BioQuakes

AP Biology class blog for discussing current research in Biology

Author: saezhallploid

A CRISPR Controversy

By

On March 12, 2019

In Student Post

The Issue:

A recent article published by Grace Tsoi highlights the ongoing controversy regarding CRISPR, a new technology capable of editing DNA sequences, and thus genomes. Among those experimenting with CRISPR is Chinese researcher He Jiankui, notoriously nicknamed “China’s Dr. Frankenstein.” Many are critical of He Jiankui, as they deem his work with CRISPR — such as producing the world’s first gene-edited babies — inhumane and unethical. He Jiankui, however, argues that CRISPR has the potential to help “…millions of families with inherited diseases or exposure to infectious disease.”

Pictured above is He Jiankui, researcher and associate professor of the Southern University of Science and Technology’s Biology Department.

The Study:

In proving CRISPR’s potential, He Jiankui referenced an experiment in which he was able to produce two healthy twin girls by manipulating their genes, specifically making them resistant to HIV. He Jiankui had ultimate success with CRISPR technology, as the twins produced were not HIV positive, unlike their biological father. To learn more about the threat of HIV during contraception, click here. While He Jiankui expressed pride to his audience, stating, “For this specific case, I feel proud actually. I feel proudest because Mark [father of the twins] thought he had lost hope for life,” some audience members did not feel the excitement. Rather, his animated claims were met with intense criticism.

The Risks and Suspicions:

Given CRISPR’s potential, why are people so critical? Is CRISPR’s label “gene scissors” accurate or oversimplified? Regardless of these answers, it is undeniable that utilizing CRISPR for human embryos is a much more complex process. As Kenneth Lee, a biomedical sciences professor at the Chinese University of Hong Kong, explains it, using CRISPR in human embryos is “highly risky,” and could potentially mutate other genes in the process. As a result, the embryo might not survive, or could acquire deformities and/or other genetic disorders. Adding another element to the audience’s suspicion of He Jiankui’s experiment was the secrecy surrounding it, as he failed to answer why he initially hid it from Chinese officials. Failing to consider the opinions of these aforementioned officials has left many questioning the genuine ethics of He Jiankui’s experiment. In defending his work, He Jiankui emphasized that every individual involved consented to his experiment and were well-educated on the study itself. However, the consent form uploaded to his website, explicitly states that He Jiankui would not be held responsible for any unintended gene mutation. Moreover, the University where he conducted his experiment appeared unaware of his lab work, thus rendering an investigation of He Jiankui’s activities. Although China is a more “relaxed” country regarding its gene editing rules (gene editing is banned in the U.S., as well as many other countries), He Jiankui has faced condemnation from many Chinese scientists. Despite this, he plans to expand his studies, focusing next on another gene-edited pregnancy — yet another controversial experiment that will prove to either have potential or deep ramifications. 

*Sing in Rihanna’s voice* Breath out, Breathe in (mRNA)… American Oxygen!

By

On January 14, 2019

In Student Post

Researches at the Massachusetts Institute of Technology (MIT) have designed a potentially groundbreaking tool for helping treat lung disease. Their design? One might find the answer rather surprising: inhalable mRNA.

What is mRNA?

Also known as messenger ribonucleic acid, mRNA is a subunit of RNA, and is responsible for carrying the genetic information copied from DNA in the form of a code. More specifically, mRNA is synthesized during transcription. As explained in the article, mRNA, “encodes genetic instructions that stimulate cells to produce specific proteins.” Click here to learn more about mRNA.

The Benefits:

Inhalable mRNA? Yes, you read that correctly. Essentially, patients would inhale the mRNA in an aerosol form. By doing such, the mRNA would come into direct contact with the patient’s lung’s cells, which would then trigger the production of “therapeutic” proteins. As stated in the article, such mRNA molecules, “[turn] the patients’ own cells into drug factories.” If done successfully, mRNA has the potential to treat a myriad of lung-related illnesses, cystic fibrosis among them. Daniel Anderson, an associate professor in MIT’s Department of Chemical Engineering, expresses confidence regarding the findings, stating, “We think the ability to deliver mRNA via inhalation could allow us to treat a range of different disease of the lung.”

Obstacles:

Presently, scientists face the challenge of targeting cells with the mRNA aerosol molecules by using methods which are both safe and efficient. Additionally, scientists are tasked with the challenge of transporting these mRNA molecules in protective carriers, as the body’s natural reaction is to break mRNA down.

The Experiment:

In order to determine the impact of inhalable mRNA, Dr. Daniel Anderson has successfully manipulated a mice’s lung cells to produce a target protein. Dr. Anderson and his lab have begun designing materials which can transport mRNA to organs such as the liver. In particular, he and his lab utilized polyethylenimine (PEI), as it doesn’t break down easily. However, this very aspect of the polymer has the potential to cause side effects. In an effort to avoid these unwanted symptoms, the team moved on to a biodegradable material called “hyperbranched poly”. To test this material, the scientists converted the material into a droplet form, using a nebulizer to deliver the inhalable mist to a group of mice. Twenty four hours later, the team found that the mice were indeed producing the sought-after bioluminescent protein. Moreover, with the decrease in mRNA dosage came the decrease in protein production.

