Unlocking the Key Mechanisms of Hepatitis B Infection

Cecilia Panfil (CHM, 2022) and Alexandra Libby (PNI, GS)

Worldwide, approximately 250 million people have tested positive for the Hepatitis B virus (HBV). The virus infects the liver, causing severe damage when left untreated, such as chronic infection, liver fibrosis, liver cancer and cirrhosis. The likelihood of an adverse outcome or chronic illness is higher if the disease is contracted in childhood. Transmission can occur either through birth (i.e., the mother was infected) or close contact (e.g., sexual incourse or needle sharing for injectable drugs)1. HBV is a significant global health problem; overall, it is estimated that 650,000 people die each year from HBV related illnesses2.    

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Infectious mosquitoes decode the unique smell of humans to pick their next meal

Review written by Olivia Duddy (MOL, G4)

Some mosquitoes are picky eaters. For example, females of the mosquito subspecies Aedes aegypti preferentially select humans over non-human animals as their blood host (only females mosquitoes bite). The consequence of Ae. aegypti’s preference for humans is its emergence as a global driver for the spread of infectious diseases like dengue, yellow fever, and Zika. So what attracts this mosquito so strongly to humans? Your smell. 

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Designing a molecular light switch

Review by Abigail Stanton (MOL, G1)

Living things are composed of an intricate set of chemical machinery, each piece refined over billions of years of evolution to perform the tasks required to grow, reproduce, act, and react. A principal challenge of biochemistry is understanding how each microscopic gear (or protein) works within the dynamic context of a larger machine (the cell and, eventually, the organism as a whole). To dissect these complex pathways, researchers need ways to interact with the cell. They need tools that act like molecular tweezers to remove pieces, to change them, and to turn mechanisms on and off. As our understanding of each component grows, our biochemical toolbox expands, allowing for even more biological discoveries, which in turn allows for the development of ever more sophisticated tools. 

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A new algorithm is helping to decipher the language of morphogenesis

Review written by Sarah McFann (CBE, G5)

Language is ever-evolving. With each new generation, language structures such as word pronunciation, usage, and meaning mutate and change as they are passed imperfectly from parent to child. Similarly, bodies have the chance to evolve with every generation. Mutations in the germ line—eggs in females and sperm in males—give rise to the genetic variation that allows form and function to evolve. With each new germline mutation, the nucleotides that make up the genetic code are altered due to imperfect DNA replication. These mutations can code for changes to protein structures or protein amounts, altering the way bodies are constructed as they develop and the forms they take on along the way.

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Learning from our past: Using medical history to guide patient care

Review written by Kimberly Sabsay (LSI, GS)

The transition to a highly digitized society is well underway. Hospital data and medical charts are no exception. According to the CDC, over 85% of healthcare organizations have adopted Electronic Health Record (EHR) systems as of 2017. EHRs, while increasingly complex, could very well hold the secret to advancing patient care and diagnostics. EHRs contain medical history, medications, and test results, much like a regular health record, while also providing real-time information and tools to automate treatment plans. Predictive healthcare analytics are at our fingertips, and a novel statistical framework designed by researchers at Princeton University unlocks the massive potential of personalized, predictive, and real-time medical monitoring systems.

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A computational model for automated tracking of socially-interacting animals

Review written by Andy Jones (COS, GS)

Understanding the link between neural activity and behavior is one of the long-running goals of neuroscience. In the information age, it is becoming more and more common for neuroscientists to take a data-driven approach to studying animal behavior in order to gain insight into the brain. Under this approach, scientists collect hours’ or days’ worth of video recordings of an animal, relying on modern machine learning (ML) systems to automatically identify exact locations of body parts and classify behavior types. These methods have opened the door for more expansive studies of the relationship between brain activity and behavior, without relying on laborious manual annotations of animal movements. 

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New (inter-)vistas of protein interactions

Review written by Laura A. Murray-Nerger (Molecular Biology, G6)

As primary and secondary school students, we learn that cellular organelles have specific functions. For example, the mitochondria is often called the “powerhouse” of the cell because it makes energy that drives other cellular processes. However, we often don’t learn about the multifaceted functions of these well-known organelles or learn about some of the less-well studied organelles, including the peroxisome. Moreover, as we learn about the functions of these organelles, it is easy to forget that they are filled with many proteins, each of which participates in a variety of functions. Importantly, these proteins do not work in isolation, but rather by interacting with each other, which creates a complex network of protein-protein associations that ultimately determine cellular fate. In their recent paper, the Cristea lab has built a computational platform that can be broadly used to assess the changes in protein-protein interactions in any biological context. They employ this newly developed tool to understand the protein-protein interactions that underlie alterations in mitochondrial and peroxisomal function during viral infection.

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Worms decipher a bacterial code to drive multigenerational change in behavior

Review written by Olivia Duddy (MOL)

Segments of DNA, called genes, encode the expression of an organism’s traits. Genes are heritable, meaning that they are transmitted from the parent to their progeny. Additionally, scientists have uncovered mechanisms that enable changes in gene function, independent of changes in DNA sequence, that are also heritable. The study of these mechanisms, collectively known as epigenetics, has revealed ways in which the environment shapes our biology in the context of health and disease.

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Why some mosquitoes prefer biting us

Review written by Jessi Hennacy (MOL)

There are about 3500 mosquito species worldwide, but only a handful of them are responsible for the transmission of mosquito-borne illnesses such as malaria and dengue fever. Whereas most mosquito species are generalists that lack a preference for a particular animal, the specialist mosquito species that prefer biting humans over other animals are also the species that most widely spread human diseases. Understanding the environmental factors that are driving these mosquitoes to prefer humans could help uncover strategies for mitigating the spread of mosquito-borne illnesses. It is therefore vital for public health to ask why and how certain mosquitoes have evolved to target humans.

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A C. elegans model reveals mechanisms behind reproductive aging

Written by Ashley Chang (MOL, 2021) and Rebekah Rashford (PNI, G3)

Physiological decline is a natural component of human aging. One of the biological processes perhaps most rapidly affected by this decline is that of reproduction in women. The quantity and quality of a woman’s eggs decreases as she ages, thereby reducing the likelihood of a successful pregnancy as she approaches her late 30s to early 40s. Pregnancy in humans at all is relatively impossible after menopause, which typically occurs in the late 40s and beyond. Because of these biological restrictions, doctors and researchers have developed treatments to help women who want to have children later in life, such as freezing their eggs or in vitro fertilization followed by freezing of the embryos. While these treatments have undoubtedly changed the landscape of modern conception and fertility, they do not directly combat the deleterious effects of reproductive aging. Instead of creating systems that circumvent the inevitable, what if we could challenge the issue head-on by preventing deterioration in the quality of the egg precursor, the oocyte, and extending the reproductive age-span? 

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