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.
In this episode of The Highlights, we're joined by Nicole Templeman, an assistant professor of biology at the University of Victoria. As a postdoctoral fellow at Princeton, Templeman was part of molecular biology professor Coleen Murphy’s lab, where she studied reproductive aging. We discuss her most recent publication, which explores how inter-tissue communication affects rate of “age-related reproductive decline,” and how the COVID-19 pandemic has affected her lab.
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.
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?
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).
“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.
Review written by Sara Camilli (QCB) and Adelaide Minerva (PNI)
As we go about our daily lives, we often do not consciously think about all the real-world landmarks that we use to position ourselves in space. Yet, as we walk to our local coffee shop or go for a jog in the park, our brain is continuously updating its internal representation of our location, which is critical to our ability to navigate the world. However, we also know that humans and a number of animals can update this internal representation of their position in space even in the absence of external cues. This phenomenon, known as path integration, involves interaction between the parietal cortex, medial entorhinal cortex (MEC), and hippocampus regions of the brain. Prior work has shown that grid cells in the MEC have firing fields that are arrayed in a hexagonal lattice, tiling an environment. Further, there is evidence of inputs to the MEC that encode the velocity at which an animal is moving, which can be used to update the animal’s internal representation of its position. Together, these features support a role of the MEC in path integration.