Pictured above is polyethylenimine (PEI), the initial polymer used in Dr. Anderson’s experiment.

The Future of Inhalable mRNA:

Such developments, such as those performed by Dr. Anderson and his team, increase the potential reality of testing on patients. To read the full findings of the aforementioned experiment, click here.

I Can’t Sleep Because of… My Gut?

By

On November 10, 2018

In Student Post

The Issue at Hand:

Unfortunately, the following scenario is all too common for some of us: We lie in bed, eyes closed, pacing our breath, all in a failed attempt to fall asleep. We periodically check our alarm clock, only to see the time get later and later. 2:30 a.m.? How could it be?! Well fellow reader, as Kate Leaver points out in her article ‘Could it be your gut keeping you awake at night?,’ there is a potential (and perhaps surprising) explanation to such restlessness… microbes.

So What Exactly Are Microbes?

In essence, microbes are microorganisms, such as bacteria. There are trillions in the small intestine alone. Despite their microscopic size, they have the ability to impact mood, digestion, and, as previously mentioned, sleep.

Above is an image of gut microbes. (Credit: Rocky Mountain Laboratories)

Ongoing Studies:

As Matt Walker, the director of the Center of Human Sleep Science at the University of California, Berkeley, points out: “…we don’t fully understand yet…the role of the microbiome in sleep.” However, various studies are currently exploring this phenomenon. Among these include a study conducted by scientists at the University of Colorado, which links microbes and quality of sleep by utilizing both probiotics (i.e. live bacteria) and prebiotics (i.e. carbohydrates such as fiber). Essentially, probiotics and prebiotics supplement the ‘good’ bacteria/microbes in our guts. In fact, after taking supplements for five days, insomniac Dr. Michael Mosley calculated that his time awake in bed decreased drastically from 21% to a mere 8%. Other sleep experts, such as clinical psychologist Dr. Michael Breus, attest to the link between sleep and microbes. Dr. Beus believes that, “…the microbial ecosystem may affect sleep and sleep-related physiological functions in a number of different ways: shifting circadian rhythms, altering the body’s sleep-wake cycle, affecting hormones that regulate sleep and wakefulness.” Finally, Tim Spector, professor of genetic epidemiology at King’s College London, points out how people with depression and people with poor sleeping schedules often have, “…abnormal microbes in the gut.”

What to Do Going Forward?

Given that the aforementioned studies are ongoing, and thus lack solidity, it can be difficult to determine how to improve one’s sleeping schedule. However, Mr. Spector adamantly believes that a healthy diet is the key to eliminating sleep disturbances. More specifically, he proposes the consumption of ‘gut-friendly’ foods, which are unprocessed and high in fiber. These include, but are not limited to, berries, green tea, dark chocolate, nuts, and seeds. Hopefully, with these tips, along with future discoveries, you will find yourself fast asleep in no time!

‘Wait, you’re not my child!’: Why Parents Are Having Difficulty Differentiating Their Offspring from Non-Offspring

By

On October 10, 2018

In Student Post

The Discovery:

Researches at the Universities of Cambridge and Exeter are currently exploring issues regarding offspring recognition, particularly among Digger wasps and, more generally, among insect, bird, and fish species. Findings have presented the inability for a parent to recognize their offspring. Accredited with justifying this anomaly is Crozier’s effect. In essence, this effect requires individuals to simultaneously act as hosts and parasites.

What is a parasite’s motive?

I presume many of us find it difficult to envision our parents blatantly abandoning us. To a parasite, however, brood parasitism isn’t all that complicated of a decision. A parent’s decision to abandon their offspring (by placing its offspring in another’s nest, for example), is based on logic. Professor Jeremy Field of the University of Exeter explains how by abandoning their offspring, parent’s diminish the effort it would talk to raise their kin.

A Failure to Recognize ‘Cuckoos’:

Scientists have hypothesized as to why parents are failing to recognize their non-offspring. In fact, researchers believe that wasps whose features varied genetically correlated with wasteful rejection interactions. Therefore, it is possible that the frequency of such disadvantageous features diminished overtime (think: evolution). Ultimately, this would increase the number of similar-looking wasps, thus enabling parasitism to occur more regularly. To learn more about this study, please click here.

Above is an image depicting brood parasitism: a Brown-headed Cowbird egg in a Phoebe nest.

The Problem with Rejecting ‘Cuckoos’:

At times, the victims of brood parasitism are able to recognize cuckoos among their offspring due to blatant signs of genetic variation. Logically, one would assume that the host would then reject the non-offspring. However, this is not always the case. As shown in a Digger wasp study, the hosts actually kept foreigners in their nest, as removing them would require immense energy, along with a depletion of resources (i.e. food from the nest would be removed with the cuckoo).

The Investigation/Results:

To further investigate brood parasitism, scientists placed foreign wasps in a burrow to gage if the host would accept or reject its non-offspring. The results depicted that host did not treat its non-offspring any differently from its actual offspring. This leads scientists to believe that not only are wasps unable to differentiate between the two, but they are more likely to base rejection off of other aspects such as age.

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