The question of what drives animals to cooperate with one other is a compelling one. After all, such behavior contradicts the notion lodged in popular imagination that nature is dominated by ruthless Darwinian battles among feral creatures. Yet, these instances of cooperation serve as a reminder that looking out for others is not limited to the Homo sapiens realm. Several explanations for cooperation in social animals exist, but perhaps the most well-established is kin selection: the idea that organisms can indirectly boost their own fitness by performing actions that help ensure the survival of those with whom they share genetic information.
All the marvelous biology we see, from the smallest bugs to the largest trees, is driven by behavior, function, and characteristics of individual cells. The activity of these cells is driven by molecules called proteins, and different cells derive their different characteristics by which specific proteins they use to carry out necessary biological processes. The proteins that are built within cells are determined by which genes of an organism’s DNA are decoded and transcribed into RNA, the blueprint for protein construction. Modern techniques in genetics measure which genes in a tissue are transcribed, in an effort to infer the drivers of such tissues’ biological activity and thus elucidate which functional characteristics are important in a given tissue. Spatially resolved transcriptomics, a subset of these methods, lets biologists and practitioners view which genes are transcribed and to what level (called gene expression) but in a spatial context, making it clear what location within a tissue slice each gene is expressed.
At first glance, Caenorhabditis elegans might not look like much. Measuring in at about 1 mm, these laboratory worms have much simpler biology than your average human. However, this simplicity makes them convenient subjects to study the most basic functions of life because their entire lives from birth to reproduction to death play out over the course of weeks instead of decades. The Murphy Lab in the Department of Molecular Biology at Princeton uses these worms to ask questions about the aging process: what happens at a molecular level that causes us to age, and how can we promote longer, healthier lives?
There is a widespread misconception that deserts, arid and extreme in climate, are unaffected by climate change. The truth is that deserts are disproportionately impacted by climate change and are projected to see great changes in the distributions of fauna and the behavior of such species due to current warming trends. Though both cold and warm deserts will be affected by these changes, warm deserts have already sustained damage. Indeed, the surprisingly diverse region has suffered much due to climate change, and the ecosystem harbored by this biome constantly lives at its physiological limits. Further changes to these regions would create conditions even more extreme than those to which these species have already adapted, possibly leading to extinction.
Review written by Adelaide Minerva (PNI, G4) and Rebekah Rashford (PNI, G5)
Throughout the COVID pandemic, many of us were faced with profound levels of social isolation which took a toll on both our mental and physical health. This has been especially detrimental for children, whose brains and social skills are still developing. Normally, social experience in early life plays a crucial role in guiding this development; but what happens when that guidance is no longer present? Disruptions to the early social environment have been seen to negatively impact other social species besides humans, such as mice, fish, and some insects. Studying how social isolation may disrupt the development of these highly social species can provide insight into the neural mechanisms underlying both typical and aberrant behavior at a level of detail not currently possible in human subjects. Taking advantage of one of these highly social species, Dr. Yan Wang and colleagues in the departments of Ecology & Evolutionary Biology and the Center for Biophysics at Princeton used bumblebees to measure the effects of early life social isolation on behavior, gene expression, and whole-brain neuroanatomy.
Early life adversity, ranging from physical and emotional abuse, neglect, and violence, to poverty and unstable home environments, can have an enduring toll on child development. Some children who experience early life adversity may experience detrimental effects in the moment but develop into adults without pathological behavior. On the other hand, for certain children, the impacts of early life adversity increase the likelihood that they will develop neuropsychiatric disorders as adults. For instance, anxiety disorders are more prevalent amongst survivors of early life adversity compared to the general population. Although diverse in the symptoms they present and the treatments they require, anxiety disorders share one feature in common: heightened levels of anxiety. Normally, anxiety helps us steer clear of dangers. However, if ramped up into overdrive, excessive levels of anxiety can fuel a range of maladaptive behaviors.
Socioeconomic status (SES), often simplified as absolute material wealth, is often linked to a variety of human health metrics. At a fundamental level, it makes sense that higher SES likely corresponds with access to better medical services, and in turn, better overall health. Studies have shown that, indeed, higher SES is associated with better human health, but the majority of this data comes from high-income countries (HICs). Despite the growing amount of scientific evidence for the apparent gradients in disease risk and survival explained by access to medical care and other health-related lifestyle factors, we cannot be certain that these trends are universal. Understanding the relationship between SES and health is crucial for policy design and to ensure we make economic decisions that do not negatively impact overall human health. Ultimately, the relationships between SES and health can be used to motivate positive change that benefits all of humanity.
On the savannas of Kenya, a battle has been waged for centuries. The landscape hints at how this battle has shaped the entire ecosystem, but it must be viewed from far above. From just a few meters above ground level, the telltale signs are still invisible. However, from the vantage point offered by drone photography or satellite imagery, a clear pattern emerges. Patches of vegetation are spotted across the savanna, in a regular hexagonal layout. This kind of order in the natural world fascinates biologists and begs for an explanation. Researchers at Princeton have been investigating how warring termite colonies (or insect colonies in general), and the underlying resource distribution can drive the emergence of order in the savanna landscape.
Even in the microscopic world, survival of the fittest can make for relentless, and creative, competition. With a limited amount of resources to go around, some bacteria will play dirty to make sure they get their fair share. Actinoplanes sp. SE50/110, a bacterium that lives in the soil, has developed a strategy to fight off competitors: by producing a specialized sugar called acarbose, it can block proteins responsible for sugar uptake and metabolism in its microbial neighbors. This inhibits the growth of other bacteria, leaving more food for Actinoplanes to enjoy.
Adeno-associated viruses (AAVs) are some of the most widely used recombinant viral technologies—those that combine different genes to produce unique viral vectors, or tools that convey genetic material into cells—in modern neuroscience. Because they are incapable of being replicated within cells, recombinant AAVs are commonly used in neuroscience research as a means of expressing genes in specific cells. By expressing genes that heighten or dampen the function of certain cells, researchers are able to identify the functions of particular neural circuits.1 This approach can provide scientists with insight into the mechanisms underlying neurobiological processes. To make such circuit-related discoveries, AAVs are typically injected into certain brain regions of animal subjects. After an incubation period, some AAVs encoding fluorescent tracers can induce cells to fluoresce under specialized microscopes, enabling scientists to visualize particular neural circuitry. Furthermore, AAVs have demonstrated clinical potential; for example, AAVs have been used to replenish certain proteins in the treatment of diseases like congenital blindness 2, 3 and spinal muscular atrophy.4, 5 AAV is also currently being investigated as a potential means of treating other brain disorders, including Parkinson’s disease, Alzheimer’s disease, amyotrophic lateral sclerosis (ALS), and more.6