How the egg drives its own development

Review written by Olivia Duddy (MOL, G4)

How do animals produce a healthy egg cell? To answer this, many developmental biologists investigate the complex choreography of factors required for successful egg cell development, called oogenesis. This process is crucial to the survival and reproduction of many vertebrate and invertebrate species and, remarkably, diverse species often employ a common strategy where the growth of the egg cell is supported by an interconnected network of germline, or reproductive, cells. Like cellular factories, the job of the germline cells is to produce and export nutrients to the egg via connecting cytoplasmic canals. The nutrients these support cells supply to the egg include proteins and the nucleic acids that code for them, called RNA transcripts. 

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Newborn mice form memories of their mothers that last a lifetime

Review written by Amy Ciceu (2024) & Adelaide Minerva (PNI, G2)

As youngsters, we develop memories of and connections to our parents, who nurture us throughout not only our childhoods but also much of our lives. These memories and relationships play vital roles in teaching us how to navigate the world. Do other animals form similar memories? A recent study published by the Gould Lab in Princeton’s departments of Psychology and Neuroscience discovered that mouse pups form memories of their maternal caregivers within days of birth and that these memories endure as the pups age into adulthood. 

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Toward personalized medicine: how the gut microbiome shapes patient response to drugs

Review written by Truc Do (CBE, post-doc)

Our microbial residents and their impacts

It has been estimated that there are at least as many bacterial cells in our bodies as there are our own cells1. The vast and diverse collection of bacteria and other microorganisms that live within and on us is known as the human microbiome. We are colonized with microorganisms from birth, but the structure (composition) of our microbial communities evolves throughout our lives2. In recent years, it has become increasingly apparent that human health is inextricably tied to the state of our microbiomes. For example, Crohn’s disease is an inflammatory bowel disease of increasing prevalence. Changes in the composition of the gut microbiota, as a result of diet and other environmental factors, have been associated with severe Crohn’s disease states3.

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A new strategy for putting yeast to work

Review written by Sarah McFann (CBE, G5)

Many household goods, from dyes and plastics to contact lenses and aspirin, are made using petroleum byproducts. Over the past 150 years, chemical catalysts have been optimized to efficiently convert crude oil into starting materials for a wide range of products. Unfortunately, petroleum is a non-renewable resource, and emissions from petroleum processing are a big contributor to climate change. A team of bioengineers from the Avalos Lab at Princeton University is investigating an alternative: a petroleum-free way of manufacturing carbon-based goods that uses genetically engineered yeast to convert sugar into high-value products. 

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Structural insights into the liquid-like center of the eukaryotic CO2 concentrating organelle, the pyrenoid

Review written by Jessi Hennacy (MOL, G4)

All plants use the enzyme Rubisco to capture CO2 during photosynthesis, but Rubisco is hindered by a slow reaction rate and a counter-productive reaction that happens when the enzyme binds to oxygen instead of CO2. Algae, however, have a special organelle called pyrenoid that helps Rubisco capture CO2 more efficiently. Whereas most plants need to express high amounts of Rubisco to capture enough CO2 to grow, the pyrenoid supplies Rubisco with concentrated amounts of CO2 to improve the enzyme’s CO2 capturing activity. If a pyrenoid could be genetically engineered into crops, it could be possible for the plants to capture the same amount of CO2  with less Rubisco, thereby helping them grow with fewer resources. However, this advancement requires understanding the functional roles of proteins involved in building a pyrenoid. 

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New tricks to study the cell's trickiest proteins

Review by Abigail Stanton (MOL, G1)

The cell can be a chaotic place to work. Protein employees of all different types rush from room to room, delivering messages, building needed materials, and working together to keep the cell running smoothly. To learn how any one of these proteins does its job, researchers have to consider how they will structure their experiment to get the type of information that they need. One approach is observing the protein at work: what does it do on a normal day? How does it interact with its coworkers? Studying a protein in situ (in its original place) gives researchers the best sense of how the protein actually behaves. However, the complex environment of the cell can make it difficult to pick out the contributions of any one protein. To gain more detailed information, the researcher may need to sit the protein down for a one-on-one interview, purifying it away from the other components of the cell for in vitro (in a test tube) experiments. However, a protein’s behavior alone may be very different from how it acts surrounded by a crowd of molecules. To create the most useful experiment possible, researchers need to find ways to combine the context of in situ studies with the detail and experimental control of in vitro work. 

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Prince, perception and purple: The colorful world of wild hummingbirds

Review written by Jarome Ali (EEB, G4)

Who is the funkiest musician of all time, and why is it Prince? And what does this have to do with hummingbirds? 

Central to Prince’s aesthetic was his tasteful use of purple, so much so that Pantone Color Institute released a shade of purple in his honor. Prince was on to something. Purple is not just the color of royalty, but it is also unique among the colors we can see--it is nonspectral.

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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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