BioQuakes

AP Biology class blog for discussing current research in Biology

Author: nucleahtide

Genetically Modified Babies?

A decade or two ago, the idea of being able to modify embryos was straight out of a science-fiction movie. However, last November, Chinese scientist He Jiankui genetically modified twin girls’ embryos to have resistance to the HIV virus using a process called CRISPR. His actions have sparked a global panic, as many people feel that current regulations are not enough to keep the scientific community’s actions ethical.

To understand this issue, it is important to understand its individual components. CRISPR is a gene-editing tool that was discovered in 2007 and became widely used in 2013. Essentially, a scientist decides what portion of DNA they would like to alter, and transcribes the sequence into RNA. This RNA finds the portion of DNA with the specific code and then the Cas9 enzyme “cuts” the DNA, allowing a new sequence of DNA to take its place.

The image depicts functions of CRISPR Cas9 technology.

Dr. He used CRISPR Cas9 technology to try to block the HIV pathways in twin girls while they were still embryos. As this experiment was recent, the long-term effects of it are unclear. In addition, as these girls were not developed at the time of their gene editing, they did not give consent to have a treatment that could be detrimental to their health. Furthermore, looking at the Centers for Disease Control website, HIV is primarily acquired by the use of unsafe needles to inject drugs and sexual contact. Using clean needles and condoms can greatly decrease one’s risk of getting HIV, and if a HIV-positive person takes suppression medicines, the viral content of HIV in their blood can become undetectable. Dr. He’s actions gave the twin girls undue risk, with little possible benefit.

In the future, this method of gene editing may be used to prevent or treat genetic diseases, but people have little knowledge of the long-term implications of using this technology on embryos. At the moment, the lack of global legislation regarding this gene-editing technology leaves a lot to be wondered about the future of this tool. According to Victor Dzau who works in the United States National Academy of Medicine, “The silver lining is that the world was awakened by the conduct of Dr. He, and we are all working very, very hard with all good intentions to make sure that this doesn’t happen again—not in the fashion that He did it. And that someday, if and when the technology is ready—and I think all of us are very bullish about this technology—that it will be helping humankind in the right way, knowing the risks and knowing the benefits.” After Dr. He’s experiment, many are in favor of halting the use of CRISPR on human embryos for at least five more years, so more research can be done on the subject. However, legislation, which the world has seen little of, holds a stronger weight than mere recommendations. In Russia, Denis Rebrikov is planning to create CRISPR babies, and regulations in the country regarding his specific goals remain unclear. How will CRISPR embryo editing evolve in the coming decades? Will CRISPR gene editing be as common someday as IVF is today?

 

Mothers, Babies, and the Gut Microbiome

In the past, doctors knew there were certain women were at a higher risk for having premature babies, such as having high blood pressure, diabetes, or multiples, but doctors have only recently discovered the significance of a woman’s microbiome at the beginning of the chain reaction in a woman’s body ending in birth.

Stanford researchers have created an “Immune Clock” using multiple factors, such as the mother’s “gut, vaginal and oral microbiomes, blood levels of proteins and metabolism-related molecules, plus fetal genetic material released into the women’s blood”. They have found that this algorithm creates extremely accurate results and currently has thousands of data points.

In a separate study, scientists discovered that women with more diverse inflammation microbes in their microbiome were more likely to miscarry. Although this research is interesting, broad conclusions are hard to draw because each woman has a different microbiome, based on not only their genetic makeup, but also their diet, environmental factors, and emotional stress.

Interestingly, a mother’s microbiome is not the only important factor for a premature baby. In a University of Rochester study on premature babies’ stool, they discovered the importance of a baby’s gut microbiome. Premature babies with more “good” bacteria in their diapers tend to fare better than those with less.

The image above shows a baby whose diaper will soon likely contain gut bacteria!

Today, many doctors in the NICU push premature babies to consume more calories, although this method alone often does not result in growth. Certain gut bacteria essential to growth thrives on different groups of food, and since there is a high importance in having distinct stages of a baby’s gut microbiome development, adjusting the baby’s nutrient consumption may help it to grow and thrive.

The often-overlooked property, the gut microbiome, has proved itself as an essential contributor to both mothers and babies to thrive. Would you ever submit your data to the Immune Clock to find out your risk of having a premature baby?

Danger in the Growing Animal Product Industry

As more countries begin to mass produce animal products, more antimicrobials are used to keep the animals from spreading disease. However, this commonplace antimicrobial use results in antimicrobial resistance, specifically in low and middle-income countries with few rules in place. Interestingly, most instances of microbial resistance occur in Asia and South America, but there are few instances in Africa.

Once animals develop antimicrobial resistance, it affects the rest of the food chain. When farmers give their animals antimicrobials, all of their stomach bacteria besides the resistant kind is killed. As a result, antimicrobial-resistant bacteria can spread to the soil, to produce, and to humans. Potentially, in a world without antimicrobials, even simple surgeries can be unimaginably dangerous, and diseases can be difficult to treat. At the moment, in certain countries, people are developing drug-resistant strains of malaria, tuberculosis, influenza, and even HIV.

A description of how drug resistant bacteria reproduce after other bacteria are killed.

Researchers have multiple ways of testing the spread of antimicrobial resistance. They can search for pockets where animals carry illnesses that are resistant to antimicrobials, such as penicillin. Researchers now test how many animals have resistance to drugs by giving them drugs and seeing if the animals respond. In antimicrobial-resistant hotspots, up to 50% of animals may not respond to drugs. People can struggle to find accurate information regarding the amount of drug-resistant animals, specifically in South America, where information is not always public. Researchers have also created the Resistance Bank, where people can see the specific antibiotics animals are resistant to. Its goal is to increase awareness in lower-income countries who may not have the resources to publish scientific articles describing the levels of antimicrobial resistance.

How can we protect ourselves from this growing threat? On a global scale, the spread of antimicrobial-resistant diseases can only be completely slowed with the halting of overuse on people and animals. In contrast, if we each wash our hands often, cook meat before eating it and use separate preparing utensils for raw meat and all other foods, and spread awareness about the overuse of antibiotics, perhaps each one of us can help halt the spread of antimicrobial-resistant infections.

 

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