ekauli – BioQuakes

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?

Cows are really cute. They just stand there in the grass, four-legged and everything, eating their grass, mooing, and just living life like cows should. They taste good, and they make milk, which means that we (humans, if you needed that clarification) love to farm them. As a result, there’s a LOT of them (more than 1.5 billion) all over the planet. Seems like a good thing right? I mean, how could too much of this be a bad thing?

Look at this cutie just chillin’. Photo by Daniel Schwen.

Unfortunately, cows have a dark side. Cattle are a type of animal called a ruminant, which have specialized stomach to digest plant material by storing it and fermenting it. Once fermented, the food, known as cud, must be chewed again before digestion is complete. In the cow’s stomach aiding it in this process are tiny microbes known as methanogens. These guys allow cows to digest things like cellulose (plant matter), but produce methane as a waste products. Cows then either burp or fart out this gas.

With all the cows on the planet, the methane being emitted has become a major problem. Methane is a greenhouse gas 25 times more powerful than carbon dioxide, meaning it warms the planet at a much higher rate. Livestock account for 14.5% of all anthropomorphic (human) greenhouse gas emissions, and cattle account for 65% of all livestock emissions. So obviously, cows’ farts and burps are a problem. So how can we fix it?

Our cute friends are a large part of this… Made by Al Rodger.

The three issues, according to microbiologist Lorenzo Morelli, are diet, genetics, and the microbiology of cows. Phil Garnsworthy of Ruminomics, an organization with a goal of reducing cows’ emissions, looks to selection to help lessen the problem. According to him, cattle vary by a factor of two to three on the amount of methane given off. By simply favoring and only breeding those cattle that only emit low amounts of methane, the problem can be immediately mitigated. Dairy Farmers have an extra incentive to reduce methane by breeding low methane cows separate from the environment, as well. The methane represents lost energy that could go into producing more milk, and so adding low-methane to a list of attractive cow characteristics would not only help the environment, but also farmers’ wallets. But plain ol’ artificial selection isn’t the only option.

Changing cows’ diet may also help reduce the problem. Scientists at Aarhus University are looking into producing a genetically-engineered grass to give to cows. By changing and running tests on the DNA of the grass and eventually finding the optimal type, the scientists hope to make grass less stiff and easier to digest for the cows, which would not only decrease methane production due to less activity from the microbes, but also increase milk production.

Cows grazing. Photo by Scott Bauer.

There is an also an option of dealing directly with the microbes themselves and their methane release. For example, Researches at Penn State are studying the effects of 3-nitrooxypropanol (3NOP) on cows’ methane emissions. 3NOP, when put into cow feed, would in theory stop the microbes from producing methane when it binds to the cows’ digestive tracts. Cattle saw a 30% reduction of methane when fed 3NOP.

And finally, there is always the prospect of genetically modifying cows themselves to produce less methane. The tricky part about this is that it’s the microbes that actually produce the methane, not the cows. Morelli says, “We think that animal genetics may well influence their gut microbiology. However, this link has not been proved and we are still in the data collection phase.” Essentially, though we might be far from a GMO cow that produces less methane, it is not outside the realm of possibility. Even now, the Genome Canada project is looking into the genes responsible for lower methane emissions, with the hope of spreading the gene to other populations of cows.

Personally, I believe scientists should be doing whatever they can to reduce methane emissions. This is our planet, and we need to do everything we can to save it. This includes GMO research, which I realize makes some people uneasy, but in my opinion is a great, new way to help our planet and help ourselves. However, any solution that would hurt cows, reduce lifespan, or ruin milk or beef taste should only be used as a last resort. Even then, I would be hesitant to implement such changes. Essentially, what route is the most efficient and practical, and what are you willing to sacrifice? These are the two questions that must be answered in finding a way to reducing cows’ methane emissions.

All in all, it seems cows are on their way to being lesser burdens on our environment. And that’s a great thing, because then I would be able to appreciate their cuteness more without feeling a bit of guilt.

BioQuakes

AP Biology class blog for discussing current research in Biology

Author: ekauli

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