Understanding the entirety of the Vibrio cholerae biofilm lifecycle: First insights into biofilm dispersal

Review written by Kimberly Sabsay (QCB, G2)

Individual cells go through life cycles, in which they grow and prepare for cell division. Similarly, in certain bacteria, groups of cells go through a synergistic cycle involving the formation and disassembly of biofilms. Biofilms are essentially groups of cells that surround themselves in layers of self-made extracellular matrix proteins and polysaccharides. A biofilm is a way for cells to protect themselves from dislocation or death by predation and are present in both beneficial and pathogenic bacterial microbiomes. The sticky extracellular matrix is a structure that pathogens such as Vibrio cholerae (the bacteria that causes Cholera) can hide in to avoid detection by immune cells and thus increase their virulence. In this way, biofilms essentially provide protective armor for bacterial cells that inhibits our ability to fight pathogenic infections. 

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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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Biophysical modeling of liquid-liquid interactions helps scientists understand cell division

Review written by Alexandra Libby (PNI)

Cell division is one of the most important and well-studied biological processes. Organisms generate new cells in order to grow and reproduce (Figure 1); the types of cell division responsible for each of these goals are called mitosis and meiosis, respectively. Like many biological processes, cell division involves a well-timed, complex coordination of proteins and cellular machinery. Disrupted division can lead to a multitude of problems including genetic mutations, cell death, and cancer (Zhivotovsky and Orrenius, 2010). 

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Life: Like oil and water? Part II

Part II of our series into the phenomenon of phase separation that is changing how biologists understand cellular biology

Review written by Xinyang (David) Bing (LSI)

“Repression condensates”

“For liquid-liquid phase separation, Princeton is the center of the universe, and my work benefited from collaborations and interactions with Cliff Brangwynne's lab.” 

This is how Dr. Nicholas Treen, from the lab of Mike Levine, described his close working relationship with the neighboring Brangwynne lab. In his latest publication, he and his collaborators set out to describe a novel type of condensate formation in the nucleus involved in gene silencing. 

The first cell divisions of a newly fertilized embryo are arguably the most instrumental events that occur throughout the life of an animal. During early embryonic development, an intricate web of processes must occur coordinately to lay the blueprint for the developing organism. Like a set of dominoes, every gene that is expressed during early developmental processes leads to consequences downstream during later developmental stages. Even slight errors may lead to a malfunctioning embryo and certain death of the animal. Therefore, all animals have their own set of developmental “blueprints” that necessitate massive numbers of genes be expressed in a tightly controlled manner, both in terms of timing and levels. 

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Life: Like oil and water?

“Rediscovery” of a decades-old physics idea reignites the fields of cellular and molecular biology

Review written by Xinyang (David) Bing (LSI)

Lava lamps are fluorescent mixtures of oil and water that are immiscible and, when heated, float around, generating hypnotizing patterns that lull you to sleep. Now, biologists are seriously considering the possibility that the same physics that govern lava lamps may also control almost everything that goes on inside our cells.1 Walk through the halls of MIT and Harvard, Oxford and Cambridge, or of course Princeton, and you would likely hear what everybody is talking about: liquid-liquid phase separation.

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