sigmodon_hispidus1.jpg

Susan Jewell for USFWShttps://en.wikipedia.org/wiki/Burmese_pythons_in_Florida#/media/File:Burmese_python_(6887388927).jpg

 

Harmless Mosquitoes…Yes Please

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On April 13, 2016

In Student Post

What are the most annoying things on Earth? Why, mosquitoes of course. They bite you and their bites are extremely irritating. Mosquitoes also carry life-threatening viruses, such as Malaria. However, scientists have come up with a way to get rid of mosquitoes carrying Malaria with the help of gene drives.

A gene drive is a self-generating “cut-and-paste system” that can sterilize mosquitoes. Well how do gene drives work? They operate using CRISPR/Cas9, precision molecular scissors that cut DNA. Scientists used CRISPR/Cas9 to disrupt the genes that are active in mosquito ovaries. If a female mosquito is missing one of these genes, they become sterile. Gene drives insert themselves into a target gene to assimilate every unaltered gene they pass. They break normal inheritance rules by being able to pass themselves into over 50% of an altered animal’s offspring.

NHGRI-97218

The first gene drive that was made stopped mosquitoes from transmitting Malaria. This new gene drive would eliminate Malaria-carrying mosquitoes in the future by making the females sterile, unable to reproduce. This gene drive is not 100% perfect yet, but scientists are hoping to perfect it soon to be able to release it. They hope that this gene drive will be able to control different insect populations, not only mosquitoes.

Source Article

Mystery Virus Identified

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On January 16, 2015

In Student Post

The Kansas Department of Health and Environment stated that the mysterious virus that killed the farmer in Kansas last summer has been identified as Bourbon virus, named after the county were the patient lived. Doctor Dana Hawkinson, infectious disease specialist, treated the patient for 10 days at the University of Kansas Hospital.  Bourbon virus, a microbe, was identified by the scientist at the federal Centers for Disease Control and Prevention after several months of testing.  Doctor J Erin Staples, a medical epidemiologist at the CDC laboratory in For Collins, CO, stated the virus was a type of thogovirus, part of the larger family called orthomyxovirures.  Hawkinson believe that the virus has been around in milder forms for some time now and people have recovered from it.  The patient entered the hospital with symptoms which included high fever, muscle aches, and loss of appetite.  Upon further testing the patients blood showed elevated liver enzymes and low levels of white blood cells and platelets which indicated tick-borne illnesses.  Hawkinson tested the patient for Rocky Mountain spotted fever and Heartland virus, both came back negative.  Heartland virus is also another recently discovered/named by the CDC tick-borne illness.  There is no treatment for the disease  and the best defense is to wear long garments when working outdoors and wearing bug spray containing DEET.  The risk to the public is low especially because mosquitos and ticks are not active in cold weather.

For more information:

Article from NYTimes

Bourbon virus kills farmer

Virus that killed farmer is identified 

Kansas farmer dead

We Need Mosquitoes?!

By

On October 7, 2012

In Student Post

Picture By maureen_sill, Flickr

Yes, in fact, we do need mosquitoes. And not only mosquitoes but all the other types of insects as well. A recent discovery by Anurag Agrawal, the leader of the study and a professor of ecology and evolutionary biology at Cornell University, revealed that insects are hugely important because of the roles they play in the evolution of plants. In Agrawal’s study, in which he observed the interactions of plant-eating moths and evening primroses, the primroses treated with insecticide lost through evolution the traits that protect them from insects.

 

This points to the idea that if plants don’t need to defend themselves against insects, they stop developing the traits required to defend themselves. The real shocker in this discovery, however, was how quickly the primroses adapted to this situation, in just 3-4 generations. Agrawal “was ‘very surprised’ by how quickly this process occurred, and that such surprises, ‘tell us something about the potential speed and complexities of evolution. In addition, experiments like ours that follow evolutionary change in real-time provide definitive evidence of evolution.”
But why are insects important then? Well, it is believed that many plant traits developed solely as a means of defense against insects. Some of these traits are desirable to people, like fruit’s bitter taste. In addition, with farmers trying to breed certain crops to be resistant to pests, this study shows that some genetic trade-offs might make it impossible to get certain traits in pest resistant plants. So bear with those pesky insects, as their relationship with plants is extremely important.

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