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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The moment-to-moment pitch dynamics of child-directed speech shape toddlers’ attention and learning

Review written by Liza Mankovskaya (SLA, G7)

Have you ever wondered why we tend to talk to children in a different way than we speak to adults? You might think there isn’t much to it. After all, kids are cute, so adults melt, and hence - “baby talk.” Yet, this difference serves a very important purpose. Several decades of studies have shown that children, from young infants to toddlers, prefer this kind of speech; most importantly, when exposed to speech directed to them in this way, children are more engaged and learn more. But why? We can first consider the differences between speech to children, and speech between adults. One of the most recognizable ways in which caregivers tend to speak to children--child-directed-speech (CDS)--is characterized by significant variation in pitch and intonation. Compared to CDS, “adult” voice and intonations are much more monotonous, so children have a harder time concentrating. Thus, researchers believe that the overall higher level of engagement engendered by CDS promotes learning in children. What is less known, however, is how children process and learn from specific patterns of stress and intonation of CDS on the level of individual words. Recently, Princeton researchers Mira Nencheva, Elise Piazza, and Professor Casey Lew-Williams in the department of Psychology took on exactly this question. They identified specific ways in which caregivers’ pitch changed throughout a word (pitch contours) of CDS in English and analyzed how engaged  two-year-old children were during these different pitch contours and how well they learned novel words that followed these contours. Their findings provide a sub-second frame for understanding the mechanisms and features of CDS that make it optimal for children as they listen to CDS in real time. 

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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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New mathematical insights into fusion equilibria

Review written by Jaydeep Singh (MATH, G2)

Princeton scientists have long been at the forefront of research into nuclear fusion, a challenging process in which light atomic nuclei—hydrogen, for example—are chemically fused together to form heavier elements. The process releases immense amounts of energy, and is a promising approach for meeting the world’s energy needs. Early research dating from the post-war period explored designs for fusion-based weapons, but quickly interest turned to the process of harnessing fusion to generate usable electricity. Fusion research is a vast field encompassing both theoretical and experimental work, and it is not hard to see why controlled fusion remains a difficult problem after almost a century of progress: a prerequisite to achieving the fusion of light ions is the ability to super-heat the ions, in the form of a plasma, up to temperatures of 108 Kelvin within large reactors. To do this, all while maintaining the ability to confine and control the plasma, is no easy engineering feat.

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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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#MeToo? Perceptions of sexual harassment depend on the victim’s femininity

Review written by Leon Mait (PSY, G2)

In October 2017, actress Alyssa Milano tweeted a call for women who had been sexually harassed to reply to her post saying “Me too”, aiming to give the public a sense of how pervasive the experience of sexual harassment is. This ignited the Me Too movement as we know it. However, ten years earlier, social activist Tarana Burke had already started using the phrase on her Myspace page to promote empowerment among women of color who had been sexually abused. Milano did later credit Burke with coining the phrase, but the fact that it took a White woman to bring national attention to a social movement spearheaded by a Black woman is telling.

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Using virtual reality to demonstrate the environmental reinstatement effect

Written by Paula Brooks (PNI, G4)

Walking through your old high school might release a flood of memories that were locked away for years, perhaps even a decade (or more)! Walking through the cafeteria might remind you of the time you almost scared the timid new girl when you boldly walked up to her to invite her to join your friend group for lunch. Or maybe, going past the gym might bring back the memory of when you face planted in front of the entire class while attempting to do the high jump. (Full disclosure: Both of these things happened to me.)

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The development of visual-spatial biases in children

Written by Munisa Said (PSY, 2022) & Crystal Lee (PSY, GS2)

How good are you at finding Waldo? Whether you’re good or bad at it, finding Waldo is not a trivial task. To do so, you must be able to direct your attention to a specific location in a scene, process a massive amount of noisy input, and, finally, make sense of it. Tasks that you perform in your everyday life like reading, driving, cooking--and yes, finding Waldo--all depend on your ability to direct your visuo-spatial attention, the attentional mechanism that allows you to select information from a specific location in space for processing, as well as filter out irrelevant information from other locations. 

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